Prognostic Value of Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma Stratified by the Resectability Status.

BACKGROUND The prognostic value of peritoneal lavage cytology (CY) for pancreatic ductal adenocarcinoma (PDAC) remains controversial. We assessed the prognostic impact of CY status stratified by resectability in PDAC patients treated with surgical resection. METHODS Clinical data from 440 patients with PDAC who underwent surgical resection were retrospectively analyzed to examine the association of CY status with clinicopathological factors and survival. RESULTS Positive CY status (CY+) was found in 30 patients (7%). These patients had significantly worse overall survival in both the resectable (R) (P = 0.002) and borderline resectable (BR) (P < 0.001) groups. The median survival time of CY+ patients in the R and BR groups was 25.6 and 6.7 months, respectively. Multivariate analysis revealed that CY+ was an independent prognostic factor in the BR group (P < 0.001) but not in the R group (P = 0.08). In the R group, CY+ patients who received adjuvant chemotherapy had significantly longer overall survival than those without adjuvant chemotherapy (34.3 vs. 9.8 months, respectively; P < 0.001). CONCLUSIONS The prognosis of CY+ patients in the BR group was extremely poor. In the R group, surgical resection combined with adjuvant chemotherapy may improve the prognosis of CY+ patients.