Photosensitizing Medications and Skin Cancer: A Comprehensive Review

SIMPLE SUMMARY: Photosensitizing medications are commonly used in the United States, and studies have begun exploring whether exposure to these medications may be a risk factor for skin cancer. As the population in the United States ages, there are more elderly patients being prescribed photosensitizing medications to treat chronic conditions. At the same time, the incidence of skin cancer is increasing. We summarize current evidence regarding the risk of skin cancer associated with use of each type of photosensitizing medication and highlight gaps in the literature to guide further study. ABSTRACT: (1) The incidence of skin cancer is increasing in the United States (US) despite scientific advances in our understanding of skin cancer risk factors and treatments. In vitro and in vivo studies have provided evidence that suggests that certain photosensitizing medications (PSMs) increase skin cancer risk. This review summarizes current epidemiological evidence on the association between common PSMs and skin cancer. (2) A comprehensive literature search was conducted to identify meta-analyses, observational studies and clinical trials that report on skin cancer events in PSM users. The associated risks of keratinocyte carcinoma (squamous cell carcinoma and basal cell carcinoma) and melanoma are summarized, for each PSM. (3) There are extensive reports on antihypertensives and statins relative to other PSMs, with positive and null findings, respectively. Fewer studies have explored amiodarone, metformin, antimicrobials and vemurafenib. No studies report on the individual skin cancer risks in glyburide, naproxen, piroxicam, chlorpromazine, thioridazine and nalidixic acid users. (4) The research gaps in understanding the relationship between PSMs and skin cancer outlined in this review should be prioritized because the US population is aging. Thus the number of patients prescribed PSMs is likely to continue to rise.