7. Gorlin syndrome or other genetic skin cancer syndrome
8. Solid organ or hematologic malignancy, invasive Stage II melanoma, Merkel cell carcinoma, or metastatic skin cancer within the past five years, or invasive Stage I melanoma within the past two years
9. Untreated localized skin cancer (invasive squamous cell carcinoma, basal cell carcinoma, or keratoacanthoma) at baseline (the patient can enrol after skin cancer treatment)
10. Use of nicotinamide or niacin (250 mg or more daily) within the past 12 weeks
11. Use of field therapy for actinic keratoses within the past 12 weeks
12. Initiation of systemic chemoprevention within the past 12 weeks
Clareo Health | Skin Cancer Prevention With Nicotinamide in Transplant Recipients - Pilot Trial
