Roula Albadine's research while affiliated with Université de Montréal and other places

Patients with non-small cell lung cancer (NSCLC) harboring ROS proto-oncogene 1 (ROS1) gene rearrangements show dramatic response to the tyrosine kinase inhibitor (TKI) crizotinib. Current best practice guidelines recommend that all advanced stage non-squamous NSCLC patients be also tested for ROS1 gene rearrangements. Several studies have suggested that ROS1 immunohistochemistry (IHC) using the D4D6 antibody may be used to screen for ROS1 fusion positive lung cancers, with assays showing high sensitivity but moderate to high specificity. A break apart fluorescence in situ hybridization (FISH) test is then used to confirm the presence of ROS1 gene rearrangement. The goal of Canadian ROS1 (CROS) study was to harmonize ROS1 laboratory developed testing (LDT) by using IHC and FISH assays to detect ROS1 rearranged lung cancers across Canadian pathology laboratories. Cell lines expressing different levels of ROS1 (high, low, none) were used to calibrate IHC protocols after which participating laboratories ran the calibrated protocols on a reference set of 24 NSCLC cases (9 ROS1 rearranged tumors and 15 ROS1 non-rearranged tumors as determined by FISH). Results were compared using a centralized readout. The stained slides were evaluated for the cellular localization of staining, intensity of staining, the presence of staining in non-tumor cells, the presence of non-specific staining (e.g. necrosis, extracellular mater, other) and the percent positive cells. H-score was also determined for each tumor. Analytical sensitivity and specificity harmonization was achieved by using low limit of detection (LOD) as either any positivity U118 cell line or H-score of 200 with the HCC78 cell line. An overall diagnostic sensitivity and specificity of up to 100% and 99% respectively was achieved for ROS1 IHC testing (relative to FISH) using an adjusted H-score readout on the reference cases. This study confirms that LDT ROS1 IHC assays can be highly sensitive for detection of ROS1 rearrangements in NSCLC. As NSCLC can demonstrate ROS1 IHC positivity in FISH-negative cases, the degree of the specificity of the IHC assay, especially in highly sensitive protocols, is mostly dependent on the readout cut-off threshold. As ROS1 IHC is a screening assay for a rare rearrangement in NSCLC, we recommend adjustment of the readout threshold in order to balance specificity, rather than decreasing the overall analytical and diagnostic sensitivity of the protocols.

Background: Studies have shown that aggressive treatment of non-small cell lung cancer (NSCLC) with oligometastatic disease improves the overall survival (OS) compared to a palliative approach and some immunotherapy checkpoint inhibitors, such as anti-programmed cell death ligand 1 (PD-L1), anti-programmed cell death protein 1 (PD-1), and T-Lymphocyte-associated antigen 4 (CTLA-4) inhibitors are now part of the standard of care for advanced NSCLC. However, the prognostic impact of PD-L1 expression in the oligometastatic setting remains unknown. Methods: Patients with oligometastatic NSCLC were identified from the patient database of the Centre hospitalier de l'Université de Montréal (CHUM). "Oligometastatic disease" definition chosen is one synchronous metastasis based on the M1b staging of the eight IASLC (The International Association for the Study of Lung Cancer) Classification (within sixth months of diagnosis) or up to three cerebral metastasis based on the methodology of the previous major phase II randomized study of Gomez et al. We compared the OS between patients receiving aggressive treatment at both metastatic and primary sites (Group A) and patients receiving non-aggressive treatment (Group B). Subgroup analysis was performed using tumor PD-L1 expression. Results: Among 643 metastatic NSCLC patients, we identified 67 patients with oligometastasis (10%). Median follow-up was 13.3 months. Twenty-nine patients (43%) received radical treatment at metastatic and primary sites (Group A), and 38 patients (57%) received non-aggressive treatment (Group B). The median OS (mOS) of Group A was significantly longer than for Group B (26 months vs. 5 months, p = 0.0001). Median progression-free survival (mPFS) of Group A was superior than Group B (17.5 months vs. 3.4 months, p = 0.0001). This difference was still significant when controlled for primary tumor staging: stage I (p = 0.316), stage II (p = 0.024), and stage III (p = 0.001). In the cohort of patients who were not treated with PD-L1 inhibitors, PD-L1 expression negatively correlated with mOS. Conclusions: Aggressive treatments of oligometastatic NSCLC significantly improve mOS and mPFS compared to a more palliative approach. PD-L1 expression is a negative prognostic factor which suggests a possible role for immunotherapy in this setting.

Background PD-L1 immunohistochemistry (IHC) assay is used to select patients for first/second line pembrolizumab monotherapy in non-small cell lung carcinoma (NSCLC). The PD-L1 IHC 22C3 pharmDx assay requires Autostainer Link 48 instrument. Laboratories without this stainer may optionally develop highly accurate 22C3 IHC laboratory-developed test (LDT) on other instruments. The Canadian 22C3 IHC LDT validation project was initiated to harmonize the quality of PD-L1 22C3 IHC LDT protocols across 20 Canadian pathology laboratories. Methods Centrally optimized 22C3 LDT protocols were distributed to participating laboratories. The LDT results were assessed against result using reference PD-L1 IHC 22C3 pharmDx. Analytical sensitivity and specificity were assessed using cell lines with varying PD-L1 expression levels (Phase 1) and IHC Critical Assay Performance Controls (iCAPCs) (Phase 2B). Diagnostic sensitivity and specificity were assessed using whole sections of 50 NSCLC cases (Phase 2A), and tissue microarrays with additional 50 NSCLC cases (Phase 2C). Results In Phase 1, 80% participants reached acceptance criteria for analytical performance in the first attempt with disseminated protocols. However, in Phase 2A only 40% of participants reached desired diagnostic accuracy for both 1% and 50% TPS cut-off. In Phase 2B, further protocol modifications were conducted, which increased the number of successful laboratories to 75% in Phase 2C. Conclusions It is possible to harmonize highly accurate 22C3 LDTs for both 1% and 50% TPS in NSCLC across many laboratories with different platforms. However, despite centralized approach, diagnostic validation of predictive IHC LDTs can be challenging and not always successful.

The ros1 kinase is an oncogenic driver in non-small-cell lung cancer (nsclc). Fusion events involving the ROS1 gene are found in 1%-2% of nsclc patients and lead to deregulation of a tyrosine kinase-mediated multi-use intracellular signalling pathway, which then promotes the growth, proliferation, and progression of tumour cells. ROS1 fusion is a distinct molecular subtype of nsclc, found independently of other recognized driver mutations, and it is predominantly identified in younger patients (<50 years of age), women, never-smokers, and patients with adenocarcinoma histology. Targeted inhibition of the aberrant ros1 kinase with crizotinib is associated with increased progression-free survival (pfs) and improved quality-of-life measures. As the sole approved treatment for ROS1-rearranged nsclc, crizotinib has been demonstrated, through a variety of clinical trials and retrospective analyses, to be a safe, effective, well-tolerated, and appropriate treatment for patients having the ROS1 rearrangement. Canadian physicians endorse current guidelines which recommend that all patients with nonsquamous advanced nsclc, regardless of clinical characteristics, be tested for ROS1 rearrangement. Future integration of multigene testing panels into the standard of care could allow for efficient and cost-effective comprehensive testing of all patients with advanced nsclc. If a ROS1 rearrangement is found, treatment with crizotinib, preferably in the first-line setting, constitutes the standard of care, with other treatment options being investigated, as appropriate, should resistance to crizotinib develop.

Background Inhibition of the anaplastic lymphoma kinase (alk) oncogenic driver in advanced non-small-cell lung carcinoma (nsclc) improves survival. In 2015, Canadian thoracic oncology specialists published a consensus guideline about the identification and treatment of ALK-positive patients, recommending use of the alk inhibitor crizotinib in the first line. New scientific literature warrants a consensus update.Methods Clinical trials of alk inhibitor were reviewed to assess benefits, risks, and implications relative to current Canadian guidance in patients with ALK-positive nsclc.ResultsRandomized phase iii trials have demonstrated clinical benefit for single-agent alectinib and ceritinib used in treatment-naïve patients and as second-line therapy after crizotinib. Phase ii trials have demonstrated activity for single-agent brigatinib and lorlatinib in further lines of therapy. Improved responses in brain metastases were observed for all second- and next/third-generation alk tyrosine kinase inhibitors in patients progressing on crizotinib. Canadian recommendations are therefore revised as follows:Patients with advanced nonsquamous nsclc have to be tested for the presence of an ALKrearrangement.Treatment-naïve patients with ALK-positive disease should initially be offered single-agent alectinib or ceritinib, or both sequentially.Crizotinib-refractory patients should be treated with single-agent alectinib or ceritinib, or both sequentially.Further treatments could include single-agent brigatinib or lorlatinib, or both sequentially.Patients progressing on alk tyrosine kinase inhibitors should be considered for pemetrexed-based chemotherapy.Other systemic therapies should be exhausted before immunotherapy is considered.SummaryMultiple lines of alk inhibition are now recommended for patients with advanced nsclc with an ALKrearrangement.

Anaplastic lymphoma kinase (ALK) is an oncogenic driver in non-small-cell lung cancer (NSCLC). Chromosomal rearrangements involving the ALK gene occur in up to 4% of nonsquamous NSCLC patients and lead to constitutive activation of the ALK signalling pathway. ALK-positive NSCLC is found in relatively young patients, with a median age of 50 years. Patients frequently have brain metastasis.Targeted inhibition of the ALK pathway prolongs progression-free survival in patients with ALK-positive advanced NSCLC. The results of several recent clinical trials confirm the efficacy and safety benefit of crizotinib and ceritinib in this population.Canadian oncologists support the following consensus statement: All patients with advanced nonsquamous nsclc (excluding pure neuroendocrine carcinoma) should be tested for the presence of an ALK rearrangement. If an ALK rearrangement is present, treatment with a targeted ALK inhibitor in the first-line setting is recommended. As patients become resistant to first-generation ALK inhibitors, other treatments, including second-generation ALK inhibitors can be considered.

Introduction: Fluorescence in situ hybridization (FISH) is currently the standard for diagnosing anaplastic lymphoma kinase (ALK)-rearranged (ALK+) lung cancers for ALK inhibitor therapies. ALK immunohistochemistry (IHC) may serve as a screening and alternative diagnostic method. The Canadian ALK (CALK) study was initiated to implement a multicenter optimization and standardization of laboratory developed ALK IHC and FISH tests across 14 hospitals. Methods: Twenty-eight lung adenocarcinomas with known ALK status were used as blinded study samples. Thirteen laboratories performed IHC using locally developed staining protocols for 5A4, ALK1, or D5F3 antibodies; results were assessed by H-score. Twelve centers conducted FISH using protocols based on Vysis' ALK break-apart FISH kit. Initial IHC results were used to optimize local IHC protocols, followed by a repeat IHC study to assess the results of standardization. Three laboratories conducted a prospective parallel IHC and FISH analysis on 411 consecutive clinical samples using post-validation optimized assays. Results: Among study samples, FISH demonstrated 22 consensus ALK+ and six ALK wild type tumors. Preoptimization IHC scores from 12 centers with 5A4 and the percent abnormal cells by FISH from 12 centers showed intraclass correlation coefficients of 0.83 and 0.68, respectively. IHC optimization improved the intraclass correlation coefficients to 0.94. Factors affecting FISH scoring and outliers were identified. Post-optimization concurrent IHC/FISH testing in 373 informative cases revealed 100% sensitivity and specificity for IHC versus FISH. Conclusions: Multicenter standardization study may accelerate the implementation of ALK testing protocols across a country/region. Our data support the use of an appropriately validated IHC assay to screen for ALK+ lung cancers.

e22159 Background: Recent advances in lung cancer treatment embrace the recognition of molecular pathways implicated in its pathogenicity, paving the path to personalized therapies. We conducted a retrospective analysis to characterize the molecular features of the population treated for non-squamous non-small cell lung cancer (NS-NSCLC) in the province of Quebec. Methods: 622 patients with NS-NSCLC and adequate tumor blocks, treated at the CHUM between 2006 and 2008, were included. All samples were tested for ALK translocations (by IHC and FISH), EGFR classical exon 19 and 21 mutations by PCR (fragment analysis and qPCR) and for KRAS codon 12 and 13 mutations by mismatch PCR-RFLP. Molecular features were matched to demographic characteristics and clinical outcomes. Results: So far, complete results are available for 153 patients. Considering the amount of tumor tissue available, this population is largely represented by patients with local or loco-regional disease (n= 140, 91.5%). A minority of patients (10.3%) was never or light smokers (< 10 pack-yrs). Only 2 patients (1.3%) were of Asian descent. The following table depicts the outcomes of this cohort of patients segregated according to mutation status and extent of disease. Conclusions: ALK rearrangements were not identified in this unselected NS-NSCLC population characterized by localized disease and strong smoking history. ALK translocation prevalence in different populations is likely to be largely influenced by its tumor stage distribution, tobacco exposure and the use of selection criteria for molecular testing. An expanded cohort of patients will be presented at the meeting. [Table: see text]

8096 Background: ALK gene rearrangement (ALK+) has been found in 3-5% of advanced non-small cell lung cancer patients. FISH is considered the “gold standard” for identification of ALK+ tumors, but its cost-effectiveness and adoption as a screening assay has been debated. Recent reports suggested that ALK IHC may serve as an alternative screening or possibly a diagnostic method. In this context, CALK was initiated to assess the feasibility of implementing ALK IHC and/or FISH assays across Canadian hospitals. Methods: FISH-confirmed 22 ALK+ and 6 ALK- tumors were used as study samples. Unstained sections and scanned images of HE-stained slides from each tumor block were distributed to participating centres. IHC protocols with best signal to noise ratio using the 5A4 (Novocastra) or ALK-1 (Dako) antibodies were developed for various auto-stainers and implemented to suit the existing conditions of the participating centres. A common FISH protocol using the ALK break-apart probe (Abbott Molecular, Chicago, IL) was developed based on published reports. H-score was used to assess IHC. FISH signals were scored in 100 tumor cells/case by 2-3 pre-trained persons. A second round IHC study using newly distributed slides was completed by 8 centres. Results: Independent IHC scores from 12 centres and FISH scores from 11 centres were collected and analysed. The intraclass correlation coefficients (ICC) between centres for IHC and FISH were 0.84 and 0.68, respectively. Following the analysis of initial IHC results, a second round study resulted in improved ICC of 0.94. One of 23 tumors revealed IHC-/FISH+ discrepancy, with the FISH revealing unusual signal configurations that suggested an atypical rearrangement. However, the sensitivity and specificity of FISH results across centres using the 15 aberrant signals cut-off ranged from 86.7-100% and 100%, respectively. Conclusions: Standardization across multiple centres for ALK testing by IHC and FISH can be achieved. IHC detected all FISH+ ALK tumors, except for one discrepant case with atypical FISH finding of unknown clinical implication. The study was supported by a Pfizer Canada grant.