200 Risks and timing of future skin cancers in patients with actinic keratosis

Abstract

Actinic keratoses (AKs) are commonly diagnosed during dermatology visits and used to guide follow up care, such as skin cancer screening exams. However, prior research on AKs has focused on individual lesions: their rates of regression, recurrence, and progression to skin cancer. On a patient level rather than a lesion level, the risks and timing of skin cancers after a patient has had an AK have not been well studied, however. To evaluate this, we performed a cohort study using the OptumInsights Electronic Health Record Database between July 1, 2007 and June 30, 2017 among patients with AKs. We included 14,490 patients with at least one year of dermatology follow-up prior to their first AK in the cohort and no known history of basal cell carcinoma (BCC), squamous cell carcinoma (SCC), or melanoma. Mean follow-up was 2.0 years (SD 1.8 years). Using survival analysis, we calculated that the risk of a subsequent AK after an initial AK was 42% (95% CI 41%-43%) at 1 year and 65% (95% CI 65%-66%) at 2 years. The risk of either BCC or SCC after an initial AK was 8% (95% CI 8%-9%) at 1 year and 14% (95% CI 14%-15%) at 2 years. When we divided BCC and SCC outcomes, the risks of subsequent BCC and of subsequent SCC were similar. The risk of melanoma was 0.8% (95% CI 0.6%-1%) at 1 year and 1.6% (95% CI 1.4%-1.9%) at 2 years. Our findings suggest that patients with AK are highly likely to develop another AK and have sizeable and similar risks of both BCC and SCC, with more than one in ten patients developing BCC or SCC in the first two years after an AK. Risks of melanoma, while smaller, are still considerable. These results provide evidence of AKs as biomarkers of skin cancer risk overall, beyond the risk of an individual AK lesion transforming into a carcinoma.