JAMA Dermatology.

Shabnam Madani, M.D., from Kaiser Permanente in Walnut Creek, California, and colleagues followed 220,236 patients with AK and 220,236 matched controls to assess the 10-year incidence of cSCC.

The researchers found that the risk for cSCC increased with each year of follow-up by 1.92 percent in patients with AK and by 0.83 percent in matched control patients (hazard ratio, 1.90). However, risk was substantially greater among patients aged 49 years and younger diagnosed with AK (hazard ratio, 6.77). The cumulative incidence of cSCC reached 17.1 percent at 10 years among patients with AK and 5.7 percent in control patients. There was a modest association observed between increased numbers of AKs and increased cSCC risk (≥15 AKs versus one AK: hazard ratio, 1.89). Risk factors for cSCC, other than AK, included older age, White race (a proxy for skin type), history of basal cell carcinoma, and male sex.

"These results can be used to develop recommendations for risk-based patient education, treatment, and surveillance," the authors write.

Abstract/Full Text (subscription or payment may be required)