PhD Scientific Days 2020

Pathology and Oncology II. Lectures

Microscopic Gastrointestinal Stromal Tumors next to Gastric Adenocarcinoma – Coincidence or Common Molecular Pathomechanism?

Előadó neve

Dr. Kocsmár, Éva

Előadó munkahelye

2nd Department of Pathology, Semmelweis University

Előadó telefonszáma

+36 30 581 9025

Előadó e-mail címe

evakocsmar9@gmail.com

Az előadás címe

Microscopic Gastrointestinal Stromal Tumors next to Gastric Adenocarcinoma – Coincidence or Common Molecular Pathomechanism?

Szerző(k) neve és munkahelye

Éva Kocsmár, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Ildikó Kocsmár, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Luca Szalai, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Gábor Lendvai, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Attila Szijártó, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
Zsuzsa Schaff, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
András Kiss, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Ilona Kovalszky, 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
Gergely Papp, 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
Gábor Lotz, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary

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: Gastrointestinal stromal tumors (GISTs) are the most common tumors in the digestive tract arising from the mesenchymal components of the tissue. Small subtype of GISTs (micro-GIST, MG) are usually asymptomatic and most frequently found in gastric surgical specimens of patients suffering from gastric cancer. Background of the frequently occurred coincidence is still an open question.

Aims: Our aim was to investigate molecular pathomechanisms of both tumors to find similarities in their development at the mutational level.

Method: Nine cases including both gastric adenocarcinoma and MG were selected between 2002 and 2018 from the register of the 2nd Department of Pathology. Direct sequencing of KIT (exons 9, 11, 13, 14, 17) and PDGFRA (exons 18, 10, 12, 14), Epstein-Barr virus PCR and mismatch repair (MMR) immune panel, CD117, CD34 and DOG1 immunohistochemical analyses were performed on both tumors. Gastric cancers were classified according to TCGA subgroups.

Results: Prevalence of synchronous MG in gastric cancer specimens was 1.5% (10/665). All of the MGs were of spindle cell variant and immunohistochemically positive with CD117, CD34 and DOG1. All adenocarcinomas were negative for CD117 and CD34 while positive DOG1 immunostain was detected in four cases. Four GISTs carried mutations in KIT (exon 9, exon 13 and two cases in exon 11) while two further cases in PDGFRA (both of them in exon 18). None of the synchronous adenocarcinomas carried mutations in KIT or PDGFRA.
Regarding the MSI status of the synchronous tumors, MMR immune panel identified the gastric cancer component of one case as microsatellite unstable tumor. Neither the adenocarcinomas nor the MGs were positive with EBV PCR.
Considering the TCGA classification of gastric cancer, one case is in the MSI group, three cases are in the genomically stable group since five cases showed chromosomal instability.

Conclusion: This study comprehensively characterized 9 MGs and gastric cancers present in the same surgical specimen analyzing the markers of GISTs, the KIT/PDGFRA status and EBV/MSI status on both tumor types. Incidence of MGs in gastrectomy specimens was lower in our cohort than in other studies. Although a common carcinogenic effect cannot be ruled out, our data suggest that distinct mechanisms play role in the development of synchronous MGs and gastric cancers.

Additional Information

Supervisor: Dr. Gábor Lotz
Email-address: lotz.gabor@med.semmelweis-univ.hu

Supported by the ÚNKP-19-3-I-SE-65 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

2223

Start

12:35

End

12:50

Authors (legacy)

Éva Kocsmár, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Ildikó Kocsmár, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Luca Szalai, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Gábor Lendvai, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Attila Szijártó, 1st Department of Surgery, Semmelweis University, Budapest, Hungary
Zsuzsa Schaff, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
András Kiss, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary
Ilona Kovalszky, 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
Gergely Papp, 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Budapest, Hungary
Gábor Lotz, 2nd Department of Pathology, Semmelweis University, Budapest, Hungary