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10.1586 /EGH.12.12 301
ISSN 1747- 4124
© 2012 Expert Reviews Ltd
www.expert-reviews.com
ReviewReview
Chun Seng Lee*,
Ronan Leen,
Colm O’Morain and
Deirdre McNamara
Department of Clinical Medicine,
Trinity Centre for Health Sciences,
Adelaide and Meath Hospital,
Dublin, Ireland
*Author for correspondence:
Tel.: +353 1 414 2000
Fax: +353 1 414 3850
leecs@tcd.ie
Colorectal cancer (CRC) screening has been shown to be effective in reducing CRC incidence and
mortality. There are currently a number of screening modalities available for implementation into
a population-based CRC screening program. Each screening method offers different strengths
but also possesses its own limitations as a population-based screening strategy. We review the
current evidence base for accepted CRC screening tools and evaluate their merits alongside their
challenges in fulfilling their role in the detection of CRC. We also aim to provide an outlook on
the demands of a low-risk population-based CRC screening program with a view to providing
insight as to which modality would best suit current and future needs.
Screening for colorectal cancer:
what fits best?
Expert Rev. Gastroenterol. Hepatol. 6(3), 301–312 (2012)
Keywor ds: colonoscopy • colorectal cancer • CT colonography • fecal blood test • screening • sigmoidoscopy
Expert Review of Gastroenterology & Hepatology
2012
6
3
301
312
© 2012 Expert Reviews Ltd
10.1586/EGH.12.12
1747-4124
1747-4132
Screening for colorectal cancer
Lee, Leen, O’Morain & McNamara
Expert Rev. Gastroenterol. Hepatol.
Review
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Upon compleon of this acvity, parcipants will be able to:
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Financial & competing interests disclosure
P
ublisher
Elisa Manzotti
Editorial Director, Future Science Group, London, UK.
Disclosure: Elisa Manzotti has disclosed no relevant financial relationships.
CME A
uthor
Laurie Barclay, MD
Freelance writer and reviewer, Medscape, LLC.
Disclosure: Laurie Barclay, MD, has disclosed no relevant financial relationships.
A
uthors
And
C
rEdEn tiAls
Chun Seng Lee, MB, MRCPI
Department of Clinical Medicine, Trinity Centre for Health Sciences, Adelaide and Meath Hospital, Dublin, Ireland.
Disclosure: Chun Seng Lee, MB, MRCPI, has disclosed no relevant financial relationships.
Ronan Leen, MB, MRCPUK
Department of Clinical Medicine, Trinity Centre for Health Sciences, Adelaide and Meath Hospital, Dublin, Ireland.
Disclosure: Ronan Leen, MB, MRCPUK, has disclosed no relevant financial relationships.
Colm O’Morain, DSc, MD, FRCP, FRCPI
Department of Clinical Medicine, Trinity Centre for Health Sciences, Adelaide and Meath Hospital, Dublin, Ireland.
Disclosure: Colm O’Morain, DSc, MD, FRCP, FRCPI, has disclosed no relevant financial relationships.
Deirdre McNamara, MD, FRCP(Edin), FRCPI
Department of Clinical Medicine, Trinity Centre for Health Sciences, Adelaide and Meath Hospital, Dublin, Ireland.
Disclosure: Deirdre McNamara, MD, FRCP(Edin), FRCPI, has disclosed no relevant financial relationships.
Colorectal cancer (CRC) is an important health issue worldwide.
It is the most common malignancy in Europe (excluding non-
melanoma skin cancers) and the second most common in terms
of cancer-related mortality [1]. Although decreasing in incidence,
CRC remains the third most common cancer in the USA and is
the third leading cause of cancer deaths [2]. By contrast, in Europe,
there seems to be a trend of modest increase in incidence [1].
Survival and mortality from CRC has seen an improvement over
the past 30 years [3]. This is in no small part due to earlier detection
of the disease and also treatment advances in the management of
CRC [4]. Despite this, the economic burden of this disease remains
huge. Recent estimates from the National Cancer Institute have
put the cost of CRC cancer care in the tune of US$12.1 billion
in 2006, second only to breast cancer and accounting for 12%
of the total expenditure for cancer care every year [201]. This is in
stark contrast to the US$7.49 billion estimated in a previous study
for CRC cancer care in 2000. In this study, projections based on
trends at that time indicated that the total cost of CRC cancer care
was set to increase by a further 89% by the year 2020 [5]. As the
current updated figure has already increased by more than 60%
in just 6 years since the year 2000, we are more than likely to see
a healthcare bill in excess of the original US$14 billion estimated
for this disease. The reason for this dramatic increase is multifac-
torial, but its impact on the delivery of healthcare in developed
countries, and indeed worldwide, is unarguably profound. There
is therefore a compelling need to contain the spiraling cost of this
disease. To achieve this, healthcare providers will need to reduce
its incidence, optimize cancer care for cost efficiency and avert
early mortality from cancer, which is estimated to result in an
average 15 years of life lost per patient. All these points underpin
the rationale for CRC, screening, and there is now a substantial
body of evidence to show screening does reduce the incidence
and mortality of CRC [6]. However, there are controversies as to
the modality that would best serve the purpose of screening in a
general population. Different methods offer unique strengths and
herein we review the most frequent modalities employed and their
cost–effectiveness in an attempt to determine ‘what fits best’ as a
general population screening tool (Table 1).
Role for CRC screening
CRC fulfills the WHO’s criteria for screening through early
detection of the disease and/or its precursors polyps [7]. Compared
with other cancer screening programs, CRC screening has been
shown to be cost effective [8]. There are a range of modalities for
CRC screening, and the recent joint guideline from the American
Cancer Society, the Multi-Society Task Force on Colorectal Cancer
and the American College of Radiology broadly grouped tests
into those that can primarily detect cancer early (stool-based tests)
and structural tests that can detect cancer and also adenomatous
polyps such as colonoscopy, flexible sigmoidoscopy (FS) and
CT colonography [9]. Detection of adenomatous polyps has the
potential to prevent future cancers via therapeutic measures such
as polypectomy. This is particularly relevant for polyps that exhibit
features that harbor significantly increased malignant potential,
such as large size or the presence of high-grade dysplasia on
histology. Polyps larger than 1 cm in size and/or display high-grade
dysplasia on histology are often termed ‘advanced adenomas.’ The
guideline did not recommend a single specific screening modality;
rather it encouraged medical practitioners to fully appraise patients
of the various options and to allow them to choose. However,
they did emphasize that cancer prevention, rather than cancer
detection, should be the primary goal [9].
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Screening for colorectal cancer Review
Different screening modalities
Stool-based tests
CRC screening with stool tests typically involves a two-stage
approach, with patients positive for the test being referred for
colonoscopy. Traditional guaiac-based stool tests (guaiac-based
fecal occult blood test [gFOBT]) and immunochemical-based
tests (fecal immunological test [FIT]) both check for the presence
of occult blood in the stool, which is associated with advanced
colorectal neoplasia and cancer. A newer stool DNA test checks
for the presence of mutations associated with colorectal neoplasia.
However, this test is not widely available, and the results are still
not very further accurate or reliable enough and, as such, are not
discussed further in this review [1 0 ,11] .
Guaiac-based fecal occult blood tests
gFOBT is the earliest stool-based test developed for CRC screening.
Based on the peroxidase activity of heme reacting together with
hydrogen peroxide and a resin found in guaiac to give off a blue
color, it is still one of the most widely used screening modalities
worldwide [1 2 ,1 3] . Its efficacy has been confirmed in major prospec-
tive trials, with patients undergoing regular gFOBT testing having a
reduction of 16% in relative risk for CRC mortality [6]. It is cheap to
perform and can be carried out conveniently in a physician’s office.
However, there are several technical issues with its use, such as
the qualitative color change, which can be difficult to interpret,
necessitating formal training of personnel to avoid misreading of
the result [14 ]. Dietary restrictions are encouraged prior to gFOBT
testing to minimize the effects of a heme-rich diet (red meats
and liver) and of plant peroxidases on the specificity of the test
[15–17]. Medications such as aspirin and NSAIDs known to induce
gastrointestinal bleeding have also to be withheld as the detection
of heme in the stool does not differentiate between an upper or
lower gastrointestinal source, therefore generating false-positive
results [18 ]. Usually stool samples are tested from three separate
bowel movements collected by patients. Testing of gFOBT on
stool samples obtained in the physician’s clinic during a digital
rectal examination is not very sensitive and is not recommended,
although it is widely practiced [ 9].
Overall, one-time sensitivity for detecting CRC using gFOBT
is low, ranging from 12.9 to 50% although a study using a more
sensitive gFOBT (Hemoccult® SENSA®, Beckman Coulter, Inc., CA,
USA) has reported a sensitivity of 85.7% [19]. When used repeatedly
in the setting of an annual or biennial CRC screening program, the
overall sensitivity of gFOBT for detecting CRC is between 51.1 and
72.2%, with a positive-predictive value ranging from 8.0 to 17%
[19]. A study using Hemoccult SENSA in this setting has reported
sensitivity as high as 100% but with a lower positive-predictive value
range of 2.4–5.5% [20]. It is important to note that the performance
of gFOBT is highly dependent on patient compliance with repeated
testing, and there could be selection bias confounding the results in
these studies, meaning its actual performance in the real world could
well be lower than currently observed [9, 21] . It is also to be noted that
the US Preventive Services Task Force no longer recommend the use
of traditional gFOBT because of its poor sensitivity, in preference
for gFOBT with higher sensitivity such as Hemoccult SENSA for
guaiac-based fecal testing for CRC.
Fecal immunological test
FIT, in turn, detects the protein globin that is unique to the human
species by utilizing monoclonal antibodies raised against them. As
Table 1. Summary of currently available screening modalities, their performance in detecting
colorectal cancer and polyps, and their effect on colorectal cancer incidence and mortality.
Screening
modality
Approach
to
screening
Recom-
mended
interval
Tes t
sensitivity
for CRC
(%)
Tes t
specificity
for CRC
(%)
Tes t
sensitivity
for
advanced
adenoma
(%)
Tes t
specificity
for
advanced
adenoma
(%)
Incidence
reduction
CRC (%)
Mortality
reduction
CRC (%)
Ref.
Stool-based examinations
gFOBT Two step Annual or
biennal
12.9 – 85 8 0 – 97. 7 4–33 >80 16 [6,19, 28, 98]
FIT Two step Annual or
biennal
81.8 –10 0 87. 5 –96.9 27–56.8 91 .4 – 9 7.3 [33–38]
Fecal DNA Two step Uncertain 25–86 73–96 15–57 84–96 [97]
Colon examinations
Colonoscopy One step 10 year 95 88–98 67–76 50–65 [39,4 0,53]
Sigmoidoscopy Two step 5 year 95 83 59.6 31–33 38–43 [53,64,67]
CT
colonography
Two step 5 year 96 90†
78–90‡
86–89†
86–89‡
[72 ,74, 99]
†Performance of CT colonography for detection of adenomas ≥10 mm in size.
‡Performance of CT colonography for detection of adenomas 6–9 mm in size.
CRC: Colorectal cancer; CT: Computed tomography; FIT: Fecal immunological test; gFOBT: Guaiac-based fecal occult blood test.
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globin is destroyed by proteases during transit through the small
intestine, its presence in stool highly suggests blood from a colonic
origin [22, 23] . FIT is not dependent on peroxidase activity, and there
is no need to undergo any dietary or medication restrictions as
there is with gFOBT. Unlike gFOBT, the readings from FIT are
quantitative, with measurements of the amount of globin being
read by enzyme-linked immunosorbent assay and a numerical value
produced as output [24]. The quantitative nature of the test removes
ambiguity once a cutoff limit for positivity is set. The cutoff limit
can also be adjusted to optimize the detection of advanced adeno-
mas and cancers in different local population groups [25,26]. It also
has a lower detection limit for occult blood and has been shown
in several studies to have increased sensitivity and specificity com-
pared with gFOBT [27,28]. Less stool sample requirements (one or
two stool samples for FIT) and ease of use of the collection kit
can improve patient adherence with screening [29]. As it is a newer
test, its effectiveness in reducing CRC incidence and mortality has
not been proven in any direct study to be superior to gFOBT.
Furthermore, the performance between different commercially
available FITs can vary, and regular assessment of its sensitivity and
specificity will be needed as the technology develops [30]. There are
also technical issues such as false-negative results because of delayed
processing of the sample. This occurs as a result of globin degrada-
tion and is a temperature-dependent process based on in vitro stud-
ies [31]. This has a detrimental impact on the reliability of the test in
practice, with one Italian study noting reduced test positivity during
the summer months for a regional CRC screening program [32].
Therefore, logistical issues are of significance and should be given
particular consideration for any national CRC screening program.
Overall, the sensitivity of FIT for the detection of CRC is
reported to range from 81.8 to 100% and from 27 to 56.8%
for the detection of advanced adenomas. The specificities for
detecting CRC and advanced adenomas were 87.5–96.9% and
91.4–97.3%, respectively [33–3 8].
Colon examinations
Colonoscopy
Colonoscopy is one of the most common screening modalities
employed for CRC screening in the USA and has several advantages.
It allows for direct visualization of the colonic mucosa and the whole
colon can be assessed. Polyps discovered during the procedure can
be readily removed by polypectomy. There is evidence from obser-
vational and case-controlled studies that polypectomy can reduce
the incidence of CRC [39,40]. Prospective randomized trials looking
into this effect are currently underway [202,203]. Colonoscopy is the
only method that offers a one-step approach to CRC screening: all
the other CRC screening tests have to further refer subjects who test
positive for full colonic evaluation with colonoscopy. This one-step
approach streamlines the workflow, reduces the number of visits
subjects have to attend and may even enhance patient compliance
with CRC screening guidelines because of the extended recom-
mended interval between retesting: 10 years for a negative screening
colonoscopy [41]. However, colonoscopy is an invasive procedure
and carries with it an inherent risk, although the risk is low. Studies
reported an overall complication rate of 2.9–5 per 1000 endoscopies
and a perforation rate of 0.9–1.8 per 1000 endoscopies [42 ,43] . A
screening colonoscopy program also reported a complication rate
of 0.1% [44]. Subjects have to undergo the arduous task of having to
take bowel preparation to cleanse the bowel prior to colonoscopy
and the procedure itself can often be uncomfortable and poorly
tolerated. Sedation is commonly used to improve patient comfort
and compliance during the procedure but this has its own inher-
ent risks and drawbacks [45]. Newer technologies such as the use
of CO2 insufflation instead of air during procedure may help to
decrease patient discomfort, leading to better patient satisfaction
and attendance [46].
Colonoscopy as a screening modality is also heavily operator
dependent. Competency with this procedure is absolutely vital, so
that the whole colonic mucosa is visualized (cecal intubation) and
lesions are properly identified (adenoma detection) with minimal
patient discomfort (patient satisfaction) and complications. These
all have an sequential impact on the ability to detect CRC, and
there is evidence that expertise is a risk factor for missed CRCs
during colonoscopy [47]. It is therefore of paramount importance
that the quality of the screening colonoscopy is ensured to achieve
the maximal efficacy from this modality. Training of specialist
personnel and the regular auditing of key performance indicators
in a colonoscopy-based screening program will help to standardize
clinical practice and upkeep the requirements for implementing
this strategy [48]. Of the quality indicators for screening
colonoscopies, adenoma detection rate (ADR) merits particular
mention. Kaminski et al. showed that the only two factors that
determined the risk of interval cancer were the patient’s age and
the endoscopist’s ADR. A total of 42 interval CRC were identified
during a period of 188,788 person-years. The hazard ratio between
endoscopists who had an ADR greater than 20% and those with
an ADR less than 20% was over 10.75 for the development of
interval CRC [49].
Colonoscopy is often used as the ‘gold standard’ for the detection
of CRC and adenomatous polyps with which other tests are com-
pared. There are no studies that actually define the ‘true’ performance
of this procedure but it is estimated to have sensitivity and specific-
ity of 95% and 88–98%, respectively [21]. However, a study using
back-to-back colonoscopy reported a significant adenoma miss rate
of 6% for lesions more than 1 cm in size, whereas a study compar-
ing colonoscopy with CT colonography (CTC) suggested that this
miss rate could be as high as 12% [50,51]. A population-based study
looking at right-sided CRC has indicated that approximately 4% of
right-sided CRC are missed on colonoscopy [52].
There are several lines of evidence that have shown the efficacy
of colonoscopy in the reduction in CRC incidence and CRC-
related mortality [53]. More controversially, a recent population-
based study verified the protective effect for distal colonic neo-
plasia but no effect on the prevalence of proximal disease. The
reason for this is unclear but missing lesions in the proximal colon
during colonoscopy cannot be ruled out [5 4, 55] .
Flexible sigmoidoscopy
In contrast to colonoscopy, FS only inspects the left side of the
colon for neoplasia. The rationale behind using FS as a screening
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tool in CRC hinges on observations that distal CRC are more com-
mon than proximal CRC; sigmoidoscopy and polypectomy prevent
the development of distal CRC; and proximal colonic lesions are
frequently associated with advanced distal disease [56–58]. Its usage
is usually in a two-stage model, with FS used in conjunction with
colonoscopy for initial FS-positive patients. FS is safe, quick and can
be performed without sedation, negating the need for admission to
the day ward for prolonged observation, unlike colonoscopy which
is commonly performed with conscious sedation. Nonphysician
healthcare workers, such as nurses and physician assistants, can
also be trained in this relatively straightforward procedure, which
improves capacity and accessibility as a CRC screening program
[59]. Favorable patient factors supporting FS as a screening tool
include the relative ease of use and tolerability of bowel enema, rather
than the large volume oral preparations required for colonoscopy,
resulting in better patient acceptability and uptake rates [60].
However, there are issues that pose a challenge with the use of
FS as a screening tool. While the strategy of FS with follow-up
colonoscopy may actually identify up to 80% of all advanced
neoplasias, there are specific issues regarding proximal colonic
lesions. Previous studies have shown that around 50% of proximal
colonic neoplasia will be missed if the decision to proceed with
full colonoscopy is based on distal colonic pathology alone [61,62].
Furthermore, the incidence of proximal colonic pathology increases
with age, and there is evidence to show that performing FS for
screening in women would result in a higher proximal colonic lesion
miss rate than observed for a matched male cohort [63]. These have
given rise to concerns that FS as a modality may not be suitable as a
screening tool for certain subgroups of the population at average risk
for developing CRC [63]. It is also interesting that Atkin et al. only
reported a modest decrease in the incidence of proximal CRC in the
their study [64]. Another limitation of FS is the lack of consensus as
to what a ‘full’ sigmoidoscopy constitutes. This is in part because of
the lack of a reliable anatomical landmark by which to reference the
length of colonic mucosa examined. There is therefore a significant
potential for heterogeneity in clinical practice, which will impact
performance. To address this, the US Multi-Society Task Force
on Colorectal Cancer have recommended insertion of FS beyond
40 cm as a quality measure in FS [9]. While this guideline is
helpful in clinical practice, using an absolute length of endoscope
to determine the adequacy of colonic inspection is arbitrary at best
and does not take into account other variables such as patient size
and the presence of diverticular disease. Like colonoscopy, FS has
also been shown to be heavily dependent on the operator for its
efficacy and hence there is a need for implementation of a robust
quality-assurance program alongside the screening strategy [65].
The efficacy of FS in detecting colonic neoplasia and reduc-
ing in CRC mortality has been proven in several case-controlled
and cohort studies [66]. A study using a combination of CTC and
colonoscopy as a gold standard has reported a sensitivity rate of
83.3% for FS in detecting advanced colonic neoplasia [67]. There
are several randomized trials ongoing to further assess the impact
of a CRC screening strategy with FS. One such trial in Norway
failed to show a significant reduction in incidence of CRC with
FS after a follow-up of 7 years [68]. More recently, however, Atkin
et al. reported the results of a multicenter randomized controlled
trial (UK Flexible Sigmoidoscopy Trial), and the group was able
to demonstrate a decrease in the incidence of CRC by 23% in
the intervention group coupled with a reduction in CRC-related
mortality by 31% after a median follow-up of 11.2 years. A bor-
derline significant decrease in overall mortality was also observed
in this study [64]. Segnan et al. similarly showed that in an Italian
randomized controlled trial involving 34,272 subjects, the inci-
dence and mortality of CRC were reduced by 31 and 38%, respec-
tively, with FS over a median follow-up of 10.5 years [69]. Overall,
the results looked promising and one explanation for the lack of
observed benefit in the Norwegian study could be the brevity of
the follow-up period.
CT colonography
CTC involves the imaging of the colon using low-dose ionizing
radiation. Subjects undergoing CTC take oral bowel preparation
similar to colonoscopy. During the procedure, a rectal catheter is
inserted for insufflation to achieve colonic distention, which may
be uncomfortable, although less so when using CO2 insufflation
rather than air. The procedure is quick and requires no sedation.
It is minimally invasive and very safe, with a reported overall
complication rate of 0.02% and perforation rate of 0.009% [ 70].
Subjects found to be positive for polyps on CTC would in turn
proceed to colonoscopy for confirmation of diagnosis and therapy.
Recent advances in this technology, such as multidetector CT and
3D reconstruction imaging, enable high-quality imaging of the
mucosa to be acquired for polyp detection [71].
Pickhardt et al. performed CTC and colonoscopy on the same
day on a cohort of asymptomatic subjects and were able to dem-
onstrate a sensitivity rate of 93.9% for polyps at least 10 mm in
size, whereas sensitivity for colonoscopy was 87.5% for detec-
tion of similar-sized polyps [72]. Specificity for the detection of
lesions more than 10 mm in size was 96% in the study. Increased
polyp size has been shown to be associated with increased risk of
advanced histology such as carcinoma and this is reflected by the
ability of CTC to detect CRC accurately. A recent meta-analysis of
CTC in the detection of CRC involving 11,151 patients reported
a sensitivity rate of 96.1%, comparable to that of colonoscopy,
which had a sensitivity of 94.7% for the detection of CRC [73].
While the detection of CRC and large polyps is highly
accurate with CTC, there are issues regarding the detec-
tion of smaller polyps that are less than 1 cm in size. It was
shown in studies that the sensitivity for detection of polyps
with CTC drops with decreasing polyp size to 59% for polyps
≥5 mm [74]. Current American College of Radiology guidelines
have recommended not reporting polyps smaller than 6 mm
based on the fact that the risk of advanced histology in these
diminutive polyps is low, but there is still a lack of consensus
among the multiple disciplines over this controversial statement
[75,76]. Based on these criteria, it is estimated that approximately
12.2–30% of all screening CTCs will be referred for colonos-
copy [72,74 ]. Another issue of CRC screening with CTC is the
detection of extracolonic findings, which can be present in up
to 70% of subjects being screened [77,78]. Additional resources
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Review Lee, Leen, O’Morain & McNamara
will have to be deployed for further evaluation of these findings,
which may involve exposing asymptomatic subjects to invasive
procedures such as tissue sampling, thereby having an overall
impact on patient safety, patient anxiety and cost–effectiveness
[79]. There are also safety concerns regarding radiation with the
use of CTC but the amount of ionizing radiation used in CTC,
is considered to be low and would be further minimized with
the development of a low-dose regimen [80].
Cost–effectiveness analysis
With the mounting evidence to show that screening for CRC has a
positive impact on the incidence of CRC and CRC-related mortal-
ity, the impetus for rolling out a national CRC screening strategy
is compelling. With a menu of screening options to choose from,
several other factors vital to a successful roll out would have to be
considered, of which cost–effectiveness is one important aspect.
This involves quantifying the benefits and risks for each modality
under consideration. Benefits are usually calculated as the number
of life years or quality-adjusted life years (QALYs) gained, whereas
risks are commonly represented by the costs. Cost–effectiveness
is measured by looking at the cost per additional life-year gained
or cost per additional QALY gained (US$/QALY). It is generally
accepted that measures costing <US$50,000/QALY are considered
to be cost effective in developed countries.
Several cost effective analyses have clearly shown the superiority of
screening over a no-screening strategy [81–83]. Even when compared
with other screening programs, such as those for breast and cervical
cancer, CRC screening remains a cost-effective measure [ 8].
As to which test is the most cost effective in terms of CRC screen-
ing is a subject that is hotly debated, with evidence supporting
each of the aforementioned modalities [84–89]. Cost–effectiveness
analysis is mainly carried out by modeling, and heterogeneity
in the comparative research methodology employed in different
studies makes it difficult to draw comparisons and to decipher
the ‘true’ cost–effectiveness between different screening strategies.
Furthermore, cost–effectiveness analysis in a given healthcare
delivery structure may not be generalizable to other healthcare
structures. For example, there are studies to suggest that FIT is a
less cost-effective strategy when compared with gFOBT for CRC
screening [90 ,91]. By contrast, a health technology assessment of
a population-based CRC screening program in Ireland found
that biennial FIT screening at 55–74 years of age is the most
cost-effective measure when compared with biennial gFOBT for
the same age group and with for screening using FS [92]. Based
on these findings, a population-based CRC screening program
is currently being rolled out in Ireland using FIT in a two-stage
screening strategy [204].
A combination of screening modalities, such as gFOBT alternating
with FS, has also been shown to be potentially very cost effective [82] .
On the other hand, CTC was found to be costly in comparison with
other screening strategies, such as colonoscopy, in the US healthcare
setting. This enabled decision-makers to conclude that CTC is not
a cost-effective measure for CRC screening, and the Centers for
Medicare and Medicaid Services has denied coverage of CTC for
CRC screening (Table 2).
Conclusion & future directions
CRC screening is effective, with supportive evidence available
from several long-term analyses of national programs, including
the UK and USA. The screening programs in both countries
Table 2. Summary of cost–effectiveness analysis of each colorectal cancer screening strategy for
healthcare systems in different countries.
Screening strategy,
interval
Knudsen et al., USA [91] Heitman et al., Canada [10 0] HTA-HIQA Report, Ireland [9 2]
Life-years
gained per
1000 subjects
(vs no
screening)
Cost per
life-year
gained
(US$)
QALYs gained
per 1000
subjects
(vs no
screening)
Cost per QALY
gained (CAN$)
QALYs gained
per 1000
subjects
(vs no
screening)
Cost per
QALY gained
(€)
gFOBT, yearly 81.1†10†12‡15,991‡
gF OBT, biennal 7.6 4428
FI T, yearly 80.1 800 12‡2219‡
FI T, biennal 23.7 1696
Colonoscopy, 10 yearly 86.7 2200 41 4870
Sigmoidoscopy, 5 yearly 75 140 0 36 10,008
Sigmoidoscopy,
once-off
5.8 589
CT colonography,
5 yearly
85.3 8900 41 12,50 0
†Cost analysis based on high-performance version of gFOBT.
‡Cost analysis based on high-performance version of gFOBT and FIT.
FIT: Fecal immunological test; gFOBT: Guaiac-based fecal occult blood test; HTA -HIQA: Health technology assessment – Health Information and Quality Authority;
QALY: Quality-adjusted life year.
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307
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Screening for colorectal cancer Review
vary, but both are beginning to show a trend of reduced
CRC mortality and incidence [1,4,93 ]. There are a number of
acceptable tools by which CRC screening can be carried out,
as evident in this review. However, the test of choice is still a
question that is yet to be answered. While the recommendation
by the US Preventative Task Force of making the patient aware
of the full range of options available empowers the patient to
make his/her own choice and allows for degrees of freedom
for the physicians [94], having a single CRC screening strategy
for a population-based CRC screening program is likely to be
preferable to ensure homogeneity, equitable access and arguably
efficiency in a resource-finite setting. It is also likely that no one
single test is going to be the most suitable for CRC screening in
different low-risk population groups and healthcare systems, in
particularly when patient acceptance and preference are taken
into account. Our initial experience of a pilot study of population
based CRC screening using FIT has demonstrated a good uptake
rate for screening in the target population and efficacy in the
detection of CRC and advanced polyps [95]. Several studies have
also suggested good patient acceptance and uptake with FIT
[29]. These patient factors, along with reliability, accessibility and
ease of use, together with positive data from cost–effectiveness
studies, position FIT very strongly as the test of choice for future
CRC screening programs. However, as further research into
enhancing the performance of existing technologies and further
development of newer alternative methods such as fecal DNA
tests and colonic capsule endoscopy come to light, the pendulum
may well swing in their favor in the near future [96,97,202]. Several
ongoing comparison studies are awaited and may also help to
clarify this matter.
So, in conclusion, current evidence supports all aforemen-
tioned modalities as effective screening tools. FIT is one of
the best currently available strategies for the introduction of a
population-based CRC screening program. However, as tech-
nology advances and indeed the epidemiology of CRC changes,
healthcare providers will need to adapt strategies and should
be prepared to review the performance of a program regularly
to ensure that the process employed is the best fit for their
population at any given time.
Most importantly, it is clearer than ever that not screening is
no longer a befitting proposition, and ways to optimize adher-
ence to CRC screening will be the way forward for the general
population.
Expert commentary
The evidence for CRC screening in detecting and preventing
CRC is mounting. This serves as an impetus for the introduc-
tion of population-based CRC screening programs, both to save
lives and as a means of ‘bending the curve’ in the ever-rising
cost of cancer care. This review highlights the currently avail-
able modalities of screening and reviewed the pros and cons of
each for their inclusion in a population-based screening strat-
egy. Current evidence favors FIT as one of the best modalities
in a two-step CRC screening strategy. Although colonoscopy
remains the gold-standard test for CRC, access, availability
and the potential for harm continue to hinder its widespread
acceptance as an upfront population screening tool.
Five-year view
Countries that had introduced CRC screening decades ago are
now observing a trend of reduced CRC incidence and mortality.
CRC screening is also gaining momentum in many countries
and it is envisaged that in 5 years time, the number of subjects
being screened worldwide will be greatly increased. We hope
to see the favorable impact of reduced CRC incidence and
mortality worldwide in the next 20–30 years. In addition, as
emerging technologies and screening methods boast of ever-
increasing efficacy, it is important to note that they will be only
as good as the patient actually undergoing the test and, therefore,
patient education and optimization of patient adherence to
screening should be an integral part of any population-based
CRC screening strategy.
Key issues
• The incidence of colorectal cancer (CRC) is increasing worldwide and its economic burden is huge. It is estimated that in 2006, CRC
cancer care cost US$12.1 billon in the USA. CRC screening is one of the ways to contain this spiraling cost.
• There are currently several CRC screening modalities available and these are either stool-based (guaiac-based fecal occult blood test
[gFOBT], fecal immunological test and fecal DNA test) or structural examinations (colonoscopy, sigmoidoscopy, computed tomography
[CT] colonography and colonic capsule endoscopy).
• gFOBT is the oldest available stool-based CRC screening test and has been shown to reduce CRC incidence and mortality in a two-step
approach to CRC screening. Fecal immunological test has demonstrated better performance than gFOBT and is likely to supersede
gFOBT as the first-choice stool-based screening modality.
• Colonoscopy is the only one-step approach to CRC screening. It is also the ‘gold standard’ with which other screening modalities are
compared.
• There is increasing evidence that flexible sigmoidoscopy is highly effective in CRC screening, with reduced CRC incidence and mortality
noted in two randomized controlled trials. This effect is particularly observed for distal lesions, while only a modest effect was noted
for proximal CRCs.
• CT colonography is highly accurate in detecting CRC and large polyps over 10 mm in size; however, its performance decreases with
smaller polyps and there is still controversy in the management of lesions <5 mm in size detected on CT colonography.
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Expert Rev. Gastroenterol. Hepatol. 6(3), (2012)
308
Review Lee, Leen, O’Morain & McNamara
References
1 Ferlay J, Parkin DM, Steliarova-Foucher E.
Estimates of cancer incidence and mortality
in Europe in 2008. Eur. J. Cancer 46(4),
765–781 (2010).
2 Jemal A, Siegel R, Xu J, Ward E. Cancer
statistics, 2010. CA Cancer J. Clin. 60(5),
277–300 (2010).
3 Everhart JE, Ruhl CE. Burden of digestive
diseases in the United States part II: lower
gastrointestinal diseases. Gastroenterology
136(3), 741–754 (2009).
4 Jemal A, Center MM, DeSantis C, Ward
EM. Global patterns of cancer incidence
and mortality rates and trends. Cancer
Epidemiol. Biomarkers Prev. 19(8),
1893–1907 (2010).
5 Yabroff KR, Mariotto AB, Feuer E, Brown
ML. Projections of the costs associated
with colorectal cancer care in the United
States, 2000–2020. Health Econ. 17(8),
947–959 (2008).
6 Hewitson P, Glasziou P, Watson E, Towler
B, Irwig L. Cochrane systematic review of
colorectal cancer screening using the fecal
occult blood test (hemoccult): an update.
Am. J. Gastroenterol. 103 (6 ), 15 41–1549
(2008).
7 Wilson JMG, Jungner G. Principles and
Practice of Screening for Disease. World
Health Organisation, Geneva, Switzerland
(1968).
8 Provenzale D. Cost–effectiveness of
screening the average-risk population for
colorectal cancer. Gastrointest. Endosc. Clin.
N. Am. 12(1), 93–109 (2002).
9 Levin B, Lieberman DA, McFarland B
et al.; American Cancer Society Colorectal
Cancer Advisory Group;US Multi-Society
Task Force;American College of Radiology
Colon Cancer Committee. Screening and
surveillance for the early detection of
colorectal cancer and adenomatous polyps,
2008: a joint guideline from the American
Cancer Society, the US Multi-Society Task
Force on Colorectal Cancer, and the
American College of Radiology.
Gastroenterology 13 4(5) , 1570 –1595
(2008).
10 Ahlquist DA, Sargent DJ, Loprinzi CL
et al. Stool DNA and occult blood testing
for screen detection of colorectal neoplasia.
Ann. Intern. Med. 149(7), 441–450, W81
(2008).
11 Itzkowitz S, Brand R, Jandorf L et al.
A simplified, noninvasive stool DNA test
for colorectal cancer detection. Am. J.
Gastroenterol. 103(11), 2862–2870 (2008).
12 Gellad ZF, Provenzale D. Colorectal
cancer: national and international
perspective on the burden of disease and
public health impact. Gastroenterology
138 (6), 2177–2190 (2010) .
13 Allison JE. Review article: faecal occult
blood testing for colorectal cancer. Aliment.
Pharmacol. Ther. 12(1), 1–10 (1998).
14 Selinger RR, Norman S, Dominitz JA.
Failure of health care professionals to
interpret fecal occult blood tests accurately.
Am. J. Med. 114(1), 64–67 (2003).
15 Feinberg EJ, Steinberg WM, Banks BL,
Henry JP. How long to abstain from eating
red meat before fecal occult blood tests.
Ann. Intern. Med. 113(5), 403 –404 (1990).
16 Sinatra MA, St John DJ, Young GP.
Interference of plant peroxidases with
guaiac-based fecal occult blood tests is
avoidable. Clin. Chem. 45(1), 123–126
(1999).
17 Rozen P, Knaani J, Samuel Z. Eliminating
the need for dietary restrictions when using
a sensitive guaiac fecal occult blood test.
Dig. Dis. Sci. 44(4), 756–760 (1999).
18 Clarke P, Jack F, Carey FA, Steele RJ.
Medications with anticoagulant properties
increase the likelihood of a negative
colonoscopy in faecal occult blood test
population screening. Colorectal Dis. 8(5),
389–392 (2006).
19 Rabeneck L, Zwaal C, Goodman JH, Mai
V, Zamkanei M. Cancer Care Ontario
guaiac fecal occult blood test (FOBT)
laboratory standards: evidentiary base and
recommendations. Clin. Biochem.
41(16–17), 1289–1305 (2008).
20 Rennert G, Rennert HS, Miron E,
Peterburg Y. Population colorectal cancer
screening with fecal occult blood test.
Cancer Epidemiol. Biomarkers Prev. 10(11),
1165 –116 8 (20 01) .
21 Lieberman D. Progress and challenges in
colorectal cancer screening and
surveillance. Gastroenterology 138(6),
2115–2126 (2010).
22 Allison JE. Screening for colorectal cancer
2003: is there still a role for the FOBT?.
Tech. Gastrointes. Endos. 5(3), 127–133
(2003).
23 Young GP, St John DJ, Winawer SJ,
Rozen P; WHO (World Health
Organization) and OMED (World
Organization for Digestive Endoscopy).
Choice of fecal occult blood tests for
colorectal cancer screening:
recommendations based on performance
characteristics in population studies: a
WHO (World Health Organization) and
OMED (World Organization for Digestive
Endoscopy) report. Am. J. Gastroenterol.
97(10), 2499–2507 (2002).
24 Fraser CG. Faecal occult blood tests
– eliminate, enhance or update? Ann. Clin.
Biochem. 45(Pt 2), 117–121 (2008).
25 Fu WP, Kam MH, Ling WM, Ong SF,
Suzannah N, Eu KW. Screening for
colorectal cancer using a quantitative
immunochemical faecal occult blood test:
a feasibility study in an Asian population.
Tech. Coloproctol. 13(3), 225–230 (2009).
26 Grazzini G, Visioli CB, Zorzi M et al.
Immunochemical faecal occult blood test:
number of samples and positivity cutoff.
What is the best strategy for colorectal
cancer screening? Br. J. Cancer 100(2),
259–265 (2009).
27 Guittet L, Bouvier V, Mariotte N et al.
Comparison of a guaiac and an
immunochemical faecal occult blood test
for the detection of colonic lesions
according to lesion type and location. Br. J.
Cancer 100(8), 1230–1235 (2009).
28 Hol L, Wilschut JA, van Ballegooijen M
et al. Screening for colorectal cancer:
random comparison of guaiac and
immunochemical faecal occult blood
testing at different cut-off levels. Br. J.
Cancer 100 (7), 1103 –1110 (200 9).
29 Hol L, van Leerdam ME, van Ballegooijen
M et al. Screening for colorectal cancer:
randomised trial comparing guaiac-based
and immunochemical faecal occult blood
testing and flexible sigmoidoscopy. Gut
59(1), 62–68 (2010).
30 Guittet L, Guillaume E, Levillain R et al.
Analytical comparison of three quantitative
immunochemical fecal occult blood tests
for colorectal cancer screening. Cancer
Epidemiol. Biomarkers Prev. 20(7),
1492–1501 (2011).
31 Lee CS, O’Gorman P, Walsh P et al.
Immunochemical faecal occult blood tests
have superior stability and analytical
performance characteristics over guaiac-
based tests in a controlled in vitro study.
J. Clin. Pathol. 64(6), 524–528 (2011).
32 Grazzini G, Ventura L, Zappa M et al.
Influence of seasonal variations in ambient
temperatures on performance of
immunochemical faecal occult blood test
for colorectal cancer screening:
observational study from the Florence
district. Gut 59(11) , 1511–1155 ( 2010) .
33 Parra-Blanco A, Gimeno-García AZ,
Quintero E et al. Diagnostic accuracy of
immunochemical versus guaiac faecal
occult blood tests for colorectal cancer
Expert Review of Gastroenterology & Hepatology Downloaded from informahealthcare.com by 223.82.15.88 on 05/20/14
For personal use only.
309
www.expert-reviews.com
Screening for colorectal cancer Review
screening. J. Gastroenterol. 45(7), 703–712
(2010).
34 Oort FA, Terhaar Sive Droste JS, Van Der
Hulst RW et al. Colonoscopy-controlled
intra-individual comparisons to screen
relevant neoplasia: faecal immunochemical
test vs. guaiac-based faecal occult blood
test. Aliment. Pharmacol. Ther. 31(3),
432–439 (2010).
35 Allison JE, Sakoda LC, Levin TR et al.
Screening for colorectal neoplasms with
new fecal occult blood tests: update on
performance characteristics. J. Natl Cancer
Inst. 9 9(19), 1462–1470 ( 20 07).
36 Levi Z, Rozen P, Hazazi R et al. A
quantitative immunochemical fecal occult
blood test for colorectal neoplasia. Ann.
Intern. Med. 146(4), 244–255 (2007).
37 Smith A, Young GP, Cole SR, Bampton P.
Comparison of a brush-sampling fecal
immunochemical test for hemoglobin
with a sensitive guaiac-based fecal occult
blood test in detection of colorectal
neoplasia. Cancer 107(9 ), 2152–2159
(2006).
38 Morikawa T, Kato J, Yamaji Y, Wada R,
Mitsushima T, Shiratori Y. A comparison
of the immunochemical fecal occult blood
test and total colonoscopy in the
asymptomatic population. Gastroenterology
129(2), 422–428 (2005).
39 Winawer SJ, Zauber AG, Ho MN et al.
Prevention of colorectal cancer by
colonoscopic polypectomy. The National
Polyp Study Workgroup. N. Engl. J. Med.
329(27), 1977–1981 (1993).
40 Müller AD, Sonnenberg A. Prevention of
colorectal cancer by flexible endoscopy and
polypectomy. A case–control study of
32,702 veterans. Ann. Intern. Med.
123(12), 904–910 (1995).
41 Rim SH, Joseph DA, Steele CB, Thompson
TD, Seeff LC; Centers for Disease Control
and Prevention (CDC). Colorectal cancer
screening~United States, 2002, 2004,
2006, and 2008. MMWR Surveill. Summ.
60(Suppl.), 42–46 (2011).
42 Singh H, Penfold RB, DeCoster C et al.
Colonoscopy and its complications across a
Canadian regional health authority.
Gastrointest. Endosc. 69(3 Pt 2), 665– 671
(2009).
43 Levin TR, Zhao W, Conell C et al.
Complications of colonoscopy in an
integrated health care delivery system. Ann.
Intern. Med. 145(12), 880–886 (2006).
44 Regula J, Rupinski M, Kraszewska E et al.
Colonoscopy in colorectal-cancer screening
for detection of advanced neoplasia.
N. Engl. J. Med. 355(18), 1863 –1872
(2006).
45 Khalid-de Bakker CA, Jonkers DM,
Hameeteman W, de Ridder RJ, Masclee
AA, Stockbrügger RW. Cardiopulmonary
events during primary colonoscopy
screening in an average risk population.
Neth. J. Med. 69(4), 186–191 (2011).
46 Bretthauer M, Thiis-Evensen E, Huppertz-
Hauss G et al. NORCCAP (Norwegian
colorectal cancer prevention): a
randomised trial to assess the safety and
efficacy of carbon dioxide versus air
insufflation in colonoscopy. Gut 50(5),
604–607 (2002).
47 Singh H, Nugent Z, Mahmud SM, Demers
AA, Bernstein CN. Predictors of colorectal
cancer after negative colonoscopy: a
population-based study. Am. J. Gastroenterol.
105(3), 663–673; quiz 674 (2010).
48 Petersen BT. Quality assurance for
endoscopists. Best Pract. Res. Clin.
Gastroenterol. 25(3), 349–360 (2011).
49 Kaminski MF, Regula J, Kraszewska E
et al. Quality indicators for colonoscopy
and the risk of interval cancer. N. Engl. J.
Med. 362(19), 1795 –1803 (2010).
50 Rex DK, Cutler CS, Lemmel GT et al.
Colonoscopic miss rates of adenomas
determined by back-to-back colonoscopies.
Gastroenterology 112(1), 24–28 (1997).
51 Pickhardt PJ, Nugent PA, Mysliwiec PA,
Choi JR, Schindler WR. Location of
adenomas missed by optical colonoscopy.
Ann. Intern. Med. 141(5), 352–359
(2004).
52 Bressler B, Paszat LF, Vinden C, Li C, He
J, Rabeneck L. Colonoscopic miss rates for
right-sided colon cancer: a population-
based analysis. Gastroenterology 127(2),
452– 456 (2004 ).
53 Kahi CJ, Imperiale TF, Juliar BE, Rex DK.
Effect of screening colonoscopy on
colorectal cancer incidence and mortality.
Clin. Gastroenterol. Hepatol. 7(7),
770–775; quiz 711 (2009).
54 Brenner H, Chang-Claude J, Seiler CM,
Rickert A, Hoffmeister M. Protection from
colorectal cancer after colonoscopy: a
population-based, case–control study. Ann.
Intern. Med. 154(1), 22–30 (2011).
55 Baxter NN, Goldwasser MA, Paszat LF,
Saskin R, Urbach DR, Rabeneck L.
Association of colonoscopy and death from
colorectal cancer. Ann. Intern. Med. 150(1),
1–8 (2009).
56 Levin TR, Palitz A, Grossman S et al.
Predicting advanced proximal colonic
neoplasia with screening sigmoidoscopy.
JAMA 281(17), 1611–1617 (1999).
57 Atkin WS, Cuzick J, Northover JM,
Whynes DK. Prevention of colorectal
cancer by once-only sigmoidoscopy. Lancet
341(8847), 736–740 (1993).
58 Meza R, Jeon J, Renehan AG, Luebeck EG.
Colorectal cancer incidence trends in the
United States and United kingdom:
evidence of right- to left-sided biological
gradients with implications for screening.
Cancer Res. 70(13), 5419–5429 (2010).
59 Maule WF. Screening for colorectal cancer
by nurse endoscopists. N. Engl. J. Med.
330 (3), 183 –187 (1994).
60 Atkin WS, Cook CF, Cuzick J, Edwards R,
Northover JM, Wardle J; UK Flexible
Sigmoidoscopy Screening Trial
Investigators. Single flexible sigmoidoscopy
screening to prevent colorectal cancer:
baseline findings of a UK multicentre
randomised trial. Lancet 359(9314),
1291–1300 (2002).
61 Imperiale TF, Wagner DR, Lin CY, Larkin
GN, Rogge JD, Ransohoff DF. Risk of
advanced proximal neoplasms in
asymptomatic adults according to the distal
colorectal findings. N. Engl. J. Med.
343(3), 169–174 (2000).
62 Lieberman DA, Weiss DG, Bond JH,
Ahnen DJ, Garewal H, Chejfec G. Use of
colonoscopy to screen asymptomatic adults
for colorectal cancer. Veterans Affairs
Cooperative Study Group 380. N. Engl. J.
Med. 343(3), 162–168 (2000).
63 Schoenfeld P, Cash B, Flood A et al.;
CONCeRN Study Investigators.
Colonoscopic screening of average-risk
women for colorectal neoplasia. N. Engl. J.
Med. 352(20), 2061–2068 (2005).
64 Atkin WS, Edwards R, Kralj-Hans I et al.
Once-only flexible sigmoidoscopy
screening in prevention of colorectal
cancer: a multicentre randomised
controlled trial. Lancet 375(9726),
1624 –1633 (2010).
65 Atkin W, Rogers P, Cardwell C et al.
Wide variation in adenoma detection rates
at screening flexible sigmoidoscopy.
Gastroenterology 126(5), 1247–1256
(2004).
66 Winawer S, Fletcher R, Rex D et al.;
Gastrointestinal Consortium Panel.
Colorectal cancer screening and
surveillance: clinical guidelines and
rationale–update based on new evidence.
Gastroenterology 124(2), 544–560 (2003).
67 Graser A, Stieber P, Nagel D et al.
Comparison of CT colonography,
Expert Review of Gastroenterology & Hepatology Downloaded from informahealthcare.com by 223.82.15.88 on 05/20/14
For personal use only.
Expert Rev. Gastroenterol. Hepatol. 6(3), (2012)
310
Review Lee, Leen, O’Morain & McNamara
colonoscopy, sigmoidoscopy and faecal
occult blood tests for the detection of
advanced adenoma in an average risk
population. Gut 58(2), 241–248 (2009).
68 Hoff G, Grotmol T, Skovlund E,
Bretthauer M; Norwegian Colorectal
Cancer Prevention Study Group. Risk of
colorectal cancer seven years after flexible
sigmoidoscopy screening: randomised
controlled trial. BMJ 338, b1846 (2009).
69 Segnan N, Armaroli P, Bonelli L et al.;
SCORE Working Group. Once-only
sigmoidoscopy in colorectal cancer
screening: follow-up findings of the
Italian Randomized Controlled Trial–
SCORE. J. Natl Cancer Inst. 103 (17),
1310–1322 (2011).
70 Pickhardt PJ. Incidence of colonic
perforation at CT colonography: review
of existing data and implications for
screening of asymptomatic adults.
Radiology 239 (2), 313 –316 (2006).
71 Macari M, Bini EJ. CT colonography:
where have we been and where are we
going? Radiology 237(3), 819–833 (2005).
72 Pickhardt PJ, Choi JR, Hwang I et al.
Computed tomographic virtual
colonoscopy to screen for colorectal
neoplasia in asymptomatic adults.
N. Engl. J. Med. 349(23), 2191–2200
(2003).
73 Pickhardt PJ, Hassan C, Halligan S,
Marmo R. Colorectal cancer: CT
colonography and colonoscopy for
detection–systematic review and
meta-analysis. Radiology 259(2), 393 –405
(2 011) .
74 Johnson CD, Chen MH, Toledano AY
et al. Accuracy of CT colonography for
detection of large adenomas and cancers.
N. Engl. J. Med. 359(12), 1207–1217
(2008).
75 Rex DK, Overhiser AJ, Chen SC,
Cummings OW, Ulbright TM.
Estimation of impact of American College
of Radiology recommendations on CT
colonography reporting for resection of
high-risk adenoma findings.
Am. J. Gastroenterol. 104(1), 149–153
(2009).
76 Lieberman D, Moravec M, Holub J,
Michaels L, Eisen G. Polyp size and
advanced histology in patients undergoing
colonoscopy screening: implications for
CT colonography. Gastroenterology
135(4), 1100–1105 (2008).
77 Yee J, Kumar NN, Godara S et al.
Extracolonic abnormalities discovered
incidentally at CT colonography in a male
population. Radiology 236(2), 519–526
(2005).
78 Sutherland T, Coyle E, Lui B, Lee WK.
Extracolonic findings at CT colonography:
a review of 258 consecutive cases. J. Med.
Imaging Radiat. Oncol. 55(2 ), 149–152
(2 011) .
79 Gluecker TM, Johnson CD, Wilson LA
et al. Extracolonic findings at CT
colonography: evaluation of prevalence and
cost in a screening population.
Gastroenterology 124(4 ), 911–916 (2003).
80 Flicek KT, Hara AK, Silva AC, Wu Q,
Peter MB, Johnson CD. Reducing the
radiation dose for CT colonography using
adaptive statistical iterative
reconstruction: a pilot study. AJR Am. J.
Roentgenol. 195(1), 126–131 (2010).
81 Frazier AL, Colditz GA, Fuchs CS, Kuntz
KM. Cost–effectiveness of screening for
colorectal cancer in the general
population. JAMA 284 (15), 1954 –1961
(2000).
82 Pignone M, Saha S, Hoerger T,
Mandelblatt J. Cost–effectiveness analyses
of colorectal cancer screening: a systematic
review for the U.S. Preventive Services Task
Force. Ann. Intern. Med. 137(2), 96–104
(2002).
83 vanRossum LG, van Rijn AF, Verbeek AL
et al. Colorectal cancer screening
comparing no screening, immunochemical
and guaiac faecal occult blood tests: a
cost–effectiveness analysis. Int. J. Cancer
128( 8), 19 08 –1917 (2011).
84 Whynes DK; Nottingham FOB Screening
Trial. Cost–effectiveness of screening for
colorectal cancer: evidence from the
Nottingham faecal occult blood trial.
J. Med. Screen. 11(1), 11–15 (2004).
85 Chen LS, Liao CS, Chang SH, Lai HC,
Chen TH. Cost–effectiveness analysis for
determining optimal cut-off of
immunochemical faecal occult blood test
for population-based colorectal cancer
screening (KCIS 16). J. Med. Screen. 14(4),
191–199 ( 20 07 ).
86 Lee D, Muston D, Sweet A, Cunningham
C, Slater A, Lock K. Cost effectiveness of
CT colonography for UK NHS colorectal
cancer screening of asymptomatic adults
aged 60–69 years. Appl. Health Econ.
Health Policy 8(3), 141–154 (2010).
87 Hassan C, Benamouzig R, Spada C et al.
Cost effectiveness and projected national
impact of colorectal cancer screening in
France. Endoscopy 43(9), 780–793
(2 011) .
88 Zauber AG. Cost–effectiveness of
colonoscopy. Gastrointest. Endosc. Clin. N.
Am. 20(4), 751–770 (2010).
89 Tappenden P, Chilcott J, Eggington S,
Patnick J, Sakai H, Karnon J. Option
appraisal of population-based colorectal
cancer screening programmes in England.
Gut 56(5), 677–684 (2007).
90 Wong SS, Leong AP, Leong TY.
Cost–effectiveness analysis of colorectal
cancer screening strategies in Singapore: a
dynamic decision analytic approach. Stud.
Health Technol. Inform. 107(Pt 1), 104 –110
(2004).
91 Knudsen AB, Lansdorp-Vogelaar I, Rutter
CM et al. Cost–effectiveness of computed
tomographic colonography screening for
colorectal cancer in the medicare
population. J. Natl Cancer Inst. 102(16),
1238–1252 (2010).
92 Health Information and Quality Authority.
Health technology assessment (HTA) of a
population-based colorectal cancer screening
programme in Ireland. HIQA, Cork,
Ireland (2009).
93 Edwards BK, Ward E, Kohler BA et al.
Annual report to the nation on the status of
cancer, 1975–2006, featuring colorectal
cancer trends and impact of interventions
(risk factors, screening, and treatment) to
reduce future rates. Cancer 116 (3 ),
544–573 (2010).
94 Whitlock EP, Lin JS, Liles E, Beil TL, Fu
R. Screening for colorectal cancer: a
targeted, updated systematic review for the
U.S. Preventive Services Task Force. Ann.
Intern. Med. 149(9), 638–658 (2008).
95 McNamara D, Qasim A, Lee N, Condon
C, O’Morain C. Round one of the Adelaide
and Meath Hospital/Trinity College
Colorectal Cancer Screening Programme:
programme report and analysis based on
established international key performance
indices. Ir. J. Med. Sci. 180(2), 549–552
(2 011) .
96 Spada C, Hassan C, Munoz-Navas M et al.
Second-generation colon capsule
endoscopy compared with colonoscopy.
Gastrointest. Endosc. 74(3), 581–589.e1
(2 011) .
97 Young GP, Bosch LJ. Fecal tests: from
blood to molecular markers. Curr.
Colorectal Cancer Rep. 7(1), 62 –70 (2011).
98 Burch JA, Soares-Weiser K, St John DJ
et al. Diagnostic accuracy of faecal occult
blood tests used in screening for colorectal
cancer: a systematic review. J. Med. Screen.
14(3), 132–137 (2007).
Expert Review of Gastroenterology & Hepatology Downloaded from informahealthcare.com by 223.82.15.88 on 05/20/14
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311
www.expert-reviews.com
Screening for colorectal cancer Review
99 Pickhardt PJ, Hassan C, Laghi A et al.
Small and diminutive polyps detected at
screening CT colonography: a decision
analysis for referral to colonoscopy. AJR
Am. J. Roentgenol. 190(1), 136–144 (2008).
100 Heitman SJ, Hilsden RJ, Au F, Dowden S,
Manns BJ. Colorectal cancer screening for
average-risk North Americans: an
economic evaluation. PLoS Med. 7(11),
e1000370 (2010).
Websites
201 National Cancer Institute. Cancer Trends
Progress Report – 2009/2010 Update
(2010).
http://progressreport.cancer.gov
202 Colorectal Cancer Screening in Average-
risk Population: Immunochemical Fecal
Occult Blood Testing Versus
Colonoscopy.
http://clinicaltrials.gov/ct2/show/
NCT00906997
203 The Northern-European Initiative on
Colorectal Cancer (NordICC).
http://clinicaltrials.gov/ct2/show/
NCT00883792
204 National Cancer Screening Service.
Recommendations for a Colorectal
Cancer Screening Programme in Ireland
(2008).
www.cancerscreening.ie/publications/
Colorectal-Recommendations.pdf
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312
Review Lee, Leen, O’Morain & McNamara
Screening for colorectal cancer: what fits best?
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1. You are considering starting a colorectal cancer (CRC) screening program in your health maintenance organization
(HMO). Based on the review by Dr. Lee and colleagues, which of the following statements about stool-based
modalities available for CRC screening is most likely correct?
£AStool tests are sufficient for complete CRC screening
£BGuaiac fecal occult blood tests (gFOBT) and fecal immunochemical tests (FIT) detect very early stage colorectal
neoplasia and cancer
£CA genetic stool DNA test is widely available and highly accurate
£DFIT has better diagnostic performance than gFOBT
2. Based on the review by Dr. Lee and colleagues, which of the following statements about structural examinations
available for CRC screening is most likely correct?
£AColonoscopy is the only 1-step approach to CRC screening, and it is the “gold standard” for other screening
modalities
£BFlexible sigmoidoscopy is highly effective in detecting proximal CRCs
£CCT colonography is highly accurate in detecting CRC and polyps over 5 mm in size
£DThe management of lesions <5 mm detected on CT colonography is well established
3. Based on the review by Dr. Lee and colleagues, which of the following statements about overall principles
regarding CRC screening would most likely be correct?
£AThere is no evidence that screening programs reduce CRC mortality or incidence
£BThe screening test of choice is clearly determined
£CFor a population-based CRC screening program, it is best to have multiple CRC screening strategies
£DFIT is one of the best strategies currently available for a population-based CRC screening program, but this may
change with advancing technology and changes in CRC epidemiology
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