C-myc amplification and cluster analysis in human gastric carcinoma

The tumour samples of 23 patients (9 male, 14 female, aged 25-85) were rand omly selected for the study. DNA was isolated fi om paraffin embedded tissu e for quantitative dot-blot hybridization, in order to determine the amplif ication values for the c-myc and k-ras oncogenes. The clinical and histolog ical parameters studied were as follows: grade, TNM staging system, Lauren' s histological type, localization and the severity bf the disease. Amplifie d c-myc was found in 6 cases. Amplification was concomitant with c-myc over expression detected with immunohistochemical staining The amplification - 9 .1-fold on the average (ranging from 2.12 to 18.2) was significantly associ ated with the presence of distant metastasis (corr. coeff: 0.5623, p<0.01), but with none of the other parameters. No case with K-ras amplification wa s recorded. The result of the multivariate cluster analysis proved that age was the decisive factor in the segregation process. This age-related distr ibution (69 vs. 40, p<0.001), however; did not coincide with either the inc idence of distant metastasis ol c-myc amplification.