6th ESACP Congress, Heidelberg, April 7-11, 1999

A057
THE INFLUENCE OF TUMOR GRADE AND INTRAGASTRIC TUMOR LOCATION ON NUMERICAL CHROMOSOME ABERRATIONS IN PRIMARY HUMAN GASTRIC CARCINOMA
Fringes B 1, Mayhew TM 2, Reith A 3, Ward DC 4

1) Div.Molecular Pathology, Justus-Liebig-University, Giessen, Germany, 2) Biomedical Sciences, Univ. Nottingham, UK, 3) Norwegian Institute for Cancer Research, Oslo, Norway, 4) Dept.Genetics, Yale University, School of Medicine, New Haven, Connecticut, USA

Primary human gastric carcinoma remains among the leading killer cancers in most western industrial countries. In a number of moleculargenetic studies contradictory results were published when tumor histological type was the exclusive criterion of correlation with the genomic data obtained. 20 cases of gastric cancers were analyzed by fluorescent in-situ hybridization (FISH) using several centromere-specific probes, confocal laser scanning microscopy and quantitative fluorescent signal analysis. Numerical aberrations of 4 different chromosomes (Chro. 1,3,10 and 17) did not significantly correlate to the histological subtypes of the Lauren classification. However, when correlated to the WHO classification, case incidence with polysomic changes for chromosomes 1 and 17 increased with histological tumor grade. In addition case incidence with chromosome 1 and 17 aneusomic copy numbers correlated with tumor location in the upper part of the gastric wall, i.e. tumor closeness to the cardia-oesophageal junction. We conclude that numerical chromosome changes in primary human gastric cancer are dependent on the grade of tumor differentiation and obviously on the localization of the neoplasms within the gastric wall. This correlates to clinical observations, showing worse prognostic outcome for gastric cancers located at the cardia.