Clinical prognostic factors in pleural mesothelioma: best supportive care and anti-tumor treatments in a real-life setting.

ABSTRACT

BACKGROUND: This study aims to investigate patient- and disease characteristics associated with survival in malignant pleural mesothelioma (MPM) patients with anti-tumor treatment or with best supportive care (BSC). MATERIALS AND METHODS: Consecutive MPM cases diagnosed in North Denmark Region from 1972 to 2015 were reevaluated and verified by two pathologists using modern immunohistochemical techniques. Danish registries and hospital records were used to gather patient-, asbestos exposure-, and disease information. RESULTS: Of the 279 patients, anti-tumor treatment was administered to 184 patients (66.0%). All of those received chemotherapy alone or as part of a multimodal treatment, where pemetrexed was given to 126 (68.5%) patients. Asbestos exposure was documented in 92.5% of all patients. In the treated group, mean age was lower (66 years versus 74 years, p < 0.01), rate of occupational asbestos exposure was higher (74.5 versus 54.7%, p < 0.01), more patients had better performance score (98.4 versus 60%, p < 0.01) and stage was lower (81 versus 63.2%, p < 0.01) compared to the BSC group. Multivariate analysis showed that epithelioid subtype was the only common prognostic factor for OS in both groups. In BSC patients, good PS and female gender was associated with improved OS. Median overall survival (OS) was 17 versus 4 months (p < 0.01), and independently of the histopathological subtype, the median and 2-year survival was higher in the treated versus the BSC group (p < 0.02). CONCLUSIONS: This retrospective study showed that epithelioid subtype is the only independent positive prognostic factor of survival in treated patients with MPM. For BSC patients, the epithelioid subtype, good PS, and female gender were positive prognostic factors, while age and comorbidities were not significant. This study with long-term follow-up of treated and BSC MPM patients can contribute to the clinical stratification of patients. Further validation is appropriate to verify these findings.