PROGNOSTIC-SIGNIFICANCE OF DNA-PLOIDY IN ADENOCARCINOMA OF THE PANCREAS - A FLOW CYTOMETRIC STUDY OF PARAFFIN-EMBEDDED SPECIMENS

Background. The prognostic significance of tumor DNA ploidy in patient s with cancer of the pancreas has not been defined because conflicting results have been reported. Methods. DNA content was measured in 56 d uctal adenocarcinomas of the pancreas. DNA ploidy status was evaluated by flow cytometry in nuclei isolated from paraffin-embedded tumor tis sues. Results. An abnormal DNA stemline was observed in 27 (48%) patie nts. The percentage of aneuploid tumors was significantly increased in tumors classified as Stage III/IV (53%) compared with those classifie d as Stage I (22%). A borderline significant association existed betwe en DNA ploidy and radicality of surgery (P = 0.08). The median surviva l of patients with diploid carcinomas was 6.9 months (standard error, +/- 0.9) in comparison to 4.5 +/- 1.2 months for patients with aneuplo id tumors (P = 0.013 by generalized Wilcoxon test; P = 0.023 by genera lized Savage test). Although a selection bias cannot be excluded, surv ival of patients with a radical resection was longer than that of pati ents with a nonradical resection (P 0.0008 and P = 0.0085, respectivel y). In addition, presence of distant metastasis (P - 0.0006 [Wilcoxon test] and P = 0.033 [Savage test]) could be identified as a prognostic factor. In a Cox regression model, results of surgery and DNA ploidy were independent prognostic variables. Conclusions. Because DNA ploidy has a significant impact on prognosis in pancreatic cancer, it should he used as a variable for stratified randomization of patients in the rapeutic trials.