Predictors of trimodality therapy and trends in therapy for malignant pleural mesothelioma.

Objectives: Malignant pleural mesothelioma is an aggressive and rare malignancy that frequently recurs despite aggressive therapy. We evaluated the frequency of treatment with surgery, radiation or chemotherapy, changes in therapy and survival over time and factors associated with the receipt of trimodality therapy.
Methods: The National Cancer Database (NCDB) was used to query patients with histologically proven malignant pleural mesothelioma (2004-14). Treatment over time was evaluated using the Armitage trend test. Factors associated with the receipt of trimodality therapy were analysed using logistic regression.
Results: Among 20 561 patients, only 4028 (20%) underwent cancer-directed surgery; 533 (2.6%) of whom received trimodality therapy. From 2004 to 2014, the use of surgery with chemotherapy increased 87% (P < 0.01), with no statistically significant change in the use of trimodality therapy. Median survival also increased from 8 months to 11 months (P < 0.01). Patients who were treated at an academic centre or who travel >26 miles for treatment were more likely to undergo trimodality therapy. Additional factors associated with the receipt of trimodality therapy include age less than 70, Charlson comorbidity score of 0 and presence of private insurance.
Conclusions: Many malignant pleural mesothelioma patients are not treated with trimodality therapy, with significant variation in treatment patterns. Referrals to high-volume and specialized centres may help offer more therapeutic options and trial or registry enrolment.