Factors affecting prognosis in patients diagnosed with epithelioid pleural mesothelioma who underwent surgery.

Background: To examine how pathological variables affect prognosis in patients undergoing surgery for epithelioid pleural mesothelioma (PM). Methods: The study examined 64 patients treated surgery for PM between January 2007 and October 2019, retrospectively. Clinicopathological variables including age, surgical procedure, tumor stage, and detailed histopathological features (nuclear atypia, mitotic count, necrosis, nuclear grading, and tumor grade) were evaluated. Overall survival was analyzed using Kaplan-Meier and Cox proportional hazards regression models. To avoid multicollinearity among interrelated pathological parameters, two separate multivariate Cox models were constructed. Results: The 5-year survival rate was 8 percent, compared to 62 percent in the first year. Individuals 65 and older had no 5-year survival, whereas patients 65 and younger had a rate of 11 percent (p=0.046). In comparison to groups with mild and moderately high mitotic scores, those with a high mitotic score (p=0.019) had significantly lower median survival and 5-year survival rates. Variables (p<0.15) included in the univariate survival analysis were patients who 65 years and older, type of operation, mitosis, necrosis, tumor stage, nuclear grading, and grade of mesotheliomas. In multivariate analysis, high nuclear grade (Model 1: Hazard ratio [HR]=2.48, 95% confidence interval [CI]: 1.09-5.62, p=0.030) and high tumor grade (Model 2: HR=2.36, 95% CI: 1.05-5.31, p=0.037) were independently associated with worse overall survival. Conclusion: Pathological grading, represented by either nuclear grade or tumor grade, is the strongest independent prognostic factor for survival in patients with epithelioid PM.