Relationship between arsenic intake and internal malignant neoplasms

An attempt has been made to assess the carcinogenic effect of arsenic intake by analyzing a group of patients who were treated with arsenic for various skin diseases in the 1930s. When compared with the expected incidence of malignant internal neoplasms, based on figures obtained from the Danish Cancer Registry, a significant increase in the incidence of internal malignant neoplasms was observed in females with multiple basal cell carcinomas. A group comprising 53 patients with arsenic keratoses presented a considerable increase in the incidence of internal malignant neoplasms. However, these patients were so specifically selected that no regular statistical analysis can be made of this group. It may be said that arsenic has a carcinogenic effect even in the relatively small doses applied in dermatological therapy.