Basal Cell Carcinoma Chemoprevention Trial

Inclusion Criteria: * Veteran age 18 years or older * 2 (or more) qualifying BCC lesions in the prior 5 years, with at least one located on the face, neck, ears, or scalp. "Qualifying lesions are those that meet the two inclusion criterion bullet points below, and none of the exclusion criteria listed in "B". * Qualifying lesions not in a field of prior radiation therapy. * Qualifying lesions not a recurrence after treatment, but the original lesion can qualify whether it recurred or not. Exclusion Criteria: * AK or KC field therapy on the face (5-FU cream, IMQ, diclofenac gel, chemical peel, or photodynamic therapy) for BCC treatment on the face in the last 2 months because it can cause inflammation that may interfere with the IMQ treatment. After 2 months, these patients can be included. * IMQ therapy on the face in the past year, although such therapy in the more distant past is not an exclusion. * Suspicious skin lesions suggestive of any type of skin cancer present on the face at the initial exam conducted for the study must be removed and have another skin exam to confirm the facial skin cancer is cleared for 1 month prior to randomization so that the investigators can be confident that skin cancer lesions that arise during the trial are new. * Currently receiving or received in the past two months: immune checkpoint inhibitor, hedgehog pathway inhibitor, or oral capecitabine. * History of cutaneous T-cell lymphoma within the past year, but low-grade prostate cancer,…