SPONTANEOUS APOPTOSIS IN GALLBLADDER CARCINOMA - RELATIONSHIPS WITH CLINICOPATHOLOGICAL FACTORS, EXPRESSION OF E-CADHERIN, BCL-2 PROTOONCOGENE, AND P53 ONCOSUPPRESSOR GENE

BACKGROUND. Although valuable information regarding spontaneous apopto sis in various human cancers has recently been obtained, spontaneous a poptosis in carcinoma of the gallbladder has not been studied. METHODS . Apoptotic cells were visualized using the nick end labeling method i n 49 cases of gallbladder carcinoma The relationships between frequenc y of apoptosis, which was expressed as the maximal apoptotic index (MA I), and clinicopathologic factors, immunoreactivity of E-cadherin (E-C D), bcl-2 protooncogene, and p53 oncosuppressor gene were investigated . RESULTS. MAI was significantly correlated with the maximum dimension of the tumor (P = 0.020) and high T category (P = 0.034). A closer co rrelation between high MAI and high T category was observed in E-CD po sitive cases (P = 0.0035), whereas no such correlation was evident in E-CD negative cases (P = 0.536). No relationship was observed between MAI and age, sex, histology, grading, stromal volume, venous or lympha tic permeation, and lymph node status. Overexpression of bcl-2 and p53 was observed in 18.4% (9 of 49) and 34.7% (17 of 49) of the cases, re spectively, and there was a positive correlation between bcl-2 and p53 (P = 0.035). No notable relationship was observed between apoptosis a nd overexpression of bcl-2 or p53. CONCLUSIONS. These results indicate that the frequency of apoptosis may increase with the progression of gallbladder carcinoma, and in this process, cell-to-cell interaction m ay affect the cancer's capacity to undergo apoptosis. Oncogenic change s of bcl-2 and p53 may play a role in tumorigenesis of gallbladder car cinoma, but such changes were not correlated with spontaneous apoptosi s. (C) 1996 American Cancer Society.