A new prognostic index for overall survival in malignant pleural mesothelioma: the rPHS (regimen, PS, histology or stage) index.

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 (2007-13). 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.

Clinical significance of serum angiopoietin-1 in malignant peritoneal mesothelioma.

We have previously reported that angiopoietin-1 was correlated with pulmonary fibrosis. Here, we investigated the serum levels of angiopoietin-1 in patients with malignant peritoneal mesothelioma, which originate from mesenchymal cells similar to lung fibroblasts. We showed that patients with peritoneal mesothelioma had significantly higher serum levels of angiopoietin-1 in comparison with a population with a history of asbestos exposure without peritoneal mesothelioma, and the Kaplan-Meier method revealed a significant correlation between serum angiopoietin-1 levels and survival. This is the first report about the relationship between angiopoietin-1 and peritoneal mesothelioma.

Serum thioredoxin-1 as a diagnostic marker for malignant peritoneal mesothelioma.

BACKGROUND: Diffuse malignant peritoneal mesothelioma (DMPM) is an aggressive malignant tumor of mesothelial origin that shows a limited response to cytoreductive surgery along with intraperitoneal chemotherapy. Therefore, diagnosing DMPM early is very important. Reactive oxygen species play an important role in asbestos toxicity, which is associated with the pathogenesis of DMPM growth. Thioredoxin-1 (TRX) is a small redox-active protein that demonstrates antioxidative activity associated with tumor growth. Here, we investigated the serum levels of TRX in patients with DMPM and compared them with those of a population that had been exposed to asbestos but did not have DMPM. STUDY: The serum concentrations of TRX were measured in 15 DMPM patients and 34 individuals with benign asbestos-related diseases. RESULTS: We demonstrated that the patients with DMPM had significantly higher serum levels of TRX than the population that had been exposed to asbestos but did not have DMPM. CONCLUSIONS: Our data suggest that serum TRX concentration is a useful serum marker for DMPM.

Heme oxygenase-1 promoter polymorphism is associated with risk of malignant mesothelioma.

BACKGROUND: Malignant mesothelioma is an aggressive tumor of serosal surfaces that is closely associated with asbestos exposure which induces oxidative stress. Heme oxygenase (HO)-1, a rate-limiting enzyme of heme degradation, plays a protective role against oxidative stress. The HO-1 gene promoter carries (GT)n repeats whose number is inversely related to transcriptional activity of the HO-1 gene. METHODS: To investigate the relationship between the length polymorphism of (GT)n repeats and mesothelioma susceptibility, we analyzed the HO-1 promoter in 44 asbestos-exposed subjects without mesothelioma and 78 asbestos-exposed subjects with mesothelioma using PCR-based genotyping. RESULTS: The number of repeats ranged from 16 to 38, with two peaks at 23 and 30 repeats. Polymorphisms of (GT)n repeats were grouped into two classes of alleles, short (S) (<24) and long (L) (≥24), and three genotypes: L/L, L/S, and S/S. The proportions of allele frequencies in class L as well as genotypic frequencies of L allele carriers (L/L and L/S) were significantly higher in the asbestos-exposed subjects with mesothelioma than in those without mesothelioma. CONCLUSION: 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.

Bevacizumab helped resolve pericardial and pleural effusion that was associated with malignant ovarian clear cell carcinoma.

•An ovarian clear cell carcinoma patient showed malignant pericardial and pleural effusion.•She subsequently experienced pulmonary embolism due to cancer progression.•Pericardial and pleural effusion were successfully treated using bevacizumab.

Methotrexate and gemcitabine combination chemotherapy for the treatment of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive tumor of serosal surfaces with a poor prognosis. Methotrexate and gemcitabine have exhibited single-agent activity in MPM. We evaluated the feasibility of sequential administration of these agents in the treatment of MPM. A total of 21 patients with MPM received a 30-min infusion of 100 mg/m2 methotrexate and, 30 min later, a 30-min infusion of 800 mg/m2 gemcitabine. Twenty-four hours following the administration of methotrexate, leucovorin rescue therapy was initiated (10 mg/m2 leucovorin administered 4 times at 6-h intervals). These treatments were administered weekly, with 4 weekly administrations constituting a cycle of therapy. A total of 88 cycles were administered to the 21 patients, with each patient receiving 1-10 cycles (median, 4.2 cycles). Eight patients (38.1%) exhibited a partial response, 10 patients (47.6%) had stable disease and 3 patients (14.3%) had progressive disease. The median overall survival was 19.4 months (range, 02-41 months). One-year and 2-year survival rates were 61.9 and 38.1%, respectively. Hematological toxicity was considered acceptable, with grade 3-4 toxicities occurring in 3 (14.3%) patients. Non-hematologic toxicity was generally mild. There was no treatment-related mortality. Our results suggest that methotrexate and gemcitabine combination therapy is feasible and effective in the treatment of MPM. This regimen may offer an alternative to platinum-based chemotherapy and a prospective trial including a larger cohort of patients is recommended to confirm these results.

Clinical utility of 18-fluorodeoxyglucose positron emission tomography/computed tomography in malignant pleural mesothelioma.

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.

Clinical significance of serum vascular endothelial growth factor in malignant pleural mesothelioma.

INTRODUCTION: 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 so diagnosing MPM early is very important. Vascular endothelial growth factor (VEGF) is an autocrine growth factor for MPM. Here, we investigated the serum levels of VEGF in patients with MPM in comparison with a population that had been exposed to asbestos without developing MPM. METHODS: Serum concentrations of VEGF were measured in 51 patients with MPM and 42 individuals with benign asbestos-related diseases (asbestosis or pleural plaques) or who were healthy despite asbestos exposure. RESULTS: We demonstrated that patients with MPM had significantly higher serum levels of VEGF than a population who had been exposed to asbestos but had not developed MPM, and the patients with advanced stage MPM showed higher levels of VEGF than the early stage patients with MPM. The difference in overall survival between the groups with VEGF serum levels lower and higher than the assumed cutoff of 460 pg/ml was significant. CONCLUSIONS: 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.

Well-differentiated papillary mesothelioma with invasion to the chest wall.

Well-differentiated papillary mesothelioma (WDPM) is an uncommon tumor with a papillary architecture, bland cytologic features, a tendency toward superficial spread without invasion, and good prognosis with prolonged survival. WDPM occurs primarily in the peritoneum of women, but also rarely in the pleura. We here report a case of 48-year-old woman who developed WDPM in the pleura with no history of asbestos exposure. Tumors were multifocal and widespread with a velvety appearance on the surface of parietal and visceral pleurae resected by extrapleural pneumonectomy (EPP). Tumors showed papillary structures with fibrovascular cores and lined by epithelioid cells. Immunohistochemically, these epithelioid tumor cells were positive for epithelial membrane antigen (EMA), a marker of malignant mesothelioma, with more than 50% positive for p53. Tumor cells microinvaded into subpleural parenchyma of the lung and minimally spread to adipose tissues of the mediastinal lesion. In addition, tumor cells invaded into the chest wall with a trabecular or glandular architecture. Based on these findings, this case is pathologically considered as WDPM of the pleura with malignant potential.