High Rates of Actinic Keratosis Lesion Recurrence, Even After Clearance

Actinic keratosis
Actinic keratosis – a precursor to squamous cell carcinoma or skin cancer on a man’s hand
The long-term recurrence rates of actinic keratosis lesions from a number of studies is examined.

Studies suggest treatment of actinic keratosis (AK) can lead to short-term lesion clearance within 3 to 6 months, but few studies to date have examined the long-term recurrence rate of these lesions. Study findings published in the Journal of the American Academy of Dermatology show long-term recurrence of AK lesions is relatively high, even among patients who have achieved lesion clearance with active treatment.

The study was a systematic review of AK recurrence rates reported in 9 parallel-arm randomized controlled trials. Specifically, the investigators assessed participant- and lesion-specific recurrence rates reported 12 months or longer following AK treatment completion.

Treatments associated with the lowest recurrence rate (39%) were cryotherapy (95% CI, 20-62%) and photodynamic therapy with 5-aminolevulinate (ALA-PDT) (95% CI, 33-45%). These were followed by placebo (44%; 95% CI, 25-65%), PDT with methyl-aminolevulinate (MAL-PDT) (45%; 95%, 38-51%), and imiquimod (45%; 95% CI, 14-81%).

Higher participant-specific recurrence rates were reported in studies investigating treatment with diclofenac (85%; 95% CI, 70-94%). This was followed by treatment with ablative laser (54%; 95% CI, 18-86%) and 5-fluorouracil (52%; 95% CI, 38-66%). In 4 randomized controlled trials, lesion-specific recurrence rates were lower for placebo (15%; 95% CI, 10-22%), followed by ALA-PDT (20%; 95% CI 16-24%) and then MAL-PDT (34%; 95% CI 23-47%).

Limitations of this study were its retrospective nature as well as the relatively small number of studies included in the analysis.

The investigators conclude their findings “challenge the value of short-term clearance rates which are usually reported and serve as primary endpoints in” studies “and highlight the nature of AK as a chronic health condition.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Steeb T, Wessely A, Petzold A, et al. Long-term recurrence rates of actinic keratosis: a systematic review and pooled analysis of randomized controlled trials. J Am Acad Dermatol. Published online April 16, 2021]. doi:10.1016/j.jaad.2021.04.017