In a study of the value of long-term follow-up after treatment of basal cell carcinoma, new skin cancers were found in 20% of patients examined during a one-year period. The majority of these new skin cancers were unsuspected by the patient. The risk of developing a new skin cancer was directly related to the number of previous basal cell carcinomas. While 20% of the entire group developed new skin cancers, 41% of those who had two or more previous skin cancers developed a new lesion, and of those having had three or more previous carcinomas, 56% developed skin cancers. The author believes that long-term follow-up for skin cancer patients is indicated to detect new tumors, and urges that all patients having had two or more previous basal cell carcinomas be followed up indefinitely.
Epstein E. Value of Follow-Up After Treatment of Basal Cell Carcinoma. Arch Dermatol. 1973;108(6):798-800. doi:10.1001/archderm.1973.01620270024004