The influence of positive peritoneal cytology on survival in patients with pancreatic adenocarcinoma.
The American Joint Committee on Cancer (AJCC) staging system for pancreatic adenocarcinoma classifies positive peritoneal cytology as stage IV disease. Data are limited with respect to the prevalence of positive peritoneal cytology and its influence on survival in patients with resectable, locally advanced, and metastatic disease. Four hundred sixty-two patients underwent staging laparoscopy for pancreatic adenocarcinoma between January 1995 and December 2005. Kaplan-Meier survival comparisons were performed to evaluate the significance of positive peritoneal cytology on overall survival (OS) in resected patients and patients with locally advanced and metastatic disease. Of the 462 patients, 47% (217/462) underwent a pancreatic resection. The 21% (95/462) with locally advanced disease and 32% (150/462) with metastatic disease did not undergo resection. Peritoneal cytology was positive in 17% (77/462), and was associated with stage of disease (metastatic, 37%; locally advanced, 11%; resected, 5%; P=0.01). Positive cytology was not associated with OS in patients with metastatic disease or locally advanced disease, but was in resected patients (median, 16 months vs. 8 months; P<0.001). Node-positive disease was present in 8 of 10 patients resected with positive cytology (2 years OS, 12% positive cytology vs. 23% negative; P=0.006). In this study, patients who underwent resection in the presence of positive peritoneal cytology and absence of other identifiable metastatic disease had a similar survival as other patients with stage IV disease.