Ki-ras point mutation and p53 expression in human pancreatic cancer: a comparative study among Chinese, Japanese, and Western patients.

The aim of this study was to clarify features of Ki-ras point mutation (PM) and p53 expression in Chinese pancreatic cancer and to compare those with that in other countries. Dot blot hybridization and immunohistochemical methods were performed in 59 Chinese patients. The results showed that Ki-ras PMs at codon 12 and p53 expression were frequent in this group. No relationships were found between Ki-ras PM alone and p53 expression alone, and clinicopathological parameters, including age, gender, clinical stage, and histological grade and classification in Chinese patients. However, their cooperation was significantly associated with a poor prognosis in this group. Comparison showed that there were significant differences in the overall frequency and substitution of Ki-ras PM and in the ratio of transition:transversion in pancreatic cancer among various countries. In addition, the effect of Ki-ras PM and p53 expression on a poor prognosis of pancreatic cancer may be different among various countries. These findings suggested that not only Ki-ras PM and p53 expression are frequent in Chinese pancreatic cancer, but also a gene component to pancreatic cancer may be different between Asian and Western pancreatic cancer. In addition, it seems that cooperation of Ki-ras PM and p53 expression may predict a poor prognosis in Chinese patients with pancreatic cancer.