Peritoneal Dissemination in Patients with Recurrence After Post-pleurectomy/decortication for Pleural Mesothelioma.

Background: In clinical practice, peritoneal dissemination after curative-intent surgery for pleural mesothelioma occasionally recurs. This study investigated the risk factors and prognosis associated with post-pleurectomy/decortication peritoneal dissemination in pleural mesothelioma, which are rarely reported. Methods: This retrospective review included 160 patients who experienced recurrence after pleurectomy/decortication for pleural mesothelioma between January 2011 and December 2021. Patients with recurrence were classified according to the initial recurrence pattern. The P group experienced recurrence with peritoneal dissemination, and the non-P group experienced recurrence without peritoneal dissemination. The analysis determined the risk factors for peritoneal dissemination using multivariable logistic regression analysis. Survival was analyzed using the Kaplan–Meier method and the log-rank test. Results: Of the 160 patients, 20 (12.5%) exhibited peritoneal dissemination and were assigned to the P group, whereas 140 (87.5%) had recurrence without peritoneal dissemination and were assigned to the non-P group. Multivariable logistic regression analysis showed that diaphragm reconstruction (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.0–8.0; p = 0.048) and female sex (OR, 3.7; 95% CI 1.26–10.8; p = 0.017) were associated with the P group. Post-recurrence survival was worse in the P group than in the non-P group (1-year post-recurrence survival: 22.2% vs. 65.3%; median: 6.7 months vs. 19.4 months; p = 0.0013). Conclusions: Peritoneal dissemination occurred in approximately one of every eight patients with recurrence after pleurectomy/decortication for pleural mesothelioma, and the incidence was significantly higher among females and patients undergoing diaphragm reconstruction. Moreover, postoperative recurrence of peritoneal dissemination was associated with a poor prognosis. [ABSTRACT FROM AUTHOR]