Content uploaded by Christopher B Umbricht
Author content
All content in this area was uploaded by Christopher B Umbricht on Aug 21, 2018
Content may be subject to copyright.
ORIGINAL STUDY
MicroRNA Expression and Association
with Clinicopathologic Features in Papillary Thyroid Cancer:
A Systematic Review
Patricia Aragon Han,
1
Chien-Hsiang Weng,
1
Hunain T. Khawaja,
1
Neeraja Nagarajan,
2
Eric B. Schneider,
2
Christopher B. Umbricht,
1
Kenneth W. Witwer,
3
and Martha A. Zeiger
1
Background: Studies have suggested that microRNAs (miR) may be useful prognostic markers and are as-
sociated with aggressive clinicopathologic features in papillary thyroid cancer (PTC). This systematic review
examined associations between miRs and aggressive clinicopathologic features in PTC.
Methods: A literature search was performed within the PubMed, Embase, Cochrane, Web of Science, and
Scopus databases for papers published prior to November 24, 2014. The search was performed by combining
the concepts ‘‘thyroid tumor’’ with ‘‘microRNA’’ and by using ‘‘and’’ as the Boolean operator. Upon retrieval
of candidate studies, full-text publications were reviewed in their entirety and selected if they examined the
prognostic significance between miR expression and established aggressive clinicopathologic features of PTC.
Results: Fifteen studies from 13 unique groups that included 807 patients were reviewed. Most of the studies
were retrospective, and none included patients who had undergone routine central lymph node dissection.
Expression levels of miRs-21, -34b, -130b, -135b, -146b, -151, -181b, -199b-5p, -221, -222, -451, -623,
-1271, -2861, and let-7e showed significant association with at least one aggressive feature, such as large
tumor size, extrathyroidal extension, multifocality, lymphovascular invasion, lymph node metastases, distant
metastasis, advanced American Joint Cancer Committee stage, and presence of the BRAF
V600E
mutation. Herein
we summarize the literature with regard to these associations.
Conclusion: Further studies are needed to investigate whether miRs are independent predictors of aggressive
clinicopathologic features before it can be recommended that miR expression levels should be incorporated into
the management algorithm for patients with PTC. A well-designed prospective study is needed to assess these
potential associations.
Introduction
Papillary thyroid cancer (PTC) is the most common
type of differentiated thyroid cancer, comprising 65–
88% of thyroid cancers (1). Although >90% of patients ex-
perience excellent five-year survival rates when treated with
appropriate surgical and medical therapy (2), 5–10% expe-
rience a more aggressive clinical course, characterized by
early metastases, increased mortality, resistance to radioac-
tive iodine, and disease recurrence (3).
Aggressive clinicopathologic features of PTC such as
tumor size >2 cm, multifocality, extrathyroidal extension
(ETE), lymphovascular invasion (LVI), lymph node metas-
tasis (LNM), distant metastases, and histological variants
such as tall-cell or columnar types determine treatment op-
tions and play key roles in patient outcome. However, often
these clinicopathologic features are unknown preoperatively
and are thus unavailable to guide precise surgical manage-
ment, including the determination of whether a patient
should undergo a prophylactic central lymph node dissection
(CLND) (4–7).
The recent expansion of knowledge and efforts to geneti-
cally characterize PTCs by The Cancer Genome Atlas Re-
search Network (TCGA) Thyroid Working Group and others
have revealed that microRNAs (miR) may play an important
role in PTC prognosis (8–19). miR are small nonprotein-
coding RNA molecules that are 21–25 nucleotides in length.
They regulate gene expression at the post-transcriptional le-
vel by binding to imperfectly complementary sequences
within target miRs (often in the 3¢-untranslated regions),
thereby leading to degradation or translational suppression
(20). Previous studies have reported that specific miRs
are associated with aggressive clinicopathologic features
of PTC, such as those listed above in addition to BRAF
1
Endocrine Surgery Section, Department of Surgery;
2
Johns Hopkins Surgery Center for Outcomes Research, Department of Surgery;
3
Department of Molecular and Comparative Pathobiology; The Johns Hopkins University School of Medicine, Baltimore, Maryland.
THYROID
Volume X, Number X, 2015
ªMary Ann Liebert, Inc.
DOI: 10.1089/thy.2015.0193
1
mutation. However, other studies have failed to report any
significant association (9–18,21–25).
Despite the inconclusive studies in the literature, the in-
corporation of specific miR expression panels into the sur-
gical management algorithm of PTC in order to improve
perioperative decision making has been suggested (9–18,21–
25). To the authors’ knowledge, however, there is no pub-
lished systematic review examining the clinicopathologic
significance of miRs in PTCs. Therefore, a systematic review
of the literature was conducted to examine the associations
between expression levels of certain miRs and aggressive
clinicopathologic features in PTC.
Materials and Methods
All aspects of the Cochrane Handbook for Interventional
Systematic Reviews (26) were followed. The study was
written in accordance with the guidelines proposed by the
preferred reporting items for systematic review and meta-
analyses (PRISMA) statement (27). Papers published prior to
November 24, 2014, were searched on PUBMED, EMBASE,
Cochrane, Web of Science, and Scopus databases by com-
bining the terms ‘‘thyroid tumor’’ with ‘‘microRNA’’ by
using ‘‘AND’’ as the Boolean operator (see Supplementary
Data; Supplementary Data are available online at www
.liebertpub.com/thy).
Three reviewers (P.A.H., C.H.W., and H.T.K.), working
independently and in three teams of two, used web-based
standardized forms and screened all abstracts and titles for
miR expression in PTC. Upon retrieval of candidate studies,
full-text publications were reviewed in their entirety and
selected if they examined the prognostic significance be-
tween miR expression and any clinicopathologic features
of PTC. Specific clinical features included patient sex, age,
tumor size, histological subtype of PTC, multifocality, cap-
sular invasion, LVI, ETE, LNM, distant metastasis, stage of
disease (American Joint Cancer Committee; AJCC), and
BRAF
V600E
mutation status.
Exclusion criteria included the following: review articles,
single case reports, letters to the editor, abstracts presented in
conferences, studies using miRs for differentiation between
benign and malignant thyroid lesions, studies examining miR
target genes, and studies of in vitro models. In instances
where the same study cohort was used in multiple articles
reporting different miRs, only the study based upon the
largest patient population was included in the total patient
count (11,12,17,18). The reviewers also independently as-
sessed citations of relevant articles to identify additional
studies for inclusion. At each stage of the selection process,
discrepancies in article selection between two reviewers were
discussed by the study team members and resolved. Re-
viewers also extracted methodological and outcome data
from all eligible studies.
Results
Figure 1 describes the flow of candidate and eligible arti-
cles. After removing duplicates, a total of 830 abstracts were
identified, of which 174 by title and abstract alone were
deemed relevant. Of the 174 full-text articles evaluated
FIG. 1. Preferred reporting
items for systematic review
and meta-analyses (PRIS-
MA) flow chart: algorithm
for identification of eligible
studies with inclusion and
exclusion criteria.
2 ARAGON HAN ET AL.
against the predetermined inclusion criteria described above,
48 articles met the initial eligibility criteria. Of these, 33
articles were excluded because they were in vitro studies or
studies using miRs for diagnosis only. The remaining 15
studies were systematically reviewed and abstracted.
Design of the studies
Table 1 summarizes the results of the 15 studies com-
prising 807 patients (9–15,17,18,21–25,28). The earliest
study was published in April 2009 (23), and the latest in
August 2014 (14). The largest study evaluating miR ex-
pression from tissue samples included 100 patients (18); only
one study evaluated circulating serum miR and included 106
patients (25). The smallest study evaluating miR expression
in tissue samples included 30 patients (15). Two studies were
prospective (17,25). None of the studies included patients
who had undergone prophylactic lymph node dissection.
For initial biomarker screening, eight studies performed
miR microarray (10–12,14,15,21,22,28), and one performed
Solexa RNA sequencing (25) followed by quantitative poly-
merase chain reaction (q-PCR) to validate the results. Con-
versely, six studies identified candidate miRs from the
literature and performed q-PCR (13,17,18,23,24) or Northern
blots (9) to characterize miR expression. Four studies evalu-
ated miR expression in formalin-fixed paraffin-embedded
(FFPE) tissue (13,15,21,23), whereas seven used fresh frozen
tissue (11,12,14,17,18,24,28), three used a combination of
FFPE and frozen (9,10,22), and only one examined serum (25).
The 15 studies utilized a variety of statistical methods to
analyze their outcomes (Supplementary Table S1). A number
of studies (9–12,15,17,21,24,25) compared the mean of miR
expression using Student’s t-test, a parametric test for testing
differences in mean between groups. In studies where the
assumptions for using parametric tests were not met (9–
13,15,17,18,22–25), Kruskal–Wallis, Mann–Whitney U,or
Wilcoxon rank sum tests were used to compare continuous
values of miR. Eight studies (10,13–15,21,22,25,28) also
utilized parametric and nonparametric tests to compare other
continuous variables. The correlation between different miRs
was tested in three studies (21,24,25) by using Pearson’s
correlation coefficient. Differences between groups for cate-
gorical variables were analyzed utilizing Pearson’s chi-square
test in multiple studies (9,12,13,15,17,22,23). Specifically,
this was often used for comparing BRAF mutation status
between groups. Only one study performed both univariate
and multivariable logistic regression to identify independent
clinicopathologic features and molecular markers for prog-
nosis (17). Disease-free survival was analyzed in two studies,
which utilized Kaplan–Meyer graphs, log–rank test, and
Cox proportional hazards models (17,22). None of the studies
examined addressed the positive predictive value (PPV)
or negative predictive value (NPV) of miRs in their analyses
(9–15,17,18,21–25,28).
The risk of bias in the included studies was assessed using
a modified Newcastle–Ottawa Scale (NOS) for observational
studies (29). The NOS includes a set of questions, or scale,
consisting of eight multiple-choice questions that address
subject selection and comparability (of cases and controls in
case-control studies, of cohorts in cohort studies) and the
assessment of the outcome (in case-control studies) or ex-
posure (in cohort studies). High-quality responses earn a star,
totaling up to nine stars (the comparability question earns up
to two stars) (29,30). In this review, a score was presented
summarizing the number of stars earned by each study in
each domain (Supplementary Table 2). Overall, the studies
were consistently of high quality. However, including pa-
tients with routine CLND would have improved compara-
bility. For the assessment of selection criteria, one study
received two stars (21), while 14 of the 15 studies had four
stars (9–15,17,18,22–25,28). For the assessment of comparabil-
ity of the groups, three studies were given two stars (17,22,25),
while 12 studies received one star (9–15,18,21,23,24,28). All
15 of the included studies scored four stars in the exposure
criteria (9–15,17,18,21–25,28).
miR and aggressive features in PTC
Sex and age. Ten studies, including 644 cases, analyzed
the association between miR expression levels and sex (9,12–
14,17,18,23–25,28), of which two studies reported a signifi-
cant association (12,18). Expression levels of miRs-146b,
-221, and -222 were significantly higher in male patients.
The same 10 studies analyzed the association between miR
expression levels and age (9,12–14,17,18,23–25,28). Only
one study (12) reported age-associated expression changes,
with significantly higher expression of miR-222 in patients
‡45 years of age.
Tumor size, histological subtypes, and multifocality. Ten
studies, including 632 cases, analyzed the association be-
tween miR expression and tumor size (9,12–14,17,18,21,23–
25), of which five studies reported a significant association
(12,13,21,23,25). There was a positive correlation between
larger tumor size and expression levels of miRs-135b, -146b,
-151-5p, -181b, -221, and -222 (12,13,21,23,25). Three
studies (21–23), including 157 cases, analyzed the associa-
tion between miR expression and histological subtypes of
PTC. Higher expression levels of miRs-221, -222, and -623
were associated with classical variant of PTC (CVPTC),
whereas higher expression levels of miRs-125a-3p, -153,
and -1271 were associated with follicular variant of PTC
(FVPTC) (21,22). Furthermore, miRs-146b, -221, and -222
exhibited the highest fold change in tall-cell variant of PTC,
followed by CVPTC and FVPTC (23), whereas miRs -375
and -551b were found to be highly upregulated in FVPTC
(22). Nine studies, including 649 cases, analyzed the asso-
ciation between miR expression and multifocality (9,12,14,
18,21,23–25,28), of which only two reported a significant
association (21,25). Higher expression levels of miR-146b
and let-7e were associated with multifocal PTC (21,25).
Capsular invasion, LVI, and ETE. Only one study (21),
including 57 cases, analyzed the association between miR
expression and capsular invasion, of which miRs-146b, -221,
and -222 were significant (21). Two studies (13,21), in-
cluding 109 cases, analyzed the association between miR
expression and LVI. Only one (21) reported expression levels
of miRs-146b, -221, and -222 to be associated with LVI.
Seven studies, including 326 cases, analyzed the association
between miR expression and ETE (9,12,14,17,18,23,24), of
which five reported a significant association (9,12,14,18,24).
Higher expression levels of miRs-135b, -146b, -199b-5p,
-221, and -222 were associated with ETE (9,12,14,18,24).
MIR AND THYROID CANCER PROGNOSIS 3
Table 1. Summary of miR Expression and Significant Associated Features in PTC
Study n
a
miR Sex Age
Tumor
size
Histological
subtype Multifocality
Capsular
invasion LVI ETE LNM
Distant
metastasis AJCC BRAF(total 807)
1 Peng 2014 36 199b-5p - - - - **
2 Acibucu 2014 57 146b *-*** **-
221 ** -** * * *
222 ** -** * --
3 Chou 2013 71 146b - - - - **-
4 Dettmer 2013 44 125a-3p *
153 *
623 *
1271 *
5 Huang 2013 69 21 - - - *-*
203 - - - - - *
6 Lee 2013 30 146b *
221 *
222 *
7 Sun/Yu 2013 52 21 - - - - - - -
146b - - - - - - *
181b - - *-- -*
221 - - *-***
222 - - - - ***
8 Wang Z 2013 91
b
135b - - *-*-*
146b - - *-*--
221 *-- - *--
222 ** * -*-*
9 Wang Z 2013 87 451 *
2861 *
10 Yu 2012 106 let-7e - - - *---
151-5p - - *-*--
222 - - - - **-
11 Wang P 2012 83 221 - - - - *-- -
222 - - - - *-- -
12 Zhou 2012 51 221 - - - - ** * *
13 Yip 2011 32 34b
b
*-
130b
b
*-
146b **
222 *-
14 Chou 2010 100
b
146b *-- - *-**
221 - - - - *-*-
222 - - - - *---
15 Sheu 2009 56 21 - - - - - - -
146b - - - - - - -
181b - - *--- -
221 - - - - - - -
222 - - - - - - -
miR nomenclature: The prefix ‘‘miR’’ is followed by a dash and a number, the latter often indicating order of naming (e.g., miR-21 was named prior to miR-34); a capitalized ‘‘miR-’’ refers to the
mature form of the miRNA; miRs with nearly identical sequences except for one or two nucleotides are annotated with an additional lower case letter (e.g., miR-146a and miR-146b are closely
related); when two mature miRs originate from opposite arms of the same pre-miR, they are denoted with a -3p or -5p suffix (e.g., miR-146-3p and miR-146-5p).
Studies 3 and 14 and 8 and 9 studied different miRs.
a
The total nincludes the larger number of cases from the two sets of presumably overlapping patients.
b
All miRs were upregulated, except miRs-34b and -130b, which were downregulated. Study #3 performed multivariable logistic regression analysis; study #10 measured circulating serum miRs.
*, statistically significant; -, no association; [blank space], surrogate outcome was not tested.
miR, microRNA; PTC, papillary thyroid carcinoma; LVI, lymphovascular invasion; ETE, extrathyroidal extension; LNM, lymph node metastases; AJCC, American Joint Cancer Committee.
4
Furthermore, higher expression levels of miR-146b were
associated with extensive extrathyroidal invasion in a sub-
group analysis of 25 cases with ETE (12).
LNM and distant metastasis. Eleven studies, including
701 cases, analyzed the association between miR expression
and LNM (9,11–14,17,21,23–25,28), of which eight reported
a significant association (9,11–14,17,21,25,28). Expression
levels of miRs-21, -146b, -151-5p, -199b-5p, -221, -222,
-451, and -2861 were significantly higher in patients with
LNM (9,11–14,17,21,25,28). Furthermore, expression levels
of miRs-451 and -2861 were significantly higher in patients
with lateral LNM (11). Three studies, including 209 cases,
analyzed the association between miR expression and dis-
tant metastasis (17,21,24). Expression levels of miRs-146b
and -221 were significantly higher in cases with distant
metastasis (21).
Tumor staging (AJCC). Nine studies, including 572
cases, analyzed the association between miR expression and
tumor staging (9,10,12,13,17,18,21,24,25), of which seven
reported a significant association (9,10,12,13,17,21,25).
Higher expression levels of miRs-135b, -146b, -221, and -222
were significantly associated with high-risk groups, defined as
patients with AJCC stage III or IV (9,10,12,13,17,21,25).
BRAF
V600E
mutation.Nine studies, including 496 cases,
analyzed the association between miR expression and
BRAF
V600E
mutation status (9,10,13,15,17,18,23,25,28), of
which six reported a significant association (9,10,13,15,
17,28). Expression levels of miRs-21, -146b, -203, -181b,
-221, and -222 were significantly higher in tumors with
BRAF mutation compared with those with wild-type BRAF
gene alleles (9,10,13,15,17,28).
Discussion
This systematic review outlines several miRs that were
shown to be associated with aggressive features of PTC. The
five main publication databases were searched to assure
identification of all relevant publications. To the best of the
authors’ knowledge, this represents the first systematic re-
view of miR association with aggressive features of PTC.
Overall, most studies identified upregulated expression of
miRs-146b, -221, and -222 in association with several ag-
gressive features in PTC. These associations do not necessarily
presuppose a causative role for these miRs in progression, but
it is possible that miR and miR target dysregulation could
represent key molecular events in PTC development and its
progression. One could hypothesize, based upon these find-
ings, that increased expression levels of miRs-146b, -221, and
-222 provide cells with a selective growth advantage, leading
them to develop aggressive features sequentially such as larger
tumor size, ETE, LNM, and advanced AJCC stage. As shown
in Table 2, these latter aggressive features were the most
consistently reported to be associated with miR upregulation.
Older age and male sex are risk factors associated with poorer
thyroid cancer prognosis, but predicting them using miRs is
not meaningful, and they are only listed in the tables as ref-
erence to the primary literature.
These results are consistent with observations that miR-
146b is associated with a risk of recurrence and promotes cell
migration and invasion with expression of cancer-promoting
genes and regulators of apoptosis (8,17). Furthermore, pre-
vious studies have identified that miR-221 and miR-222 are
activated by high-motility group box 1 protein (HMGB1) in
PTCs, and both promote proliferation by inhibiting the
translation of cell cycle regulator p27kip1 (31).
Target genes regulated by miRs-146b, -221, and -222 in
PTC remain under study, and little has been reported regarding
the molecular mechanism by which miRs influence aggressive
features in PTC. MiR-146b is encoded by a gene on chro-
mosome 10q24. Some of the predicted miR-146b-5p targets
include adherens junction and mesenchymal-epithelial tran-
sition (MET) gene sets, which suggests a functional role in
promoting epithelial-mesenchymal transition (EMT). EMT is
an important step in metastasis, and as documented in this
review (Table 2), several studies suggest that miR-146b-5p
may be associated with central LNM. The MiR-221 and miR-
222 genes are clustered on chromosome X, which might
Table 2. Summary of miR Expression and Associated Features in PTC by miR
miR Sex Age
Tumor
size
Histological
subtype Multifocality
Capsular
invasion LVI ETE LNM
Distant
metastasis AJCC BRAF
21 **
34b *
130b *
135b * * *
146b ** * * * ** ** * ** ****
151-5p * *
181b ** *
199b-5p * *
221 * ** * * * **** *** * **** ***
222 * * ** * * * *** **** **** **
451 *
623 *
1271 *
2861 *
let-7e *
Number of asterisks (*) in columns representative of number of studies with a significant association.
All miRs were upregulated except miRs-34b and -130b, which were downregulated.
MIR AND THYROID CANCER PROGNOSIS 5
explain their similar expression pattern and presumed sphere
of influence (Table 2). Some of the predicted miR-221 and
-222 targets include gene sets thatenhance genomic instability
and subsequent cell proliferation. The mechanism by which
they do so includes reducing p27
Kip1
protein expression and
promoting EMT that in turn leads to increased growth rate and
cancer-cell invasiveness (31,32).
While the biological implications of miRs-146b, -221, and
-222 remain under study, recently the TCGA Thyroid
Working Group has proposed putative target genes for miR-
146b, -221, and -222, which include: IRAK1, KIT,TRAF6,
and PDCD4 for miR-146b;and p27
Kip1
for miRs-221 and
-222 (8), findings that are relevant to the present analysis.
Notably, it is apparent in this systematic review that miRs-
146b-5p, -221, and -222 may play a role in BRAF-mutated
PTCs. However, there is also evidence that altered expression
of miR may occur independent of the BRAF
V600E
mutation,
and other (epi)genetic mechanisms might instead be re-
sponsible for their dysregulation (25). BRAF
V600E
is known to
be the most common mutation (up to 80%) found in PTC.
However, its role as an independent predictor marker asso-
ciated with aggressive features, specifically with LNM, is still
controversial (33).
While the overwhelming majority of studies measured
miR expression in tumor tissue, one study measured circu-
lating miR expression in serum. This study demonstrated the
potential of serum let-7e, miR-151-5p, and miR-222 as
markers for prognosis in PTC by showing that circulating
levels of these miRs are detectable both before and after
tumor excision. However, the mechanism underlying the
release of miR from tissues into the bloodstream is unknown,
and it remains unclear whether circulating miR levels can
accurately reflect miR expression in specific tissues (34,35).
Importantly, in the course of conducting this review, a
number of limitations were identified in the included studies
that may explain the differences in reported results. First,
results may be biased because, with the exception of two
studies (17,25), all were retrospective. Second, small num-
bers of patients were analyzed in each study; the largest study
included 106 patients (25), raising questions about achieving
adequate statistical power. Third, the cutoff levels of miR
expression in tumor tissues used to predict prognosis were
not uniform. Fourth, with one exception, none of the studies
included multivariable analysis (17). Lastly, and most im-
portantly, none of the studies included patients who had un-
dergone routine prophylactic central neck dissection.
Performing lymph node dissection only for patients already
suspected to have metastases preoperatively can result in a
biased study outcome, since the lymph node status is only
known for this particular subset of patients.
Because discrepancies exist in the existing literature re-
garding the association of several miRs with aggressive
clinicopathologic features of PTC, the prognostic value of
miRs remains to be established in well-designed future
studies. An ideal prospective study needs to be adequately
powered to detect clinically meaningful differences in the
association between miR levels and each of the aggressive
features described above, including central LNM. Such a
study would require prophylactic CLND in all patients and
would need to be powered to detect relationships between
miR levels and outcomes across all PTC subtypes. It is rec-
ognized that it may be difficult to enroll sufficient numbers of
patients to capture adequate samples of the less common
forms of PTC (e.g., follicular variant or tall-cell PTC).
However, given the fact that the vast majority of the patients
have CVPTC, a study powered to detect meaningful differ-
ences among patients with classical PTC may provide, at a
minimum, genetic insights into common pathways. The
principal improvement in understanding the relationships
between miR levels and outcomes available from a pro-
spective study involves the elimination of selection bias in
CLND. The majority of retrospective studies examined CLN
pathology only in patients who underwent CLND, thus bi-
asing the sample of patients studied toward those with pos-
sibly more aggressive or advanced disease, or because of
surgeon preference.
In addition, PPV and NPV are extremely important factors
in determining the usefulness of any test. It is not possible to
determine the PPV and NPV of miR levels without including
patients who did not undergo CLND. Moreover, PPV and
NPV may be very different across PTC subtypes or in the
presence of certain disease features.
Although definitive studies are currently lacking, miRs
may hold a potential as prognostic indicators in PTC. Mea-
surement of miR expression might facilitate and optimize
surgical management of patients with PTC. Yet, currently,
information is insufficient to guide clinical decision making.
In particular, future development of assays analyzing FNA
samples and validation of these findings regarding miRs in
the preoperative setting will be needed. Further prospective
studies, however, that overcome the aforementioned limita-
tions, including bias in selecting patients for lymph node
dissection, are required before incorporating expression
levels of miRs as predictive markers of aggressive clinico-
pathologic features in PTC into clinical practice. It is im-
portant that potential markers be tested within relevant
clinical scenarios. Simply testing molecular markers for di-
agnosis or prognosis without placing them into clinical
context will not inform us of their true clinical utility.
Conclusion
This systematic review reveals that some miRs are associ-
ated with aggressive clinicopathologic features, such as large
tumor size, ETE, multifocality, LVI, LNM, distant metastasis,
advanced AJCC stage, and presence of the BRAF
V600E
muta-
tion. However, most of the studies examined were retrospec-
tive, and did not include patients who had undergone routine
CLND. Further studies are needed to investigate whether miRs
are independent predictors of aggressive clinicopathologic
features before it can be recommended that miR expression be
incorporated into the management algorithm for patients with
PTC. A well-designed prospective study is needed to assess
these potentially clinically useful associations.
Author Disclosure Statement
The authors have nothing to disclose related to this work.
References
1. Enewold L, Zhu K, Ron E, Marrogi AJ, Stojadinovic A,
Peoples GE, Devesa SS 2009 Rising thyroid cancer
incidence in the United States by demographic and tumor
characteristics, 1980–2005. Cancer Epidemiol Biomarkers
Prev 18:784–791.
6 ARAGON HAN ET AL.
2. Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL,
Mandel SJ, Mazzaferri EL, McIver B, Pacini F, Schlum-
berger M, Sherman SI, Steward DL, Tuttle RM 2009
Revised American Thyroid Association management
guidelines for patients with thyroid nodules and differen-
tiated thyroid cancer. Thyroid 19:1167–1214.
3. Xing M, Haugen BR, Schlumberger M 2013 Progress in
molecular-based management of differentiated thyroid
cancer. Lancet 381:1058–1069.
4. Mazzaferri EL, Doherty GM, Steward DL 2009 The pros
and cons of prophylactic central compartment lymph node
dissection for papillary thyroid carcinoma. Thyroid 19:
683–689.
5. Mazzaferri EL 2009 What is the optimal initial treatment of
low-risk papillary thyroid cancer (and why is it contro-
versial)? Oncology (Williston Park) 23:579–588.
6. Carling T, Long WD 3rd, Udelsman R 2010 Controversy
surrounding the role for routine central lymph node dis-
section for differentiated thyroid cancer. Curr Opin Oncol
22:30–34.
7. Jiang LH, Chen C, Tan Z, Lu XX, Hu SS, Wang QL, Hou
XX, Cao J, Ge MH 2014 Clinical characteristics related to
central lymph node metastasis in cN0 papillary thyroid
carcinoma: a retrospective study of 916 patients. Int J En-
docrinol 2014:385787.
8. Agrawal N, Akbani R, Aksoy BA, Ally A, Arachchi H, Asa
SL, Auman JT, Balasundaram M, Balu S, Baylin SB, Be-
hera M, Bernard B, Beroukhim R, Bishop JA, Black AD,
Bodenheimer T, Boice L, Bootwalla MS, Bowen J, Bowlby
R, Bristow CA, Brookens R, Brooks D, Bryant R, Buda E,
Butterfield YSN, Carling T, Carlsen R, Carter SL, Carty
SE, Chan TA, Chen AY, Cherniack AD, Cheung D, Chin L,
Cho J, Chu A, Chuah E, Cibulskis K, Ciriello G, Clarke A,
Clayman GL, Cope L, Copland JA, Covington K, Danilova
L, Davidsen T, Demchok JA, DiCara D, Dhalla N, Dhir R,
Dookran SS, Dresdner G, Eldridge J, Eley G, El-Naggar
AK, Eng S, Fagin JA, Fennell T, Ferris RL, Fisher S, Frazer
S, Frick J, Gabriel SB, Ganly I, Gao J, Garraway LA,
Gastier-Foster JM, Getz G, Gehlenborg N, Ghossein R,
Gibbs RA, Giordano TJ, Gomez-Hernandez K, Grimsby J,
Gross B, Guin R, Hadjipanayis A, Harper HA, Hayes DN,
Heiman DI, Herman JG, Hoadley KA, Hofree M, Holt RA,
Hoyle AP, Huang FW, Huang M, Hutter CM, Ideker T,
Iype L, Jacobsen A, Jefferys SR, Jones CD, Jones SJM,
Kasaian K, Kebebew E, Khuri FR, Kim J, Kramer R,
Kreisberg R, Kucherlapati R, Kwiatkowski DJ, Ladanyi M,
Lai PH, Laird PW, Lander E, Lawrence MS, Lee D, Lee E,
Lee S, Lee W, Leraas KM, Lichtenberg TM, Lichtenstein
L, Lin P, Ling S, Liu J, Liu W, Liu Y, LiVolsi VA, Lu Y,
Ma Y, Mahadeshwar HS, Marra MA, Mayo M, McFadden
DG, Meng S, Meyerson M, Mieczkowski PA, Miller M,
Mills G, Moore RA, Mose LE, Mungall AJ, Murray BA,
Nikiforov YE, Noble MS, Ojesina AI, Owonikoko TK,
Ozenberger BA, Pantazi A, Parfenov M, Park PJ, Parker JS,
Paull EO, Pedamallu CS, Perou CM, Prins JF, Protopopov
A, Ramalingam SS, Ramirez NC, Ramirez R, Raphael BJ,
Rathmell WK, Ren X, Reynolds SM, Rheinbay E, Ringel
MD, Rivera M, Roach J, Robertson AG, Rosenberg MW,
Rosenthal M, Sadeghi S, Saksena G, Sander C, Santoso N,
Schein JE, Schultz N, Schumacher SE, Seethala RR,
Seidman J, Senbabaoglu Y, Seth S, Sharpe S, Shaw KRM,
Shen JP, Shen R, Sherman S, Sheth M, Shi Y, Shmulevich
I, Sica GL, Simons JV, Sinha R, Sipahimalani P, Small-
ridge RC, Sofia HJ, Soloway MG, Song X, Sougnez C,
Stewart C, Stojanov P, Stuart JM, Sumer SO, Sun Y, Tabak
B, Tam A, Tan D, Tang J, Tarnuzzer R, Taylor BS,
Thiessen N, Thorne L, Thorsson V, Tuttle RM, Umbricht
CB, Van Den Berg DJ, Vandin F, Veluvolu U, Verhaak
RGW, Vinco M, Voet D, Walter V, Wang Z, Waring S,
Weinberger PM, Weinhold N, Weinstein JN, Weisenberger
DJ, Wheeler D, Wilkerson MD, Wilson J, Williams M,
Winer DA, Wise L, Wu J, Xi L, Xu AW, Yang L, Yang L,
Zack TI, Zeiger MA, Zeng D, Zenklusen JC, Zhao N,
Zhang H, Zhang J, Zhang J, Zhang W, Zmuda E, Zou L
2014 Integrated genomic characterization of papillary
thyroid carcinoma. Cell 159:676–690.
9. Zhou YL, Liu C, Dai XX, Zhang XH, Wang OC 2012
Overexpression of miR-221 is associated with aggressive
clinicopathologic characteristics and the BRAF mutation in
papillary thyroid carcinomas. Med Oncol 29:3360–3366.
10. Yip L, Kelly L, Shuai Y, Armstrong MJ, Nikiforov YE,
Carty SE, Nikiforova MN 2011 MicroRNA signature dis-
tinguishes the degree of aggressiveness of papillary thyroid
carcinoma. Ann Surg Oncol 18:2035–2041.
11. Wang Z, Zhang H, Zhang P, Li J, Shan Z, Teng W 2013
Upregulation of miR-2861 and miR-451 expression in
papillary thyroid carcinoma with lymph node metastasis.
Med Oncol 30:577.
12. Wang Z, Zhang H, He L, Dong W, Li J, Shan Z, Teng W
2013 Association between the expression of four upregu-
lated miRNAs and extrathyroidal invasion in papillary
thyroid carcinoma. Onco Targets Ther 6:281–287.
13. Sun Y, Yu S, Liu Y, Wang F, Liu Y, Xiao H 2013 Ex-
pression of miRNAs in papillary thyroid carcinomas is
associated with BRAF mutation and clinicopathological
features in Chinese patients. Int J Endocrinol 2013:128735.
14. Peng Y, Li C, Luo DC, Ding JW, Zhang W, Pan G 2014
Expression profile and clinical significance of microRNAs
in papillary thyroid carcinoma. Molecules 19:11586–11599.
15. Lee JC, Zhao JT, Clifton-Bligh RJ, Gill A, Gundara JS, Ip
JC, Glover A, Sywak MS, Delbridge LW, Robinson BG,
Sidhu SB 2013 MicroRNA-222 and microRNA-146b are
tissue and circulating biomarkers of recurrent papillary
thyroid cancer. Cancer 119:4358–4365.
16. Benvenga S, Koch CA 2014 Molecular pathways associ-
ated with aggressiveness of papillary thyroid cancer. Curr
Genomics 15:162–170.
17. Chou CK, Yang KD, Chou FF, Huang CC, Lan YW, Lee
YF, Kang HY, Liu RT 2013 Prognostic implications of
miR-146b expression and its functional role in papillary
thyroid carcinoma. J Clin Endocrinol Metab 98:E196–205.
18. Chou CK, Chen RF, Chou FF, Chang HW, Chen YJ,
Lee YF, Yang KD, Cheng JT, Huang CC, Liu RT 2010
miR-146b is highly expressed in adult papillary thyroid
carcinomas with high risk features including extrathyroidal
invasion and the BRAF(V600E) mutation. Thyroid 20:489–
494.
19. Aragon Han P, Olson MT, Fazeli R, Prescott JD, Pai SI,
Schneider EB, Tufano RP, Zeiger MA 2014 The impact of
molecular testing on the surgical management of patients
with thyroid nodules. Ann Surg Oncol 21:1862–1869.
20. Esquela-Kerscher A, Slack FJ 2006 Oncomirs—microRNAs
with a role in cancer. Nat Rev Cancer 6:259–269.
21. Acibucu F, Dokmetas HS, Tutar Y, Elagoz S, Kilicli F
2014 Correlations between the expression levels of micro-
RNA146b, 221, 222 and p27Kip1 protein mRNA and the
clinicopathologic parameters in papillary thyroid cancers.
Exp Clin Endocrinol Diabetes 122:137–143.
MIR AND THYROID CANCER PROGNOSIS 7
22. Dettmer M, Perren A, Moch H, Komminoth P, Nikiforov
YE, Nikiforova MN 2013 Comprehensive microRNA ex-
pression profiling identifies novel markers in follicular variant
of Papillary Thyroid Carcinoma. Thyroid 23:1383–1389.
23. Sheu SY, Grabellus F, Schwertheim S, Handke S, Worm K,
Schmid KW 2009 Lack of correlation between BRAF
V600E mutational status and the expression profile of a
distinct set of miRNAs in papillary thyroid carcinoma.
Hormone Metab Res 41:482–487.
24. Wang P, Meng W, Jin M, Xu L, Li E, Chen G 2012 In-
creased expression of miR-221 and miR-222 in patients
with thyroid carcinoma. Afr J Biotechnol 11:2774–2781.
25. Yu S, Liu Y, Wang J, Guo Z, Zhang Q, Yu F, Zhang Y,
Huang K, Li Y, Song E, Zheng XL, Xiao H 2012 Circu-
lating microRNA profiles as potential biomarkers for di-
agnosis of papillary thyroid carcinoma. J Clin Endocrinol
Metab 97:2084–2092.
26. Higgins JP, Green S 2008 Cochrane Handbook for Systematic
Reviews of Interventions. Vol. 5. Wiley Online Library.
27. Moher D, Liberati A, Tetzlaff J, Altman DG, Group P 2009
Preferred reporting items for systematic reviews and meta-
analyses: the PRISMA statement. J Clin Epidemiol
62:1006–1012.
28. Huang YB, Liao DH, Pan LX, Ye RY, Li XX, Wang SM,
Ye CS, Chen LH 2013 Expressions of miRNAs in papillary
thyroid carcinoma and their associations with the
BRAF(V600E) mutation. Eur J Endocrinol 168:675–681.
29. Wells G, Shea B, O’Connell D, Peterson J, Welch V, Losos
M, Tugwell P 2000 The Newcastle–Ottawa Scale (NOS)
for assessing the quality of nonrandomised studies in meta-
analyses. Department of Epidemiology and Community
Medicine, University of Ottowa, Canada.
30. Margulis AV, Pladevall M, Riera-Guardia N, Varas-
Lorenzo C, Hazell L, Berkman ND, Viswanathan M, Perez-
Gutthann S 2014 Quality assessment of observational
studies in a drug-safety systematic review, comparison of
two tools: the Newcastle–Ottawa Scale and the RTI item
bank. Clin Epidemiol 6:359–368.
31. Vincent K, Pichler M, Lee GW, Ling H 2014 MicroRNAs,
genomic instability and cancer. Int J Mol Sci 15:14475–14491.
32. Pallante P, Battista S, Pierantoni GM, Fusco A 2014 De-
regulation of microRNA expression in thyroid neoplasias.
Nat Rev Endocrinol 10:88–101.
33. Li C, Aragon Han P, Lee KC, Lee LC, Fox AC, Beninato T,
Thiess M, Dy BM, Sebo TJ, Thompson GB, Grant CS,
Giordano TJ, Gauger PG, Doherty GM, Fahey TJ 3rd,
Bishop J, Eshleman JR, Umbricht CB, Schneider EB,
Zeiger MA 2013 Does BRAF V600E mutation predict ag-
gressive features in papillary thyroid cancer? Results from
four endocrine surgery centers. J Clin Endocrinol Metab
98:3702–3712.
34. Haider BA, Baras AS, McCall MN, Hertel JA, Cornish TC,
Halushka MK 2014 A critical evaluation of microRNA
biomarkers in non-neoplastic disease. PLoS One 9:e89565.
35. Witwer KW 2015 Circulating microRNA biomarker stud-
ies: pitfalls and potential solutions. Clin Chem 61:56–63.
Address correspondence to:
Martha A. Zeiger, MD
Professor of Surgery, Oncology, Cellular
and Molecular Medicine
Chief of Endocrine Surgery
Johns Hopkins Hospital
600 N. Wolfe Street
Department of Surgery
Block 606
Baltimore, MD 21287
E-mail: mzeiger@jhmi.edu
8 ARAGON HAN ET AL.
