Prognostic Factors and Survival in Pericardial Mesothelioma: A Systematic Review and Quantitative Analysis

Background: Primary pericardial mesothelioma (PPM) is a rare and aggressive tumor. We aimed to analyze diagnostic pathways and factors influencing survival. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines and registered in PROSPERO (CRD420261277326). MEDLINE, Web of Science, and EMBASE were searched up to March 2025. Case reports and case series published from 2010 onwards de- scribing histologically confirmed PPM were included. Data were extracted independently by multiple reviewers. Risk of bias was assessed using Joanna Briggs Institute tools. Individual patient data were pooled. Survival was analyzed using Kaplan-Meier and log-rank tests, and factors associated with survival ≥12 months were evaluated using univariable logistic regression. Results: A total of 120 patients were included (108 case reports, 4 case series). Diffuse pericardial involvement predominated (74.2%), while localized tumors occurred in 30.8%. Constrictive pericarditis was present in 31.7%. Median overall survival from diagnosis was 7.4 months (IQR 1.75–13.5). Use of CT and PET in the diagnostic process was associated with longer survival (CT: 9.1 vs. 1.5 months, p = 0.02; PET: 14 vs. 6 months, p = 0.04). Chemotherapy was associated with improved survival (OR 3.3; 95% CI 1.3–8.4; p = 0.01). Greater pericardial effusion volume was also associated with longer survival (OR 1.56; 95% CI 1.05–2.32; p = 0.028). Worse outcomes were observed in patients with constrictive pericarditis (p = 0.01) and diffuse disease (p = 0.04). Conclusions: PPM carries a poor prognosis. Chemotherapy and advanced imaging are associated with longer survival, whereas constrictive pericarditis and diffuse involvement indicate worse outcomes. Early recognition may reduce diagnostic delay. Findings should be interpreted with caution due to limitations of case-based data.