p53 expression affects the efficacy of adjuvant chemotherapy after resection of invasive ductal carcinoma of the pancreas.
p53 tumor suppressor gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair, suggesting its involvement in the mechanisms of drug resistance or chemosensitivity. The present study assessed the implication of p53 expression in the prognosis of patients and the efficacy of adjuvant chemotherapy for resectable invasive ductal carcinoma (IDC) of the pancreas. A total of 58 patients with primary IDC of the pancreas underwent pancreatectomy between 1982 and 1996: 28 patients received surgery alone and 30 patients received postsurgical adjuvant chemotherapy. p53 protein was stained immunohistochemically with anti-p53 monoclonal antibody. p53 was positively expressed in 29 out of 58 primary lesions (50%), and the survival curve of the patients with p53 (+) pancreatic cancer is lower than that of those with p53 (-) cancer. On the other hand, the survival curve of adjuvant chemotherapy group was also higher than that of surgery alone group, and furthermore, in patients with p53 (+) cancer, the survival curve of adjuvant chemotherapy group was significantly better than that of the surgery alone group. A multivariate analysis showed that p53 expression or adjuvant chemotherapy is not a significant risk-factor for prognosis, but that adjuvant chemotherapy is a significant risk factor for the patients with p53 (+) pancreatic cancer, which suggests that p53 expression affects the efficacy of chemotherapy. p53 expression may be beneficial as an indicator for introduction of adjuvant chemotherapy in pancreatic cancer patients.