Jennifer L Beebe-Dimmer, Jon P Fryzek, Cecilia L Yee, Tapashi B Dalvi, David H Garabrant, Ann G Schwartz, Shirish Gadgeel

Mesothelioma is a rare malignancy typically associated with exposure to asbestos and poor survival. The purpose of this investigation was to describe mesothelioma patient characteristics, treatment patterns, and overall survival (OS) utilizing the National Cancer Institute's Surveillance, Epidemiology, and End Results-Medicare database. Patients in this study were diagnosed with malignant mesothelioma of the pleura or peritoneum between January 1, 2005 and December 31, 2009 with follow-up for survival through December 31, 2010. We examined both patient and tumor characteristics at time of diagnosis and subsequent treatment patterns (surgery, radiation, and chemotherapy). Among patients treated with chemotherapy, we determined chemotherapy regimen and OS by line of therapy. Of the 1,625 patients considered eligible for this investigation, the median age at diagnosis was 78 years. Nearly a third of patients (30%) had surgery as part of their treatment and 45% were given chemotherapy. The median OS was 8 months (range 1-69 months). Among chemotherapy patients, the most commonly (67%) prescribed regimen for first-line therapy was cisplatin or carboplatin (Ca/Ci) combined with pemetrexed (Pe). Among those prescribed Ca/Ci + Pe as first-line therapy, retreatment with Ca/Ci + Pe (28%) or treatment with gemcitabine (30%) were the most common second-line therapies. Median OS for those receiving first-line chemotherapy was 7 months, and among those receiving second-line therapy median OS was extended an additional 5 months. Irrespective of surgical resection, mesothelioma patients receiving some form of chemotherapy survived longer than patients who did not, with an additional survival benefit among those patients receiving multimodal treatment.