Definitive Pleural Interventions and Survival in Malignant Pleural Effusion

BACKGROUND: Malignant pleural effusions (MPE) are associated with poor prognosis. Guidelines prioritize palliation of symptoms, recommending thoracentesis, pleurodesis or indwelling pleural catheters (IPC) based on predicted survival and patient preference. However, prognosis estimation in MPE is often inaccurate, and recent studies suggest MPE is not a bystander in the broader context of oncologic disease. METHODS: Retrospective cohort study including patients with confirmed MPE who underwent definitive pleural interventions [talc poudrage by medical thoracoscopy (MT), talc slurry following chest tube drainage (CTD), or IPC placement] at a tertiary hospital between 2012 and 2022. RESULTS: Two hundred fifty-four out of 783 MPE patients (32.4%) received definitive pleural treatment modalities-MT in 106 (41.7%), CTD in 98 (38.6%), and IPC in 50 (19.7%) patients. The overall relapse rate was 52.8%, with a median time from definitive treatment to effusion relapse of 29 days, significantly different between modalities (P<0.001). Overall mortality was high (89.8%), with a median overall survival (OS) of 172 days, significantly different between interventions (P<0.001). Median survival varied significantly according to the result of pleurodesis (P<0.001). In a multivariate regression model adjusting for time from MPE diagnosis to treatment, systemic therapy, radiologic presentation and ECOG-PS, successful pleurodesis remained an independent predictor of improved OS (P<0.001). Postpleurodesis survival was more than 3-times higher in the successful pleurodesis subgroup (P<0.001). CONCLUSION: This study suggests the impact of definitive pleural interventions goes beyond the palliation of symptoms, with successful pleurodesis remaining a significant predictor of improved survival regardless of performance status and systemic cancer treatments.