p53, bcl-2 and thymidine phosphorylase as predictive markers of chemotherapy in patients with advanced and recurrent gastric cancer.

Abstract

PURPOSE: To study the relationship between expression of p53, bcl-2, thymidine phosphorylase and Ki-67 and the response to chemotherapy and survival in patients with recurrent and advanced gastric cancer. MATERIALS AND METHODS: Protein expression was assessed immunohistochemically in 28 patients treated with 5-fluorouracil, pirarubicin and cisplatin (FAP). RESULTS: The response rate in patients positive for p53 expression was 23% compared with 47% of p53-negative patients. The response rate was also reduced from 44% in patients negative for bcl-2 protein expression to 25% in bcl-2 positive patients. Thymidine phosphorylase (dThdPase) expression was observed in 20 patients (71%), 50% of whom responded to chemotherapy, while patients negative for dThdPase expression did not respond to chemotherapy. The correlation between response rate and dThdPase-positivity was statistically significant (p < 0.05). However, with regard to patient survival, p53- and bcl-2-negative patients showed significantly better survival than patients positive for p53 and/or bcl-2 (p = 0.036). CONCLUSION: While dThdPase expression may be a useful predictor of response to chemotherapies that include 5-FU, p53 and bcl-2 expression may predict the outcome of patients with recurrent and advanced gastric cancer following chemotherapy.