The Relationship Between Pleural Effusion and Malignant Pleural Mesothelioma

Pleural effusion may serve as an independent prognostic factor in patients with malignant pleural mesothelioma (MPM), according to findings from a recent study published in Scientific Reports.

The study was conducted by a team of investigators from Sichuan University in Sichuan, China. They explained that it was important to perform this research because most patients with MPM experience pleural effusion, but the impact of pleural effusion on the outcomes of patients with MPM “remains controversial.”

The researchers searched the Surveillance, Epidemiology, and End Results (SEER) database for eligible patients, as well as to collect “clinicopathological information and outcomes.” To evaluate the correlation of pleural effusion with overall survival (OS) and cancer-specific survival (CSS), the investigators used Cox proportional hazard regression analyses.

From 2000 to 2021, 4,158 patients were selected for evaluation, with a median age of 73 years. Most of the patients selected for the study were male, and the “main histological subtype” within the cohort was epithelioid MPM.

Through univariate Cox regression, correlations were identified between pleural effusion, sex, age, histology, marital status, stage, and treatment, both with OS and CSS. Moreover, pleural effusion was observed to be “independently associated with poorer OS and CSS in patients with MPM, regardless of age, sex, histology, stage, and treatment.”

Additional subgroup analyses indicated that pleural effusion has a “remarkable impact” on patients receiving surgery as part of their treatment. Because of this impact, the investigators emphasized that patients who are undergoing surgery for MPM “should receive increased attention.”

Although future studies should be conducted to validate these findings, the researchers concluded that pleural effusion “might serve as an independent prognostic factor in patients with MPM.” They also recommended additional research on the effect of pleural effusion in other clinical settings, such as immunotherapy.

Reference

Wang H, Yang R, Liu D, Li W. The presence of pleural effusion is an independent prognostic factor in patients with malignant pleural mesothelioma. Sci Rep. 2025;15:392.  doi: https://doi.org/10.1038/s41598-024-84108-6