[p53 and Bax protein expression as predictor of chemotherapeutic effect in gastric carcinoma]

This study was performed to estimate p53 and Bax overexpression as a predictor of the response to chemotherapy of patients with gastric cancer. The subjects were 20 patients with stage IV gastric cancer and 3 with locally recurrent lesions treated with 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) for 4 weeks. Of the total 23 patients, there were 10 responders: 2 showing complete response (CR) and 8, partial response (PR). Carcinoma biopsy specimens of all were obtained endoscopically with anti-p53 and anti-Bax antibodies. Of the 10 responders, 7 were in the negative p53 staining group, while of the 13 non-responders, 11 were in the positive p53 staining group (p = 0.013). But no correlation was demonstrated between the chemotherapeutic effect and Bax staining alone. Moreover, among the p-53-positive cases, the patients with Bax-negative tumors were all chemoresistant. Therefore, immunohistochemical identification of p-53 and Bax prior to chemotherapy may be a useful predictor for choice of non-responders to chemotherapy.