Incidence of malignant pleural mesothelioma due to environmental asbestos fiber exposure in the southeast of Turkey.

BACKGROUND: Inhabitants of the southeast of Turkey (ST) have been exposed since childhood to inhalation of asbestos, from a material containing tremolite, used for whitewashing. This has resulted in an increased incidence of malignant pleural mesothelioma (MPM). OBJECTIVES: To review the epidemiological features of MPM cases in ST; to calculate and compare the incidence with the previously reported ones. SUBJECTS AND METHODS: The study included 176 MPM cases from different places in ST. The incidence of MPM was calculated for those places according to the distribution of the cases. RESULTS: In the previously identified regions of asbestos (region 1) where the population had been informed of the danger with the soil some decades ago, the MPM incidence was decreased, as compared to the previous reports. The annual incidence of MPM in these places was found to be 42.9 per million in this study while it had been reported to be 105.5 per million in the previous studies. In contrast, the incidence that was reported previously to be 2.75 per million in the regions where asbestos exposure had not been identified before (region 2) was found to be 8.6 per million in this study. In region 2 the incidence of MPM increased even in the second half of the last decade (5.9 versus 11.9 per million). CONCLUSIONS: Use of asbestos-containing soil continues in different places in ST. Even if the use of this soil is abandoned today, MPM will be an important health problem in this region till the third or fourth decades of this century. Informing the villagers of the danger and preventing the use of this soil may result in a considerable decrease in the incidence of MPM.

Malignant pleural mesothelioma caused by environmental exposure to asbestos in the Southeast of Turkey: CT findings in 117 patients.

BACKGROUND AND OBJECTIVES: Malignant pleural mesothelioma (MPM) is reported to be common in the southeast of Turkey, as a result of environmental asbestos exposure. The aim of this study was to evaluate the computed tomography (CT) features of MPM in patients with a history of asbestos exposure. METHODS: The CT scans of 117 patients who had a diagnosis of MPM were retrospectively evaluated. Additionally, CT findings of histologic subtypes were compared. RESULTS: The most common CT findings included pleural effusion (n = 104, 89%), pleural thickening (n = 96, 82%), mediastinal pleural involvement (n = 77, 66%) and interlobar fissural involvement (n = 62, 53%). Histologic subtype analysis was performed in 89 patients; of these, epithelial, sarcomatous and mixed types were identified in 46, 23 and 20 patients, respectively. An analysis of CT findings demonstrated that the involvement of mediastinal pleural (91%), interlobar fissure (87%) and lung parenchyma (48%) was significantly more frequent in sarcomatous type, as compared to epithelial (61% and p < 0.01; 35 and 4%, p < 0.0001, respectively) and mixed types (65% and p < 0.05; 10% and p < 0.0001; 10% and p < 0.01, respectively). Furthermore, there was a significant correlation between pericardial involvement and chest wall involvement (r = 0.42, p < 0.05) in sarcomatous type. Similarly, lymphadenopathy and parenchymal involvement (r = 0.23, p < 0.02), pericardial and chest wall involvement (r = 0.25, p < 0.01), chest wall and interlobar fissural involvement (r = 0.25, p < 0.01) were significantly correlated, when CT findings of all histologic subtypes were combined. CONCLUSIONS: These results suggest that although CT findings of MPM vary, they may provide valuable clues to the diagnosis, at least in patients with a history of asbestos exposure. In addition, the presence of extensive lesions may suggest MPM of sarcomatous subtype.

Comparison of the effectiveness of some pleural sclerosing agents used for control of effusions in malignant pleural mesothelioma: a review of 117 cases.

BACKGROUND AND OBJECTIVES: Management of malignant pleural mesothelioma (MPM) has been an important clinical issue regardless of the treatment modality employed. We aimed to investigate the efficacy of oxytetracycline (OT), Corynebacterium parvum (CP), and nitrogen mustard (NM) in the management of pleural effusion associated with MPM. METHODS: One hundred and seventeen patients who had stage-2 MPM or over according to the Butchart staging system and unilateral or bilateral pleural effusion took part in the study. The patients received either OT (35 mg/kg), CP (7 mg), or NM (0.4 mg/kg) through a chest tube for pleurodesis. The association between several clinical parameters and patient survival was also investigated. RESULTS: OT was applied to 59, CP to 29 and NM to 29 cases. A statistical analysis of the results obtained by these agents have demonstrated that OT (30 days, 81%; 90 days, 76.2%) and CP (30 days, 86.2%; 90 days, 79.3%) led to a significantly higher rate of successful pleurodesis as compared to NM (30 days, 48.2%; 90 days, 41.3%; p <0.05). Although the procedure was generally well tolerated by the patients, the NM-treated group experienced significantly more nausea-vomiting (46.1%) and hypotension (35.8%) compared to patients who received OT (nausea-vomiting and hypotension 4.3%; p < 0.001) and CP (nausea-vomiting and hypotension 5.1%; p < 0.001). Furthermore, we found that thrombocytosis, chest pain and weight loss were significantly associated with poor prognosis, whereas epithelial type had a positive effect on survival. CONCLUSION: These results suggest that OT and CP may be used as effective sclerosing agents for pleurodesis in the control of pleural effusions associated with MPM, without major side effects.