Retrospective cohort study on prognostic factors of malignant pleural effusion secondary to pleural mesothelioma

Our plain-English summary of Retrospective cohort study on prognostic factors of malignant pleural effusion secondary to pleural mesothelioma, by X. Qiao, J.J. Zhang, B. Liu, et al (Journal of Thoracic Disease, 2026).

The study

• Authors: X. Qiao, J.J. Zhang, B. Liu, J.W. Qin
• Journal: Journal of Thoracic Disease
• Published: 2026;18(7):731
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant pleural effusion (MPE) frequently complicates pleural mesothelioma; however, prognostic determinants for this condition, particularly pleural fluid biomarkers, have yet to be comprehensively characterized. This study sought to assess the prognostic utility of clinical profiles and laboratory findings, with a specific focus on pleural fluid parameters, in patients with mesothelioma-associated MPE.

Methods: This retrospective cohort study included patients diagnosed with MPE secondary to pleural mesothelioma at Tianjin Chest Hospital from January 2015 to May 2025. Inclusion criteria: age ≥18 years, confirmed diagnosis. Exclusion criteria: active infection, incomplete baseline clinical/laboratory data, or prior anti-tumor therapy. Follow-up was conducted via telephone at monthly intervals for 6 months then every 3 months. The primary outcome was overall survival (OS), defined as time from diagnosis to death or last follow-up. Univariable and multivariable Cox regression analyses were performed to identify independent prognostic factors.

Results: Seventy‑one eligible patients were analyzed. Median OS was 30 months (range, 16-44 months). Four factors were independently associated with OS in multivariable analysis: pleural fluid lactate dehydrogenase (LDH) ≥361 U/L [hazard ratio (HR) 4.373, 95% confidence interval (CI): 1.903-10.049, P=0.001], fibrinogen (FIB) ≥3.82 g/L (HR 3.592, 95% CI: 1.683-7.666, P=0.001), mean platelet volume (MPV) ≥12.50 fL (HR 2.507, 95% CI: 1.125-5.586, P=0.03), and absolute lymphocyte count ≥1.48×109/L (HR 0.423, 95% CI: 0.204-0.877, P=0.02).

Conclusions: These four routinely available baseline parameters-pleural fluid LDH, FIB, MPV, and absolute lymphocyte count-may serve as potential prognostic indicators in patients with MPE secondary to pleural mesothelioma. Prospective, multicenter studies with external validation are required to confirm these findings.

© AME Publishing Company.

In plain English

This single-center retrospective cohort study looked at 71 adults with malignant pleural effusion (fluid around the lung) from pleural mesothelioma at Tianjin Chest Hospital, China, January 2015 to May 2025. None had received anti-tumor treatment before. The authors tested whether routine blood and pleural fluid tests at diagnosis were linked to survival. Median overall survival was 30 months (16–44, labeled a range in the text but a 95% confidence interval in a table); 53 of 71 patients died. In the multivariable analysis, higher risk of death was linked to pleural fluid lactate dehydrogenase 361 U/L or more (hazard ratio 4.373, 95% confidence interval 1.903–10.049), fibrinogen 3.82 g/L or more (3.592, 1.683–7.666) and mean platelet volume 12.50 fL or more (2.507, 1.125–5.586). Lower risk was linked to a lymphocyte count of 1.48 × 10^9/L or more (0.423, 0.204–0.877). The 16 patients (22.5%) with a clear asbestos exposure history showed no statistically significant survival difference (hazard ratio 1.238, 0.628–2.441). The authors concluded these four tests may serve as potential prognostic indicators. They called the results exploratory, citing small sample, missing stage data and no validation.

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: Single-center retrospective cohort study (prognostic study of overall survival using univariable and multivariable Cox regression)
• Who was studied: Patients aged over 18 with malignant pleural effusion secondary to pleural mesothelioma, diagnosed and treated at Tianjin Chest Hospital, China, January 2015 to May 2025. 93 were identified and 71 were analyzed after excluding 7 with prior anti-tumor therapy, 12 with incomplete data and 3 with other primary tumors. 43 (60.6%) were male and 28 (39.4%) female.
• Exposure: The factors studied were baseline clinical features and routine blood and pleural fluid laboratory values at diagnosis. Asbestos exposure history was recorded only as yes or no (16 of 71, 22.5%, yes). No fiber types, jobs or doses were reported.
• Main results:
  • Median overall survival for the 71 patients was 30 months. The 16–44 month bounds are labeled 'range' in the article's abstract and results text but '95% CI' in Table 1.
  • 53 all-cause deaths were observed among the 71 patients.
  • Multivariable analysis: pleural fluid LDH of 361 U/L or more was associated with worse overall survival (HR 4.373; 95% CI 1.903–10.049; P=0.001).
  • Multivariable analysis: fibrinogen of 3.82 g/L or more was associated with worse overall survival (HR 3.592; 95% CI 1.683–7.666; P=0.001).
  • Multivariable analysis: mean platelet volume of 12.50 fL or more was associated with worse overall survival (HR 2.507; 95% CI 1.125–5.586; P=0.03).
  • Multivariable analysis: an absolute lymphocyte count of 1.48 × 10^9/L or more was associated with better overall survival (HR 0.423; 95% CI 0.204–0.877; P=0.02).
  • Univariate analysis: patients with a history of asbestos exposure, compared with those without, had an HR of 1.238 (95% CI 0.628 to 2.441, P=0.54). This was not statistically significant.
  • Univariate analysis: sarcomatoid histology, compared with epithelioid, had an HR of 4.394 (95% CI 1.471 to 13.110, P=0.008). It was not among the four independent factors in the multivariable model.
• The authors' conclusion: The authors concluded that pleural fluid LDH, peripheral blood mean platelet volume, absolute lymphocyte count and fibrinogen were independently associated with overall survival and may serve as potential prognostic indicators. They also concluded the findings are exploratory and need multicenter, prospective studies with external validation.
• Limitations the authors state:
  • Retrospective, single-center study with a relatively small sample size (n=71)
  • No internal validation was performed; the findings are exploratory
  • No external validation; generalizability to other populations is unknown
  • TNM stage was unavailable for most patients, so results could not be adjusted for stage
  • 28.2% of patients had unclassified histology, a major source of confounding
  • Cutoff values were chosen from the data (ROC curves), which can inflate hazard ratios and false-positive findings
  • The impact of immunotherapy could not be assessed
  • No direct comparison with the existing LENT and PROMISE prognostic scores

Topics

Medical terms in this study, explained in our Lexicon: Cohort Study, Pleural Effusion, Pleural Mesothelioma, Biomarker, Mesothelioma, Overall Survival, Lactate Dehydrogenase (LDH), Hazard Ratio.

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