石棉接触人员消化系统癌症死亡队列研究的Meta分析

目的 以Meta分析探讨石棉接触者消化系统癌症是否高发.方法 凡满足明确是石棉接触人员且为消化系统癌症死亡率队列研究的资料均被纳入研究对象,以直接法与随机效应模型法计算消化系统主要部位癌症标准化死亡比(SMR)及其95%可信区间(CI),计算Q统计量与Z值检验研究结果异质性及其来源.结果 共有69个队列符合入选标准,单纯接触温石棉、温石棉与闪石类石棉混合作业的人员,全死因、全癌亡、消化系统癌症和胃癌的meta-SMR明显上升,SMR分别为1.16、1.42、1.15、1.20,差异均有统计学意义(P<0.01).胃癌meta-SMR明显升高,主要见于石棉水泥工、采选矿工与绝缘工SMR分别为1.27,1.21与2.13,差异均有统计学意义(P<0.05).敏感性分析提示,Meta分析结果是稳健的.食管、结肠、直肠、肝等其他消化系统部位癌症的meta-SMR未见明显上升.结论 石棉暴露似能使作业人员胃癌明显高发,与其他消化系统部位癌症无病因联系.

Cohort studies on cancer mortality of digestive system among workers exposed to asbestos:a meta-analysis

Objective To determine if there are excessive risks of malignant tumors or not among workers exposed to asbestos by applying a meta-analysis technique. Methods All clata meeting the criteria of cohort studies on cancer mortality of digestive system among workers exposed to asbestos would be incorporated into the meta-analysis. The pooled standardized mortality ratios (SMR) and their corresponding 95% confidence intervals (CIs) for main cancer sites of digestive system were calculated by using two approaches of unweighted ratio and random effects model. The heterogeneity and its sources of the results were examined with a Q-statistic and Z-score test. Results 69 asbestos-exposed cohorts were summarized. The significantly elevated meta-SMR for all deaths (1.16),all cancers (1.42),cancer of digestive system (1.15) and cancer of stomach (1.20) among workers exposed to chrysotile alone or mixed asbestos were observed (P<0.01). The stomach cancer SMR was significantly increased in the asbestos cement workers,the screening mine workes and the insulators, (1.27,1.21 and 2.13 respectively) (P<0.05). meta-SMR for cancers at other sites of digestive system induding esophagus, colon, rectum and liver were not significant. Conclusion There are likely excessive risks of cancer of stomach among workers exposed to asbestos. However, there is likely no convincing indication of an etiological association between asbestos exposure and cancers at other sites of digestive system.