Our data suggest that the VEGF serum concentration could be a useful marker for screening MPM among asbestos-exposed individuals and as a prognostic factor.

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor of mesothelial origin associated with asbestos exposure. MPM has a limited response to conventional chemotherapy and radiotherapy, thus early diagnosis of MPM is extremely critical. CT scans have limited accuracy in the differentiation between benign and malignant pleural disease. Several studies have reported that 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) plays an important role in the assessment of thoracic malignancy such as lung cancer. Here, we investigated the clinical utility of PET in patients with MPM. The maximum SUV (SUVmax) of 18F-FDG was measured in 47 MPM patients and 29 non-MPM patients including those with pleural thickening. We demonstrated that patients with MPM had significantly higher SUVmax levels than a population with non-malignant pleural disease. The Kaplan-Meier method revealed significant differences in overall survival between groups with SUVmax levels lower and higher than the assumed cut-off. Our data suggest that SUVmax levels are useful as an aid for diagnosis and prognosis of MPM.

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumour of mesothelial origin associated with asbestos exposure. Because MPM has limited response to conventional chemotherapy and radiotherapy, the prognosis is very poor. Several researchers have reported that cytokines such as interleukin (IL)-6 play an important role in the growth of MPM. Previously, it was reported that all-trans-retinoic acid (ATRA) inhibited the production and function of IL-6 and transforming growth factor (TGF)-b1 in experiments using lung fibroblasts.We investigated whether ATRA had an inhibitory effect on the cell growth of MPM, the origin of which was mesenchymal cells similar to lung fibroblasts, using a subcutaneous xenograft mouse model. We estimated the tumour growth and performed quantitative measurements of IL-6, TGFb1 and platelet-derived growth factor (PDGF) receptor (PDGFR)-b mRNA levels both of cultured MPM cells and cells grown in mice with or without the administration of ATRA.ATRA significantly inhibited MPM tumour growth. In vitro studies disclosed that the administration of ATRA reduced 1) mRNA levels of TGF-b1, TGF-b1 receptors and PDGFR-b, and 2) TGF-b1-dependent proliferation and PDGF-BB-dependent migration of MPM cells.These data may provide a rationale to explore the clinical use of ATRA for the treatment of MPM.

The findings of this study suggest that long (GT)n repeats in the HO-1 gene promoter are associated with a higher risk of malignant mesothelioma in the Japanese population.

Objective: Existing prognostic indices for malignant pleural mesothelioma do not incorporate the recent advances in oncology care. The purpose of this study was to provide a prognostic index for overall survival in malignant pleural mesothelioma patients treated with chemotherapy with pemetrexed or best supportive care in the recent clinical setting. Methods: A retrospective cohort study was performed in two hospitals in Japan . The primary outcome was overall survival. The Cox proportional hazards model was used for multivariable analyses to identify prognostic factors. A final model was chosen based on both clinical and statistical significance. Results: A total of 283 patients (chemotherapy: n = 228, best supportive care: n = 55) were enrolled in the study. On multivariate analysis, regimen including platinum plus pemetrexed, a performance status >0, non-epithelial histological type and Stage IV disease predicted poor overall survival in chemotherapy patients. As hazard ratios of individual risk factors were approximately similar, a prognostic index for overall survival was constructed by counting the risk factors. Median overall survival in chemotherapy patients decreased by each one-point increase in this count: 1030 days for zero; 658 days for one; 373 days for two; 327 days for three; 125 days for four. Internal validation using the bootstrapping technique showed robustness of the model (c-index, 0.677; 95% confidence interval, 0.624-0.729). Further, the discrimination was consistent in best supportive care patients (c-index, 0.799; 95% confidence interval, 0.725-0.874). Conclusions: This novel index can provide clinicians and malignant pleural mesothelioma patients with a better framework for discussing prognosis at the time of diagnosis.