Objective: To revise diagnosis criteria of asbestos-induced occupational lung cancer.
Methods: All literatures which met the criteria of cohort studies with results of lung cancer incidence or mortality among workers exposed to asbestos would incorporate into the systematic review. Meanwhile, the information about diagnosis criteria on asbestos-induced lung cancer in other countries was collected. Meta analysis was used to calculate meta-SMR and its 95% confidence interval.
Results: 21 asbestos-exposed cohorts were summarized. The percentage of all deaths due to mesothelioma was 0 to 36.36%. The main kind of asbestos-exposed raw material was chrysotile which accounted for 47.6%, and 7 cohorts (33.3%) didn't provide the information. There were 13 cohorts in 15 which concluded that the lung cancer risk of workers with asbestos exposure had increased (lung cancer SMR = 1.6 ∼ 6.52, P < 0.05). Meta-SMR of 10 included cohorts is 2.09, with 95%CI 1.73 to 2.52 by using Meta analysis. When cumulative asbestos exposure years were less than one year, the risk of lung cancer had increased (lung cancer SMR = 1.6 ∼ 1.82, P < 0.05). When latent period of lung cancer was more than 15 years, the risk of lung cancer had increased (lung cancer SMR = 2.08 ∼ 3.75, P < 0.05). There were three studies, which had analyzed the relation between cumulative asbestos exposure years and the risk of mesothelioma, showing that when cumulative asbestos exposure years were less than one year, the risk of mesothelioma had increased (mesothelioma SMR = 18.0 ∼ 20.0, P < 0.05). When latent period of mesothelioma was more than 15 years, the risk of mesothelioma had increased.
Conclusion: The emphasis of the new version of asbestos-induced lung cancer and mesothelioma diagnosis criteria should focus on cumulative asbestos exposure years and latent period.