Risk factors affecting prognosis in pseudomyxoma peritonei patients after hyperthermic intraperitoneal chemotherapy and cytoreductive surgery: a systematic review and meta-analysis

Objective: This study aims to identify and explore the risk factors affecting the prognosis of pseudomyxoma peritonei patients following hyperthermic intraperitoneal chemotherapy and peritoneal cytoreductive surgery. Methods: PubMed, Medline, Embase, Cochrane Library and registers were screened. The search timeframe was set before May 2025. We calculated each potential risk factor as risk ratio ( RR ) with 95% CI . Based on sample size, Egger’s P value, and heterogeneity, the evidence was classified as high quality (class I), moderate quality (Class II or III), and low quality (Class IV). In addition, meta regression and sensitivity analysis were performed to explore potential sources of heterogeneity and stability of results. Results: A total of 20 studies were included, with a total of 6612 patients. Studies with high quality (Class I) evidence showed that pseudomyxoma peritonei patients with elevated levels of CA19-9 ( RR , 2.30; 95% CI , 1.66–3.20, P = 0.00), CA125( RR , 3.39; 95% CI , 2.29–5.01, P = 0.00) had worse prognosis. Moderate quality (Class II) evidence revealed significant associations between sex ( RR , 1.73; 95% CI , 1.25–2.39, P = 0.00), CEA ( RR , 3.16; 95% CI , 1.40–7.12, P = 0.01), PCI ( RR , 1.05; 95% CI , 1.01-1.09, P = 0.03), CCS ( RR , 2.10; 95% CI , 1.61–2.76, P = 0.00), and postoperative outcomes. Moderate quality (Class III) evidence showed that ASA classification ( RR , 1.19; 95% CI , 1.06-1.35, P = 0.00) and peritoneal histopathology ( RR , 3.82; 95% CI , 2.25-6.49, P = 0.00) affected the prognosis. Studies with moderate quality (Class II) evidence showed no significant association between age ( RR , 1.015; 95% CI , 0.997-1.033, P = 0.05) and prognosis after CRS-HIPEC. Conclusion: Male, ASA classification, high grade peritoneal histopathology and PCI are patient-related risk factors for prognosis after CRS-HIPEC, CA19-9, CA125 and CEA are tumor markers that affect prognosis. CCS is a risk factor associated with surgery. This study can guide clinicians to identify high-risk patients, implement more intensive post-operative monitoring, adjust surgical and chemotherapeutic plans and customize long-term follow-up strategies to improve prognosis.