Intralesional chemotherapy for nonmelanoma skin cancer: a practical review.

Intralesional chemotherapy for nonmelanoma skin cancer has existed for more than 5 decades. However, it is used so infrequently that recent consensus guidelines for the treatment of basal cell and squamous cell carcinoma do not include intralesional chemotherapy. Barriers to the use of intralesional chemotherapy include the off-label use of these agents, absence of therapeutic guidelines, a relatively small number of patients treated, and a lack of large, well-designed trials with long-term follow-up. Surgical intervention remains the gold standard for the treatment of nonmelanoma skin cancer; however, intralesional chemotherapy remains an option for well-selected patients who cannot or will not undergo surgery. The objectives of this article are to determine response rates and suggest reasonable treatment guidelines for the treatment of squamous cell carcinoma, keratoacanthoma, and basal cell carcinoma with the most widely available intralesional agents (methotrexate, 5-fluorouracil, bleomycin, and interferon).