Disparities in Compliance With National Guidelines for the Treatment of Malignant Pleural Mesothelioma

Background: Current guidelines support cancer-directed surgery, chemotherapy, or active surveillance for clinical stages 1 to 3 of epithelial malignant pleural mesothelioma (MPM). Definitive chemotherapy is recommended for sarcomatoid/biphasic histologies. Our objective is to assess compliance with recommendations, measuring their impact on overall survival.

Methods: The National Cancer Database participant user file (2004 to 2014) was queried for patients diagnosed with MPM clinical stages 1 to 3. Multivariable logistic regression model identified factors independently associated with guideline compliance. Kaplan-Meier analysis and Cox proportional hazards were used for overall survival comparison with histologic subgroup analysis.

Results: A total of 3419 patients with clinical stages 1 to 3 met criteria for analysis and comprised epithelial (68.5%), sarcomatoid (17.2%), and biphasic subtypes (14.3%). Cancer-directed surgery was significantly underutilized in epithelial MPM, with 29.3% having no treatment. On multivariable analysis, insurance status and facility type were the strongest predictors of guideline compliance. High-volume hospitals were the most compliant with guidelines (odds ratio 3.58, 95% confidence interval (CI), 2.34 to 5.49, P < .001). Median survival estimates for no treatment, chemotherapy alone, surgery plus chemotherapy, and trimodal therapy were 10.2, 15.4, 21.1, and 21.7 months, respectively (log rank P < .001). In epithelial MPM, a significant increase in overall survival was observed in surgery plus chemotherapy (hazard ratio 0.62, 95% CI, 0.53 to 0.73, P < .001) and trimodality (hazard ratio 0.61, 95% CI, 0.49 to 0.76, P < .001; reference: no treatment).

Conclusions: There is a suboptimal compliance with national guidelines for the treatment of MPM, particularly in low-volume nonacademic settings. Adherence to recommended surgery-based multimodal therapy is associated with an overall survival improvement.