The occurrence of the interstitial lung disease (ILD) during anti-cancer drug therapy is uniquely high in Japanese patients with lung cancer. Patients with malignant mesothelioma, of which the number is increasing in Japan, may be also at risk of ILD. In this study, we examined ILD among patients of malignant mesothelioma in the western part of Japan from 1998 to 2007.
 Patients with malignant mesothelioma diagnosed during 1998 to 2007 in the western part of Japan were examined by the questionnaire method. Age, gender, site, histology of mesothelioma, survival, therapy (including drugs) and complication of ILD were examined. Four specialists made final diagnosis by the radiological and pathological information.
 Three hundred and eighty four patients were registered. However, 28 patients were finally not diagnosed, 28 patients were not confirmed and therefore the remaining 328 patients were finally diagnosed as mesothelioma. Two hundred and eighty five (87% of 328) were male and median age was 66 years old. Three hundred and fourteen patients of mesothelioma originated from pleura, 12 from peritoneum, 1 from pericardium and 1 from tunica vaginalis. Median survival was 10 months.
 Twenty one patients developed ILD. All were male and median age was 66 years old. Six patients got the exacerbation of chronic ILD and other 15 patients had new lesion of ILD. As to the type of ILD patterns in chest CT scanning, 21 patients consisted of 9 with simple ground glass opacity, 5 with nonspecific interstitial pneumonia(NSIP), 4 with acute interstitial pneumonia(AIP), 2 with cryptogenic organized pneumonia(COP) and 1 with diffuse alveolar damage(DAD). Three patients had no potential causative factors, but for other 18 patients had one or more potential causes. Fifteen cases were potentially induced by drugs; 7 patients, (9.5% of 74 patients at risk) by the combination of gemcitabine(GEM) and vinorelbine(VNR), 4 patients(6.0% of 67 patients at risk), by OK-432 with pleurodesis and each of the remaining 4 patients by GEM, VNR, CBDCA+irinotecan, and paclitaxel, respectively. Other causes included extrapleural pneumonectomy, radiation and infection.
 Twenty one patients (6.4%) from 328 malignant mesothelioma had ILD during the clinical course. Fifteen of 21 cases were induced by anti-cancer drugs. We should take care of ILD developing during the therapy of malignant mesothelioma, especially when using anti-cancer drugs.

99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA