Sun Damage May Increase Skin Cancer Risk For 10 Years

Actinic keratosis (AK) may increase the risk of later development of cutaneous squamous cell carcinoma (cSCC) in adults, according to the results of a recent study.

To examine the relationship between a diagnosis of AK and the incidence of cSCC over a 10-year follow-up period, the researchers conducted a longitudinal cohort study. Included were 220,236 participants with AK and 220,236 matched control participants. The study ran from January 2009 to February 2020 and utilized the Kaiser Permanente Northern California health care system.

The results indicated that with each year of follow-up, the risk of cSCC increased by 1.92% in patients with AK (95% CI, 1.89%-1.95%), compared with a 0.83% increase in the control patients (95% CI, 0.81%-0.85%). At the completion of the 10-year follow-up period, the cumulative incidence of cSCC was 17.1% in patients with AK (95% CI, 16.9%-17.4%), compared with 5.7% in control patients (95% CI, 5.5%-5.9%). Additionally, the results indicated that increased numbers of AKs were modestly associated with increased cSCC risk.

Patients who were diagnosed with AK at age 49 years or younger were nearly 7 times more likely to be later diagnosed with cSCC (HR, 6.77; 95% CI, 5.50-8.32) than those never diagnosed with AK, and older patients (≥80 years of age) had a much higher risk of cSCC than younger patients (HR, 8.18; 95% CI, 7.62-8.78).

In their study the researchers also identified risk factors for the development of cSCC. In addition to an AK diagnosis and older age, White race, history of basal cell carcinoma, and male sex were among the risk factors identified.

“The results of this longitudinal cohort study can be used to develop recommendations to increase early detection of cSCC. Additional research is needed to understand the effect of AK treatment on cSCC risk and outcomes of cSCC,” the researchers concluded.

—Leigh Precopio

Reference:

Madani S, Marwaha S, Dusendan JR, et al. Ten-year follow-up of persons with sun-damaged skin associated with subsequent development of cutaneous squamous cell carcinoma. JAMA Dermatol. Published online March 24, 2021. doi: /10.1001/jamadermatol.2021.0372