The objective of this study was to assess the risk of invasive cancers following a diagnosis of basal cell carcinoma (BCC) of the skin. For this purpose, a cohort study of all patients with incident BCC listed in the cancer registries of the Swiss cantons of Vaud and Neuchatel was conducted between 1974 and 1994. Patients were actively reexamined through December 1994, and the occurrence of subsequent invasive neoplasms was ascertained. No generalized excess of nonskin cancers following BCC was found; however, an excess of other skin cancers was found that was large enough to justify the recommendation that careful surveillance of skin lesions be carried out in patients with BCC.
Masini C. What Is the Risk of a Second Invasive Cancer Following Basal Cell Skin Carcinoma?. Arch Dermatol. 1999;135(12):1531-1532. doi:10.1001/archderm.135.12.1531