The prognostic value of the immunohistochemical expression of p53 was evaluated in 133 patients with pancreatic cancer. Formalin-fixed paraffin-embedded specimens of ductal pancreatic adenocarcinomas retrieved at the time of operation were stained with the monoclonal antibody DO-7. Approximately half of the tumors (47%) showed a high level of p53 immunoreactivity (> or = 20% positive nuclei). No correlation was demonstrated between the level of p53 immunoreactivity and age of the patient, gender, TNM stage, resectability or site of the tumor. A high level of p53 staining was seen in a slightly smaller proportion (30%) of patients with well-differentiated tumors than in patients with moderately (50%) or poorly differentiated (50%) tumors, but the difference was not significant. In a multivariate survival analysis, stage, grade and postoperative chemotherapy emerged as independent prognostic factors. Surgical resectability, if entered instead of stage as a variable in a separate Cox model, predicted prognosis independently. In univariate analysis, the site of the tumor was also a significant prognostic variable. However, no association between the level of p53 immunoreactivity and survival in either uni- or multivariate analysis was found.