Mutations of p53 tumor suppressor gene, apoptosis, and proliferation in intrahepatic cholangiocellular carcinoma of the liver

This study was performed to examine the correlation between mutations of the p53 tumor suppressor gene, the occurrence of apoptosis, and proliferation in cholangiocellular carcinoma of the liver. The results obtained were compared with pathohistological stage (according to UICC) and grade and with disease related survival rate. In 41 curatively (R0-) resected intrahepatic cholangiocellular carcinomas, the status of the p53 gene was determined by direct sequencing of exons 4-9 and immunohistochemically. Apoptosis was assessed using the in situ end labeling (ISEL) technique in combination with morphological criteria. Proliferation was analyzed by immunohistochemistry of MIB-1 (Ki-67), Proliferating cell nuclear antigen (PCNA), and silver-stained nucleolar organizer regions (AgNOR). The results obtained were compared with pathohistological stage (according to UICC), grade, several other histopathological factors, and survival rate. Mutations of p53 were detected in 15/41 carcinomas examined (37%). The most common change was a G→C and C→T transition, changing the hot spot amino acid determined by exons 4-8. Of these 15 tumors, 14 were also p53-positive by immunohistochemistry. In each carcinoma examined, we could demonstrate MIB-1, PCNA, and AgNOR dots and also apoptotic cells in variable proportions. The proliferation markers showed a significant correlation among themselves. In univariate survival analysis, the extent of the primary tumor, lymph node status, grade, and p53 were significant factors influencing patient survival. Performing multivariate Cox regression survival analysis, however, only the extent of primary tumor and lymph node status had an independent prognostic impact. Apoptosis was not related to patient prognosis or to other parameters examined. In conclusion, these results indicated that p53 could serve as an additional prognostic parameter that could provide auxiliary information for patient outcome. However, tumor stage and lymph node involvement were the strongest prognostic factors. We failed to establish apoptosis or other pathological parameters as factors predicting the prognosis of patients with cholangiocellular carcinoma.