Incidence and risk factors for peritoneal carcinomatosis following open radical cystectomy

To characterize the frequency and risk factors of peritoneal carcinomatosis (PC) in patients undergoing open radical cystectomy (RC).

We identified 3,285 patients with urothelial carcinoma treated with RC for curative intent between 1980 and 2016. At last follow-up, 72.1% (2,370/3,285) of patients had died, with a median follow-up of 8.6 years (Interquartile Range, (IQR) 3.7, 14.1). PC was defined as any recurrence involving the omentum, small bowel, and mesentery. Overall-specific survival (OSS) and cancer-specific survival (CSS) was evaluated using Kaplan-Meier methodology and log-rank test. Risk factors for mortality and recurrence were performed using Cox proportional hazards regression models.

One hundred and twenty nine (3.9%) patients were diagnosed with PC, while a total of 1,148 (34.9%) patients experienced recurrence at other sites. Median time to PC vs. other-site recurrence was 1.3 (IQR 1.3, 2.3) and 0.9 (IQR 0.5, 2.1) years, respectively (P= 0.04). Only increasing pathologic stage on multivariable analysis was associated with developing PC (pT1 HR 2.51, 95CI 1.14-5.55, P= 0.02; pT2 OR 2.82, 95CI 1.47-5.43, P= 0.002; pT3+ 2.40, 95CI 1.31-4.42, P= 0.005) over other recurrence patterns. Nodal status and tumor margin status were not associated. Patients with PC experienced worse OSS and CSS than other types of recurrence (P< 0.001).

PC was identified in almost 4% of patients undergoing open RC. PC is a rare occurrence after RC and primarily impacts patients with locally advanced disease.