The tumor suppressor gene p53 has been shown to be a factor in the carcinogenesis or progression of gastric cancer. The mutant p53 has been reported to cause a higher risk of lymph-node metastasis. Futhermore, mutation of the p53 has been linked to a poor prognosis for gastric cancer. The heat shock protein-27 (HSP27), a stress protein, has also been reported to be a poor prognostic factor in ovarian and breast cancers. However, in gastric-cancer patients, controversies exist as to its influence on the prognosis. In the present study, we used an immunohistochemical stain to observe the effects of p53 and HSP27 on the clinicopathological factors and on the prognosis for gastric-cancer patients.

To evaluate the significance of p53 and HSP27 in gastric cancer patients, we analyzed 212 cases of gastric cancer (stage I~IV). Tissue samples of 212 patients were stained immunohistochemically for the mutant p53 protein and for HSP27. The correlations between protein expression and the clinicopathological factors were investigated.

The overall expression rates for p53 and HSP27 were 36.9% and 27.8%, respectively. p53 and HSP27 were correlated to each other because the HSP27 expression rate was higher in the p53-positive group (P=0.046). Statistically, the p53 and the HSP27 expression rates were significantly increased in the case of tumor invasiveness, lymphatic metastasis and vessel involvement. Therefore, they play a role in cancer progression. The 5-year survival rates of the p53-positive and the p53-negative groups were 62.8% and 60.1%, respectively (P=0.793) while the 5-year survival rates for the HSP27-positive and HSP27-negative groups were 54.2% and 63.1%, respectively (P=0.090).

p53 and HSP27 were correlated to each other in our immunohistochemical study of gastric carcinomas and they were not independent prognostic factors in gastric- cancer patients. However, further studies are needed to determine their prognostic values for gastric-cancer patients.