From the aDepartment of Occupational and Environmental Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan; bDepartment of Occupational and Environmental Medicine, National Cheng Kung University Hospital, Tainan, Taiwan; cDepartment of Pathology, Kaohsiung Municipal United Hospital, Kaohsiung, Taiwan; dDepartment of Environmental and Occupational Health, College of Medicine, Tainan, Taiwan; and eOccupational Safety, Health, and Medicine Research Center, National Cheng Kung University, Tainan, Taiwan.
Epidemiology. 2017 Oct;28 Suppl 1:S106-S112. doi: 10.1097/EDE.0000000000000743.
Arsenic is a well-documented human carcinogen, and studies on urinary and skin cancers have shown that the carcinogenicity of ingested arsenic has cell-type specificity. To evaluate whether this is also true for lung cancers, we conducted a study on 243 townships in Taiwan.
The arsenic levels were assessed using measurement reports from a previous survey, and the incidence of lung cancer was assessed using the data gathered by the National Cancer Registry Program. We analyzed data by regression models with multiple variables to describe exposure levels; each variable denoted the proportion of people in a specific exposure category in each township. An urbanization index and variables denoting the distribution of age in each township were also included in the model to adjust for effects of urbanization and age.
Among the three major cell types of lung cancer, squamous cell carcinoma appeared to be associated with arsenic level in drinking water, and the association was more prominent at exposure level above 0.64 mg/L in both men and women. A 1% increase in the proportion of wells in this category was associated with an increase of 0.27 per 100,000 per year in the incidence of squamous cell lung cancer in men and 0.13 per 100,000 per year in women. Adenocarcinoma and small cell carcinoma were not associated with arsenic level in drinking water.
The results suggested that the carcinogenicity of arsenic on lungs is cell-type specific, which is compatible with observations on urinary and skin cancers. Whereas data in the literature were limited, the association between adenocarcinoma and arsenic exposures through inhalation appeared to be stronger than that of squamous cell carcinoma. Therefore, different exposure routes may give rise to different mechanisms in the carcinogenicity of arsenic.
砷是一种有充分文献记录的人类致癌物，有关尿路上皮癌和皮肤癌的研究表明，摄入砷的致癌性具有细胞类型特异性。为了评估这是否也适用于肺癌，我们在台湾的 243 个乡镇进行了一项研究。
使用先前调查的测量报告评估砷含量，使用国家癌症登记计划收集的资料评估肺癌发病率。我们通过回归模型分析多变量数据，以描述暴露水平；每个变量表示每个乡镇特定暴露类别的人群比例。模型中还包括城市化指数和表示每个乡镇年龄分布的变量，以调整城市化和年龄的影响。
在肺癌的三种主要细胞类型中，鳞状细胞癌似乎与饮用水中的砷含量有关，而且在男性和女性中，暴露水平高于 0.64mg/L 时，这种关联更为明显。该类别中井的比例增加 1%，与男性鳞状细胞肺癌发病率每年每 100,000 人增加 0.27 例和女性每年每 100,000 人增加 0.13 例相关。腺癌和小细胞癌与饮用水中的砷含量无关。
结果表明，砷对肺部的致癌性具有细胞类型特异性，这与对尿路上皮癌和皮肤癌的观察结果一致。虽然文献中的数据有限，但通过吸入途径暴露于腺癌和砷之间的关联似乎比鳞状细胞癌更强。因此，不同的暴露途径可能导致砷致癌性的不同机制。
