Arsenic exposure in a copper smelter as related to histological type of lung cancer

Tissue samples from lung cancer patients who had worked at a copper smelter and from controls were collected and classified by a panel of pathologists: 38% of the cancers were found to be adenocarcinomas, compared to 12% among the controls, a statistically significant difference (p less than 0.05). The predominance of adenocarcinomas was associated with arsenic exposure. This finding is not consistent with Kreyberg's hypothesis that small-cell undifferentiated and epidermoid carcinomas are the only type that increase in response to inhaled carcinogens [1962].