Brain metastases in malignant pleural mesothelioma

The brain is a rare site of metastasis in malignant pleural mesothelioma (MPM), and its clinical features and prognosis remain unclear. The aim of this study was to investigate the incidence, prognosis, and risk factors for brain metastases (BM) in MPM patients. Between July 1993 and October 2014, 150 patients with histologically proven MPM were included in this retrospective study. The cumulative incidence of BM was estimated with the Kaplan-Meier method, and differences between groups were analyzed by the log-rank test. Multivariate logistic regression analysis was applied to assess risk factors for BM. The median follow-up time was 11 months (range 0-154.0 months). A total of eight patients (5.3 %) developed BM during the course of their illness. Multivariate analysis identified age < 65 years (odds ratio [OR] = 5.83, p = 0.038) and International Mesothelioma Interest Group stage IV (OR = 1.69, p = 0.040) as independent factors related to increased risk of developing BM. The 1-and 2-year cumulative rates of BM were 4.0 % (95 % confidence intervals [CI] 1.4-8.5 %) and 5.3 % (95 % CI 2.3-10.2 %), respectively. Our study showed that the overall survival (OS) of patients with BM was worse than that of patients without BM (median OS 6.5 vs. 11.0 months, p = 0.037). The prognosis for BM in MPM patients is poor. Clinicians should perform careful screening for BM, especially in patients with risk factors.