A POSSIBLE CORRELATION BETWEEN P53 OVEREXPRESSION AND PROGNOSIS AFTERRADIOTHERAPY COMBINED SURGERY FOR RECTAL-CARCINOMA

One hundred and twenty patients with rectal carcinoma in the lower two -thirds of the rectum were treated with preoperative radiotherapy and radical surgery between October 1986 and March 1996. The expression of p53 was examined in 58 of these patients, all of whom had undergone s urgery more than 5 years previously and whose prognosis had been recor ded. Eighteen of 58 (31%) cases showed pS3 overexpression. Clinicopath ological variables other than pathological T stage did not correlate w ith p53 expression. The proportion of residual tumor cells in p53 posi tive group was significantly higher than that in the negative group. S urvival time was significantly shorter in p53 positive than in p53 neg ative patients (p = 0.0042). The proportion of cumulative local recurr ence in the p53 negative group was 2.8%, while that of the p53 positiv e group was 43.2% (p = 0.01). The cumulative survival rate in the p53 negative group was 76.3%, while that in the p53 positive group was 24. 4% (p = 0.04). The amount of p53 positive cells in both local and dist ant recurrence cases was significantly higher than that without recurr ence (p < 0.0001, p = 0.0016) respectively. These results suggest that p53 overexpression might predict a poor outcome at the resection of t he irradiated rectal carcinoma.