OBJECTIVETo explore the risk factors for mesothelioma so as to provide epidemiological evidences for prevention of this disease and for further study of its pathogenesis.

METHODSA 1:1 paired case-control study was carried out in which asbestos exposure, life style and histories of cancer in first-degree relatives of 23 patients who had mesothelioma were compared with those of controls.

RESULTSThe mean age of patients was 57.96 years with a latency period of 52 years. There were no significant differences in mean exposure age, mean exposure periods, and smoking, drinking habits between patients and controls. The mean cumulative exposure of patients was 37.2 x 10(5) f, which was significantly higher than that of controls (32.3 x 10(5) f, P = 0.005). The odds ratio increased with the cumulative exposure. The percentage of cancer in first-degree relative of patients (26.1%) was significantly higher than that of controls [(4.4%, P < 0.05), OR = 7.75 (95% CI: 0.85-71.43)].

CONCLUSIONThere may be a dose-response relationship between mesothelioma and asbestos exposure. A family history of cancer may be a risk factor for mesothelioma, or may indicate an increased susceptibility to mesothelioma under the same level of asbestos exposure.