A possible correlation between p53 overexpression and prognosis after radiotherapy combined surgery for rectal carcinoma

Abstract

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 surgery more than 5 years previously and whose prognosis had been recorded. Eighteen of 58 (31%) cases showed pS3 overexpression. Clinicopathological variables other than pathological T stage did not correlate with p53 expression. The proportion of residual tumor cells in p53 positive group was significantly higher than that in the negative group. Survival time was significantly shorter in p53 positive than in p53 negative patients (p = 0.0042). The proportion of cumulative local recurrence in the p53 negative group was 2.8%, while that of the p53 positive 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 distant recurrence cases was significantly higher than that without recurrence (p < 0.0001, p = 0.0016) respectively. These results suggest that p53 overexpression might predict a poor outcome at the resection of the irradiated rectal carcinoma.