Pemetrexed in malignant pleural mesothelioma and the clinical outcome.

Introduction: Pemetrexed has emerged as standard chemotherapy for malignant pleural mesothelioma (MPM). Objectives: MPMs at two Finnish University Hospitals during 7 years (2000-2006) were reviewed in order to evaluate the treatments, survival and prognostic factors. The results in two periods (before pemetrexed use in 2000-2002 and with pemetrexed in 2003-2006) were compared. Methods: Data were collected from the individual patient records retrospectively, and analysed. Results: Altogether 197 patients were diagnosed with following histologies: 136 (69%) epithelioid, 19 (10%) sarcomatoid, 17 (9%) mixed, 25 (13%) not specified; 141 (72%) patients received treatment (five extrapleural pneumonectomy, 36 pleurectomy/decortication, 126 chemotherapy). Median survival was 12.9 months and the 1-, 2- and 3-year survivals were 51.8%, 21.8% and 12.1%, respectively. Univariate analysis showed no significant difference in survival between the patients diagnosed before or during the pemetrexed era (P = 0.124). The patients receiving pemetrexed or other chemotherapy had median survivals of 16.7 and 15.3 months, respectively. The independent prognostic factors for survival were histology and asbestos exposure. Non-epithelioid histology yielded 17 times higher risk of dying than epithelioid. Asbestos exposure doubled the risk of dying, but only in patients diagnosed in 2003-2006. Conclusions: Pemetrexed is beneficial for selected patients, but it has not changed the outcome of the whole MPM population as much as perhaps anticipated. Patient groups with various treatments or symptomatic care only reached survival results comparable to those reported in chemotherapy trials, thus emphasising the need for better subtyping of mesothelioma and individualising the treatment.