GENE AMPLIFICATION AND PROLIFERATIVE KINETICS IN RELATION TO PROGNOSIS OF PATIENTS WITH GASTRIC-CARCINOMA

BACKGROUND. The differences in survival of gastric carcinoma patients who have identical clinical or pathologic stages prompted the authors to investigate the prognostic significance of biologic features that a re known to affect the clinical aggressiveness of other tumor types. M ETHODS. One hundred twenty-four tumor samples from patients who had re ceived radical or palliative surgery were analyzed for c-myc, c-K-ras , hst, and c-erb B-2 gene amplification by means of the Southern blot technique. Of these tumors, 70 were also examined for cell kinetics by means of the thymidine labeling index (TLI). RESULTS. The analysis of associations between gene amplification and the anatomicopathologic v ariables (TNM classification, site of tumor, and histology) showed tha t amplification represents a late event in the natural history of gast ric carcinoma. Gene amplification showed a slight, statistically insig nificant, negative impact on overall survival (OS) (P = 0.09). Amplifi cation of c-erb B-2 correlated in a statistically significant way with reduced OS (P = 0.03). Cox multiple regression analysis revealed that neither c-erb B-2 amplification nor TLI had prognostic significance i n relation to OS. CONCLUSIONS. These data indicate that amplification of the examined oncogene did not reveal a new independent prognostic f actor for patients with gastric carcinoma. However, the authors' resul ts did show a strong correlation between gene amplification and tumor progression, which warrants further study involving larger series of p atients. At the same time, the TLI results underlined the need to iden tify the most suitable biologic material for use in the estimation of proliferative indexes in gastric carcinoma. (C) 1997 American Cancer S ociety.