PhD Scientific Days 2020

Pathology and Oncology II. Lectures

Reduced Isolated Red Signal Pattern of ALK FISH in Lung Cancer Patients

Előadó neve

Dr. Kocsmár, Ildikó

Előadó munkahelye

2nd Department of Pathology, Faculty of Medicine, Semmelweis University

Előadó telefonszáma

+36305243790

Előadó e-mail címe

ildi.kocsmar@gmail.com

Az előadás címe

Reduced Isolated Red Signal Pattern of ALK FISH in Lung Cancer Patients

Szerző(k) neve és munkahelye

Ildikó Kocsmár1, Gábor Smuk2, Gábor Pajor2, Éva Kocsmár1, Károly Szuhai3, Tamás Tornóczky2 and Gábor Lotz1
1 2nd Department of Pathology, Faculty of Medicine, Semmelweis University, Budapest
2 Department of Pathology, Medical School, University of Pécs, Pécs
3 Department of Molecular Cell Biology, Leiden University Medical Center, Leiden

Szekció

Pathology and Oncology II. Lectures

Language of the presentation

Hungarian

Section, first choice

Pathology and Oncology

Section, second choice

Molecular Sciences

Összefoglaló szövege

Introduction
Fluorescence in situ hybridization (FISH) is widely used for detection of anaplastic lymphoma kinase (ALK) gene rearrangement. Rare atypical signal pattern with reduced isolated red (RIR) ALK 3’ FISH signals was described in ALK positive non-small cell lung cancer (NSCLC).

Aims
Our aim was to examine the incidence and diagnostic significance of this unusual finding among the diagnostic samples of two routine FISH laboratories.

Method
FISH analysis with dual color ALK break apart probe and/or triple color break apart/fusion ALK-EML4 FISH test was re-examined in 996 NSCLC cases. ALK rearrangement of cases with atypical RIR signals was confirmed by next generation sequencing and ALK immunohistochemistry. The signal pattern was analyzed with ImageJ software on red channel of composite z-stack FISH images by measuring the peak and total fluorescence intensity of both the attenuated and normal red signals in 50 tumor cells of each case with RIR signals.

Results
Extraordinary RIR signals were found in three out of 59 ALK positive cases. Sequencing and positive ALK immunohistochemistry verified an existing ALK rearrangement in each of RIR signal cases. Both peak and total intensity of RIR signals was significantly decreased; in comparison with means of the non-rearranged signals the peak/total intensity means of RIR signals were reduced to 50/34%, 55/55% and 58/67% in case 1-2-3, respectively (p<0.001 for each pairwise comparison).

Conclusion
RIR is a rare and challenging signal pattern among ALK positive cases. Thus, risk of misinterpreting these true FISH positive cases is high, especially by using manual analogue fluorescent microscope without z-stacking.

Additional Information

Supervisor: Gabor Lotz
E-mail address: lotz.gabor@med.semmelweis-univ.hu
Supported by the ÚNKP-19-3-I-SE-73 New National Excellence Program of the Ministry for Innovation and Technology.

Bemutatás módja

Szóbeli

Kind

Szabad

Status

elfogadva

Accepted presentation method

szóbeli

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

2221

Start

12:05

End

12:20

Authors (legacy)

Ildikó Kocsmár1, Gábor Smuk2, Gábor Pajor2, Éva Kocsmár1, Károly Szuhai3, Tamás Tornóczky2 and Gábor Lotz1
1 2nd Department of Pathology, Faculty of Medicine, Semmelweis University, Budapest
2 Department of Pathology, Medical School, University of Pécs, Pécs
3 Department of Molecular Cell Biology, Leiden University Medical Center, Leiden