Risk of peritoneal carcinomatosis by endoscopic ultrasound-guided fine needle aspiration for pancreatic cancer.

Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an accurate method for cytological confirmation of pancreatic malignancy, but peritoneal dissemination caused by EUS-FNA could be a matter of concern because it may lead to poorer prognosis. Our aim was to estimate the risk of peritoneal carcinomatosis by EUS-FNA for pancreatic cancer.
Methods: Two hundred and seventeen patients with cytopathologically proven pancreatic cancer in a tertiary referral center were retrospectively reviewed. They were divided into two groups: 161 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) alone (ERCP group), and 56 patients who had ever undergone EUS-FNA (EUS-FNA group). Peritoneal carcinomatosis was diagnosed by computed tomography and/or cytology during follow-up. Hazard ratios of factors including EUS-FNA for the development of peritoneal carcinomatosis were analyzed by the Cox proportional hazard model.
Results: There was no significant difference in baseline characteristics between ERCP and EUS-FNA groups. Peritoneal carcinomatosis developed in 14.9 % (24/161) during an average follow-up period of 545 days, and 17.9 % (10/56) during 599 days among ERCP and EUS-FNA group, respectively. The EUS-FNA was not identified as a significant risk factor with hazard ratios (HR) of 1.07 [95 % confidence interval (CI) 0.51-2.25, p = 0.85] by univariate analysis and 1.35 (95 % CI 0.62-2.95, p = 0.45) by multivariate analysis. Nodal involvement (HR 2.19, 95 % CI 1.03-4.63, p = 0.04) and non-resection (HR 2.64, 95 % CI 1.11-6.25, p = 0.03) were shown to be statistically significant risk factors by multivariate analysis.
Conclusions: EUS-FNA for pancreatic cancer did not significantly increase the risk of peritoneal carcinomatosis.