Journal Thoracic Oncology

Abstracts Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017
bone (20/58%), brain (18/52%) and liver (13/38%). All patients received
erlotinib as first- line treatment and documented mutations were: 60% DelE19
(Del746–750) and 40% L858R. Overall response rate (ORR) with first line
TKI was 61.8% and progression free survival (PFS) was 16.8 months (range,
13.7–19.9 m). After progressing to TKI, all patients were re-biopsied, of whom
16 had the T790M mutation (47.1%); 5 had PI3K mutations (14.7), 5 had EGFR
amplification (14.7%), 2 had a KRAS mutation (5.9%), 3 had MET amplification
(8.8%), 2 had Her2 alterations (5.8%, deletions/insertions in e20), and one
had SCLC transformation (2.9%). 79.4% received treatment after progression.
ORR for post-TKI treatments was 47.1% (CR 2/PR 14) and median PFS was
8.3 months (CI95% 2.2–36.6). There were no differences in PFS according to
gender (p=0.10) or type of acquired alteration (p=0.63). Median survival was
32.9 months (CI95% 30.4–35.3), and only the use of post-progression therapy
affected OS in multivariate analysis (p=0.05). Conclusion: Hispanic patients
with acquired resistance to EGFR TKIs continued to be sensitive to other
treatments after progression. Proportion of T790M+ patients appears to be
similar to previously reported results in Caucasians.
Keywords: Acquired resistance, EGFR-mutant lung adenocarcinoma, EGFR
Tyrosine Kinase Inhibitors, Hispanics
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-051 CONCOMITANT DRIVER MUTATIONS IN ADVANCED
STAGE NON-SMALL-CELL LUNG CANCER OF ADENOCARCINOMA
SUBTYPE WITH ACTIVATING EGFR-MUTATION
Jens Benn Sørensen 1 , Morten Grauslund 2 , Linea Melchior 2 , Jan Jakobsen 1 , Eric
Santoni-Rugiu 2
1 Dept. Oncology, Finsen Centre/national University Hospital, Copenhagen/
Denmark, 2 Dept. Pathology, National University Hospital, Copenhagen/Denmark
Background: Patients having non-small-cell lung cancer (NSCLC) with
activating EGFR-mutations benefit from EGFR-Tyrosine Kinase Inhibitor
(TKI) treatment. However, other driver mutations may occur simultaneously
and other pathways may be amplified/overexpressed, potentially hampering
efficacy of EGFR-TKI treatment. The frequency of such alterations at time of
diagnosis was examined. Methods: All patients referred to Rigshospitalet,
Copenhagen University Hospital for pulmonary adenocarcinoma (ADC)
from July 2013 to August 2015 were routinely tested for EGFR-mutations
by EGFR Cobas RT-PCR technique (Roche Diagnostics) on DNA extracted
from diagnostic tumor biopsies or cytological samples. If positive for
EGFR-mutations these patients were, prior to any treatment, also tested by
targeted Next Generation Sequencing (NGS; Ion Torrent Ampliseq Colon-Lung
v.2 panel and PGM NGS-sequenator) for other simultaneous cancer-relevant
mutations, by fluorescence in-situ hybridization (FISH) for MET-amplification,
and by immunohistochemistry (IHC) for expression of MET receptor as well
as ALK fusion-protein. Results: Totally 512 ADC patients were tested, among
whom 22 out of 282 advanced stage patients (7.8%) had activating EGFRmutations,
distributed as follows: 1 G719C-mutation, 13 exon 19-deletions,
1 T790M-mutation, 1 S768I-mutation and 8 L858R-mutations with 2 of the
patients harboring EGFR-double-mutations G719C + S768I and L858R + T790M
(i.e., activating and resistance mutation), respectively. Complete concordance
between EGFR-mutation-status by EGFR Cobas and NGS was observed for
all NGS tested patients. For one of the patients NGS analysis could not be
carried out, due to lacking DNA-extract and remaining tumor tissue. NGSanalysis
identified several concomitant driver mutations in the 21 analyzed
patients, including one 1 with KRAS-mutation (G12V), 12 with TP53-mutations
(7 in TP53-exon 5), 1 with FGFR-mutation (S125_E126insS), 2 with CTNNB1-
mutations (S33C and S37F), 1 with MET-mutation (T1010I), 1 with SMAD4-
mutation (R135stop), and 1 with PIK3CA-mutation (E545K). FISH and IHC for
MET were successful in tumor samples from 16 and 19 patients, respectively.
Three patients had concomitant MET-amplification (1 with and 1 without
corresponding MET-overexpression, 1 with unsuccessful IHC), whereas 2 other
patients had increased copy number (ICN; both with corresponding METoverexpression).
Interestingly, 4 of these 5 patients with MET-amplification
or -ICN also carried TP53-mutations. Expression of ALK fusion-protein was
not detected in any of the 22 patients with activating EGFR mutations.
Conclusion: At time of diagnosis, concomitant mutations in other cancer
driver genes can be detected in advanced EGFR-mutation-positive NSCLC of
ADC subtype. These concomitant mutations may impact the response to firstline
EGFR-TKI treatment and represent additional therapeutic targets.
Keywords: EGFR mutation, next generation sequencing, MET amplification,
MET expression
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-052 SIGNAL REGULATORY PROTEIN A (SIRPA): A KEY
REGULATOR OF THE EGFR PATHWAY DEMONSTRATES BOTH
TUMOR SUPPRESSIVE AND ONCOGENIC PROPERTIES
Erin Marshall 1 , Larissa Pikor 1 , Raj Chari 2 , Jennifer Kennett 1 , Stephen Lam 1 ,
Wan Lam 1
1 Integrative Oncology, BC Cancer Research Centre, Vancouver/BC/Canada, 2 Harvard
Medical School, Boston/MA/United States of America
Background: The epidermal growth factor receptor (EGFR) signaling pathway
is one of the most frequently deregulated pathways in non-small cell lung
cancer. While targeted therapy prolongs survival in patients harbouring
EGFR mutations, resistance to treatment eventually develops in all cases. As
multiple genetic and epigenetic alterations are known to disrupt signaling
pathways, the objective of this study is to perform a multidimensional
analysis of signaling pathways to identify alterations essential to
tumorigenesis that are overlooked when assessing a single genomic
dimension. Methods: Multidimensional integrative analysis of copy number,
DNA methylation, and gene expression profiles of 77 lung adenocarcinomas
and matched non-malignant tissues identified Signal Regulatory Protein A
(SIRPA) as a novel candidate tumor suppressor gene. Following validation
of genomic findings in multiple external data sets, the tumor suppressive
effects of SIRPA were assessed in vitro and in vivo with a panel of lung cancer
cell lines. Results: SIRPA negatively regulates receptor tyrosine kinase
signaling through activation of the protein phosphatases SHP1 and SHP2 and
was found to be underexpressed in 70% of lung tumours, ranking it in the 95 th
percentile of altered genes within the EGFR pathway. Immunohistochemistry
(IHC) confirmed reduced protein expression in tumors, which was found to
correlate with EGFR mutation and adenocarcinoma histology. In vitro, SIRPA
knockdown promoted migration while simultaneously inducing a dramatic
senescent phenotype, suggesting SIRPA may act as a barrier to tumorigenesis.
This phenotype is dependent upon upregulation of the CDK inhibitor p27,
which hypophosphorylates RB leading to cell cycle blockade and reduced
tumor growth in vivo. Importantly, increased expression of p27 resulted in
mis-localization into the cytoplasm where it is known to promote an invasive
phenotype. Inhibition of p27 confirmed previous findings and emphasized
the importance of this pathway in lung tumorigenesis. Surprisingly,
overexpression of SIRPA increased cell growth and migration, suggesting
SIRPA may also possess oncogenic properties due to its regulation of multiple
signaling pathways. Overexpression of SHP2 following ectopic expression
of SIRPA promotes migration through the inhibition of focal adhesions.
This phenotype is abrogated upon siRNA knockdown of SHP2. Conclusion:
SIRPA is an important player in lung tumor biology, capable of acting as both
an oncogene and tumor suppressor due to its ability to regulate multiple
signaling pathways. Due to the complex nature in its signaling, future work
should focus on elucidating how the timing of alterations to SIRPA affects
tumorigenesis to design treatment strategy.
Keywords: non-small cell lung cancer, SIRPA, oncogene, tumour supressor
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-053 COMPARISON OF TWO DIFFERENT COMMERCIALLY
AVAILABLE PROBES FOR THE DETECTION OF ALK
REARRANGEMENTS IN CYTOLOGICAL SMEARS
Maria Lozano Escario 1 , Mercedes Aguirre 1 , Maria Eugenia Echarri 1 , Jose
Echeveste 1 , Nerea Gomez 1 , Maria Amada Maset 1 , Marta Abengozar 1 , Luis
Mejias 1 , Alfonso Gurpide 2 , Salvador Martin-Algarra 2
1 Pathology, University of Navarra, Pamplona/Spain, 2 Medical Oncology, University
of Navarra, Pamplona/Spain
Background: Many patients with NSCLC are diagnosed at advanced stages.
A high percentage of those patients have only cytological samples for
morphological and molecular analysis. Furthermore ALK analysis by FISH has
to be performed using a specific commercially available probe. The aim of this
study is to compare two different commercially available probes for analysis
of ALK gene rearrangements by FISH using cytological stained smears.
Methods: We analyzed 37 cytological stained smears from 37 consecutive
cases of FNA (14 Diff-Quick and 23 Papanicolau). ROSE was performed in all
procedures. The status of EGFR, KRAS and BRAF was kwon in 28 patients.
Two probes were used: LSI ALK BREAK APART (Vysis, Ref: 53206N38020,
Izasa) was apply in all 37 cases. Additionally, in 25 of these cases we used
the ZytoLight SPEC ALK Dual Color Break Apart (ZYTOVISION, Ref: Z-2124-
200, Menarini Diagnostics) probe. Protocols were modified from Basel
and Zytolight manufacture guidelines. In order to optimize the amount of
probe and to evaluate individual nuclei, we delimited an area on each smear
Copyright © 2016 by the International Association for the Study of Lung Cancer
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