Clinical implications of peritoneal cytology in potentially resectable pancreatic cancer: positive peritoneal cytology may not confer an adverse prognosis.

Abstract

To determine the value of peritoneal washing cytology (CY) in determining resectability of pancreatic cancer. CY has been used widely in the diagnosis and staging of several cancers. However, its predictive value in identifying potentially resectable pancreatic cancer is undetermined. Peritoneal washing samples were collected from 233 patients with pancreatic cancer between June 1991 and August 2006. A total of 157 patients had resectable and 76 had unresectable lesions. Correlations between CY status and clinicopathologic parameters with overall survival rates were analyzed. Malignant cells were identified in samples from 21 patients (13.4%) with resectable tumors and 27 patients (35.5%) with unresectable tumors. CY+ was more frequent in large tumors (> or =2 cm) than small tumors (<2 cm; P = 0.034). CY status did not correlate with any other clinicopathologic parameter. The overall survival of CY+ patients was worse than that of CY- patients (P = 0.047). Median survival following resection was 13.6 months for CY+ patients and 13.5 months for CY- patients. Among the patients who had unresectable lesions, median survival time was 5.9 months for CY+ and 6.1 months for CY- patients. However, among CY+ patients, those who underwent resection lived longer than those who did not (P = 0.019). Cytologic status has little predictive value for survival, and patients whose pancreatic cancer would otherwise be considered resectable should not be denied curative resection solely because they are CY+.