The presence of pleural effusion is an independent prognostic factor in patients with malignant pleural mesothelioma

Our plain-English summary of The presence of pleural effusion is an independent prognostic factor in patients with malignant pleural mesothelioma, by H. Wang, R. Yang, D. Liu, et al (Scientific Reports, 2025).

The study

• Authors: H. Wang, R. Yang, D. Liu, W. Li
• Journal: Scientific Reports
• Published: 2025;15(1):392
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) is a rare form of thoracic malignancy with a poor prognosis. Pleural effusion (PE) occurs in the majority of patients with MPM; however, its impact on MPM outcomes remains controversial. We searched for eligible patients from the Surveillance, Epidemiology, and End Results (SEER) database, and clinicopathological information and outcomes were collected. Cox proportional hazard regression analyses were utilized to evaluate the association of PE and other factors with overall survival (OS) and cancer-specific survival (CSS) in patients with MPM. A total of 4185 patients were extracted from the SEER database from 2000 to 2021. The median age of the cohort was 73 years, with a predominance of male patients and epithelioid MPM as the main histological subtype. Univariate Cox regression revealed associations between PE, age, sex, marital status, histology, stage, and treatment with both OS and CSS. Besides, multivariate analyses indicated that PE was independently associated with poorer OS and CSS in patients with MPM, regardless of age, sex, histology, stage, and treatment. Subgroup analyses suggested that PE has a remarkable impact on patients undergoing surgery. PE might serve as an independent prognostic factor in patients with MPM, especially in surgery recipients. Consequently, the development of pleural effusion in these patients should receive increased attention. Future studies are needed to validate these findings, particularly concerning the effect of PE in other clinical settings, such as immunotherapy.

© 2024. The Author(s).

In plain English

This was a retrospective study of adults with malignant pleural mesothelioma (MPM) drawn from the SEER cancer registry database (17 Registries, 2000 to 2021). It asked whether pleural effusion, meaning fluid around the lung, was linked to survival. Of 4,185 patients included, 3,661 had pleural effusion and 524 did not. The median age was 73. Asbestos exposure was not among the information collected. Five-year overall survival was 5.87% in patients with effusion and 10.80% in those without. After adjusting for age, sex, marital status, histology, stage and treatment, effusion was associated with worse overall survival (hazard ratio 1.20, 95% CI 1.08 to 1.33) and worse cancer-specific survival (hazard ratio 1.25, 95% CI 1.12 to 1.39). In patients who had surgery, the overall-survival hazard ratio was 1.37 (95% CI 1.12 to 1.68). In patients without surgery, the effect was not statistically significant. The authors concluded that effusion could serve as an independent prognostic factor, especially in surgery patients. They noted that the registry lacked data on effusion treatments, the timing of effusion and treatment combinations.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective cohort study using registry data (SEER database), analysed with Kaplan-Meier curves and Cox proportional hazards regression, plus subgroup analyses
• Who was studied: 4,185 patients aged 18 or older with microscopically confirmed malignant pleural mesothelioma in the SEER 17 Registries, 2000 to 2021: 3,661 with pleural effusion and 524 without. Median age was 73 years, and most patients were male. 14,488 cases were identified at first and 10,303 were excluded.
• Exposure: The factor studied was the presence of pleural effusion, defined by the SEER variable 'Pleural Effusion Recode (2010+)', which was based on imaging and pleural fluid evidence. Asbestos or other fiber exposure was not studied.
• Main results:
  • Five-year overall survival was 5.87% in patients with pleural effusion and 10.80% in patients without. Five-year cancer-specific survival was 7.33% and 14.20% in the same two groups.
  • In the unadjusted (univariate) analysis, pleural effusion was associated with worse overall survival: HR 1.13, 95% CI 1.02 to 1.25, p = 0.019.
  • In the multivariate analysis (adjusted for age, sex, marital status, histology, stage, surgery, radiotherapy and chemotherapy), pleural effusion was associated with worse overall survival (HR 1.20, 95% CI 1.08 to 1.33, p less than 0.001) and worse cancer-specific survival (HR 1.25, 95% CI 1.12 to 1.39, p less than 0.001).
  • Among patients who received surgery, pleural effusion was associated with worse overall survival (HR 1.37, 95% CI 1.12 to 1.68, p = 0.002, p for interaction 0.029) and worse cancer-specific survival (HR 1.44, 95% CI 1.16 to 1.79, p = 0.001, p for interaction 0.029). In patients not receiving surgery, the effect was not statistically significant.
  • Patients who did not receive radiotherapy appeared more affected by pleural effusion, but the interaction was significant only for overall survival.
  • In patients with fibrous histology (the SEER term for forms of sarcomatoid mesothelioma), the overall-survival HR for pleural effusion was 1.40 (95% CI 1.11 to 1.77). This did not differ significantly from the other histological subgroups (p for interaction 0.258).
  • Compared with the group without effusion, the pleural effusion group had more males and more epithelioid histology, and fewer patients who received radiotherapy.
• The authors' conclusion: The authors concluded that pleural effusion could serve as an independent prognostic factor in MPM and that patients receiving surgical resection may be especially affected. They stated that monitoring and managing effusion are crucial, and that prospective studies are needed on its impact in systemic therapies such as checkpoint inhibitors.
• Limitations the authors state:
  • The study was retrospective, although the authors considered the sample large and the groups balanced.
  • Some covariates could not be analysed for lack of data, such as treatment combinations and whether treatment was adjuvant or neoadjuvant.
  • Effusion-specific treatments (talc, video-assisted thoracoscopic surgery, indwelling catheter) and the timing of the effusion relative to treatment were not available in the SEER database.
  • The effect of pleural effusion in patients receiving immunotherapy could not be analysed because SEER lacks this information.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Effusion, Pleural Mesothelioma, Prognosis, Epidemiology, SEER, Overall Survival, Epithelioid, Histological Subtype.

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• Prognostic factors in patients presenting with pleural effusion revealing malignancy — S. Anevlavis, G. Kouliatsis, et al. (2014)
• Prognostic factors for survival after surgical palliation of malignant pleural effusion — J.E. Pilling, M.E. Dusmet, et al. (2010)
• Angiogenesis is an independent prognostic factor in malignant mesothelioma — J.G. Edwards, G. Cox, et al. (2001)
• Aquaporin 1 is an independent prognostic factor in pleural malignant mesothelioma — S.C. Kao, N. Armstrong, et al. (2012)
• Ki67 index is an independent prognostic factor in epithelioid but not in non-epithelioid malignant pleural mesothelioma: a multicenter study — B. Ghanim, T. Klikovits, et al. (2015)

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