Characteristics of Long-Term Survivors With Peritoneal Mesothelioma - Insights From the National Cancer Database

<b>Introduction:</b> Peritoneal mesothelioma (PM) is a rare cancer associated with high mortality. No studies exist using the National Cancer Database (NCDB) that have examined factors associated with long-term survival (LTS). <b>Methods:</b> NCDB 2006-2019 was queried for patients with PM. Primary objective was to determine the characteristics of LTS among patients with peritoneal mesothelioma. Secondary objective: identified predictors of LTS were then used to develop and internally validate a nomogram to predict the probability of LTS among patients. LTS was defined as 5 or more years of survival after diagnosis. Univariate and multivariate logistic analyses were performed. <b>Results:</b> The study included 3,636 patients with PM, 17.8% had LTS. The median survival time was 17.7 months. For LTS, the median survival time was ∼92 months while the median survival time of non-long-term survivors (NLTS) was 11.7 months. Following factors were common with LTS patients compared to the NLTS: female, younger, privately insured, treatment at academic/research institutions and treatment at high case volume institutions, Charlson-Deyo comorbidity score of 0, receiving radical surgery, receiving chemotherapy, greater proportion of grade 1 disease, negative lymph nodes, and lower rates of lymphovascular invasion (<i>P</i> < .001). The nomogram included age, gender, and surgical margins. <b>Conclusion:</b> A subset of PM patients can be long-term survivors with effective patient selection and appropriate care. This study highlights critical factors that influence LTS, paving the way for personalized treatment strategies and enhanced prognostication. Further research is needed to improve patient selection and ensure patients likely to be LTS receive adequate care.