Background: Several studies have reported on apoptosis and the effect of anticancer chemotherapy. Methods: We studied apoptosis induced by 5-fluorouracil (5-FU) given preoperatively to 28 patients with advanced gastric cancer and compared the findings with 101 untreated patients. The expression of bcl-2 oncoprotein, cell phase fractions, and histological chemotherapeutic effects were also compared with the apoptotic changes.
Results:
The apoptotic and S-phase fractions in 5-FU-treated patients (apoptotic fraction: 10.46 ยฑ 6.93%, S-phase fraction: 17.49 ยฑ 11.65%) were significantly greater than those in untreated controls (apoptotic fraction: 6.56 ยฑ 5.06%, S-phase fraction: 12.17 ยฑ 6.78%). A positive correlation was observed between 5-FU-induced apoptosis and accumulation of tumor cells in the S-phase fraction. There was an inverse relationship between bcl-2 oncoprotein expression and apoptosis in 5-FU-treated patients, but no significant correlation between histological effect and apoptosis. However, two patients with significant histological effects showed no bcl-2 oncoprotein expression, whereas the histological effects were mild in all the bcl-2-positive patients. Conclusions: Apoptosis may be induced by 5-FU administered preoperatively and bcl-2 oncogene expression may suppress 5-FU-induced apoptosis.