The fate of patients with potentially resectable carcinomas is not only determined by the pTNM tumor stage, but also possibly by tumor-biological factors. The aim of this study was to identify these prognostic factors in patients undergoing primary curative (R0) resection. The study retrospectively analyzed 113 patients with ductal adenocarcinoma who were operated on between 1986 and 1995. R0 resection was able to be performed in 93 patients. Lymph node metastases were found in 73%. The rates of lymph vessel and perineural invasion were 83.5% and 45%, respectively. Among the 25 carcinomas without lymph node metastases, 64% already had lymph vessel invasion and 48% had perineural invasion. The cumulative 5-year survival rate of the 91 surviving patients analyzed was 10.5%. Depending on the tumor stage we found a significant difference in 5-year survival rates between patients without lymph node metastases (26.5%) and those with lymph node involvement (5%) (P = 0.008). A multivariate analysis only identified lymph vessel invasion (L0/1), tumor size (< or = or < or =2 cm), and tumor grading (G) to have significant and independent prognostic value. Lymph vessel invasion, tumor size, and tumor grading proved to be independent factors determining long-term prognosis.