Apoptosis and apoptosis-associated gene products related to the response to neoadjuvant chemotherapy for gastric cancer.

To evaluate the effect of neoadjuvant chemotherapy on gastric cancer, we examined the correlation between induction of apoptosis and expression of p53, Bcl-2, and Bax. Eighty-five patients with advanced gastric cancer were retrospectively divided into the following two groups: 54 patients received 5-fluorouracil (5-FU) at 300 mg/body/day for 14 days and cisplatin (CDDP) at 15 mg/body/day for 2 days as group A; 31 patients without any preoperative chemotherapy as group B. According to histological changes in tumors due to neoadjuvant chemotherapy, the therapeutic effects on tumors were evaluated. The apoptotic index (AI) of group A was significantly higher than that of group B (1.12+/-0.40 vs. 0.67+/-0.24; p<0.01). In group A, the AI of p53-positive cases was significantly lower than that of negative cases (0.92+/-0.32 vs. 1.39+/-0.32; p<0.01). The AI of histological responders was significantly higher than that of non-responders (1.34+/-0.35 vs. 1.02+/-0.38; p<0.01). There was no significant correlation between AI and expression of Bcl-2 or Bax. In group A, histological responders, Bcl-2 positive, and high AI patients had better prognosis, respectively. In conclusion, neoadjuvant chemotherapy for gastric cancer enhanced induction of apoptosis, and AI might be useful to evaluate the effect of neoadjuvant chemotherapy.