Journal Thoracic Oncology

Abstracts Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017
to an acid decalcified specimen and was not evaluated by FISH. Focal intense
stain was observed in 5 samples, 3 corresponded to surgical specimens and the
rest to small needle biopsies, one of the surgical specimens was FISH positive
and the rest, negative. Conclusion: Since FDA approval of Ventana ALK (D5F3)
IHC CDx Assay, IHC has become a widely used tool for assessing ALK status.
Guidelines suggest that weak granular stain should be interpreted as negative
and focal intense granular stain in any number of cells, as positive. Even though
our sample is small, moderate granular stain was consistently negative by FISH
analysis, however, focal intense stain shows more discordant results between
tests. To date, no suggestions are made on what should be the minimum
amount of tumor in a sample to report an IHC assay. Even though some of
these patients with IHC positive/FISH negative results have been reported
as responders to Crizotinib, further studies are needed. One specimen with
moderate cytoplasmic IHC stain was uninformative due to lack of signals. This
raises the issue of the need to standardize preanalytical variables, which can be
difficult in some areas of Latin America.
Keywords: ALK, Non Small Cell Lung Carcinoma, Immunohistochemistry
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-030 PERFORMANCE EVALUATION OF ALK/ROS1 DUAL BREAK
APART FISH PROBE KIT (RUO) IN NON-SMALL-CELL LUNG CANCER
Hyun Chang 1 , Sun Min Lim 2 , Hye Ryun Kim 2 , Yoon Jin Cha 3 , Liang Shel 4 , Gu Li 4 ,
Yan Chin Tai 5 , Ekaterina Pestova 4 , Frank Polichit 4 , Thomas Perez 4 , Ross Soo 6 ,
Won Young Park 7 , Hyo Sup Shim 7 , Byoung Chul Cho 2
1 Hematology and Medical Oncology, Catholic Kwandong University International
St. Mary’s Hospital, Incheon/Korea, Republic of, 2 Division of Medical Oncology,
Yonsei Cancer Center, Yonsei University College of Medicine, Seoul/Korea, Republic
of, 3 Department of Pathology, Gangnam Severance Hospital, Seoul/Korea, Republic
of, 4 Abbott Molecular Inc, Des Plaines/IL/United States of America, 5 Abbott
Laboratories (Singapore), Singapore/Singapore, 6 Haematology-Oncology, National
University Health System, Singapore/Singapore, 7 Department of Pathology,
Severance Hospital, Yonsei University College of Medicine, Seoul/Korea, Republic of
Conclusion: These findings verify the feasibility of analysis of oncogenic drivers
in cytological specimens in advanced ADC. Stained aspiration smears can be
used after establishing diagnosis and checking adequacy of the specimen.
Keywords: oncogenic Drivers, pulmonary adenocarcinoma, pleural effusions,
FNA smear
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-029 INFREQUENT STAINING PATTERNS IN ALK
IMMUNOHISTOCHEMISTRY: CORRELATION WITH FISH ANALYSIS
Paola De La Iglesia 1 , Mercedes Dalurzo 2
1 Pathology, Hospital Italiano de Buenos Aires, Buenos Aires/Argentina, 2 Pathology,
Hospital Italiano de Buenos Aires, Ciudad Autonoma de Buenos Aires/Argentina
Background: AKL gene rearrangements are predictive alterations in non small
cell lung carcinomas (NSCLC). Immunohistochemistry (IHC) has become a
valuable tool in assessing ALK status, however unusual staining patterns, such
as heterogeneous diffuse moderate and focal intense stains, may occur and
can make evaluation difficult. Methods: We correlated immunohistochemistry
unusual staining patterns with ALK status by fluorescence in situ hybridization
(FISH). Of 851 cases tested, we found 14 (1.6%) cases with inconclusive staining
patterns that can be summarized in: a) diffuse granular cytoplasmic moderate
stain, with or without background mucin stain (10 cases) b) focal intense
granular cytoplasmic stain in overall negative or weakly positive tumors (4
cases). IHC was performed on an automatized Benchmark staining module
using Ventana ALK (D5F3) CDx assay with Optiview amplification kit. FISH was
performed using ALK break-apart probe set (Vysis LSI ALK Dual Color, Abbott
Molecular). Cases were considered ALK-FISH positive if ≥15% tumor cells showed
split red and green signals (separation of 2 diameters or more) and/or single red
signals Results: Of 10 moderate granular cytoplasmic stain cases, 4 had also
abundant mucin backround stain 6 where markedly heterogeneous with areas
of weak and moderate cytoplasmic granular stain. Nine were FISH negative,
one yielded no signals (uninformative result) and one specimen corresponded
Background: ALK and ROS1 gene rearrangements are distinct molecular
subsets of non-small-cell lung cancer (NSCLC), and they are strong predictive
biomarkers of response to ALK/ROS1 inhibitors, such as crizotinib. Thus,
it is clinically important to detect patients who will benefit from such
treatment and develop an effective screening strategy. In this study, we
aim to evaluate the diagnostic performance of ALK/ROS1 RUO FISH probes
which can concurrently detect ALK and ROS1 rearrangements. Methods:
The study populations were composed of three patient cohorts with
histologically confirmed lung adenocarcinoma (ALK rearrangement, ROS1
rearrangement and both wild type). Patient specimens consisted of 12
ALK-positive, 9 ROS1-positive and 21 ALK/ROS1-wild type formalin-fixed
paraffin-embedded samples obtained from surgical resection or excisional
biopsy. ALK rearrangement status was determined by Vysis LSI Dual Color
Break Apart Rearrangement Probe (Abbott Molecular, Abbott Park, IL, USA)
and ROS1 rearrangement status was assessed by ZytoLight SPEC ROS1 dual
color break apart probe (Zytovision. Bremerhaven, Germany). All specimens
were re-evaluated by ALK/ROS1 Break Apart FISH RUO 4-color kit. FISH
images were scanned via the BioView Duet and interpreted remotely via
BioView SoloWeb. Results: A total of 42 patient samples were evaluated.
The concordance of results obtained from ALK/ROS1 Break Apart FISH RUO
4-color kit was evaluated relative to the ALK and ROS1 rearrangement status
of the specimen, as previously determined. One ROS1-positive and 2 wild-type
samples were excluded from analysis due to high background. Regarding 12
ALK-positive samples, 12 were ALK-positive by ALK/ROS1 RUO FISH, showing
100% (n=12/12) sensitivity to predict ALK rearrangement. Regarding 8 ROS1-
positive samples, 6 cases were ROS1-positive by ALK/ROS1 RUO FISH, showing
75% (n=6/8) sensitivity to predict ROS1 rearrangement. Two cases showed
weak ROS1 signals that could not be enumerated. Regarding 19 wild type
cases, 18 cases were negative by ALK/ROS1 RUO FISH, showing 95% (n=18/19)
specificity, while one case showed poor ROS1 signals which could not be
properly enumerated. Conclusion: ALK/ROS1 RUO FISH can detect ALK and
ROS1 rearrangements simultaneously in NSCLC. The fluorescence of ROS1
signal may be weakened by slide shipment and remote scoring.
Keywords: ALK, ROS1, fluorescent in situ hybridization, non-small-cell lung cancer
POSTER SESSION 1 - P1.02: BIOLOGY/PATHOLOGY
DRIVER GENES IN NSCLC, RESISTANCE, AND OTHER –
MONDAY, DECEMBER 5, 2016
P1.02-031 MUTATIONS IN TP53, PIK3CA, PTEN AND OTHER GENES
IN EGFR MUTATED LUNG CANCERS: CORRELATION WITH CLINICAL
OUTCOMES
S260 Journal of Thoracic Oncology • Volume 12 Issue S1 January 2017