Predictors for successful actinic keratosis treatment

Strong predictors for achieving a favorable actinic keratosis treatment response from ingenol mebutate 0.015% gel are dermoscopic detection of red pseudonetwork lesions and facial location, according to a new study.

“[Ingenol mebutate 0.015%] is an attractive nonsurgical treatment for [actinic keratosis] that has been established in pivotal studies and conformed in phase 3 trials,” the authors write.

But the definition of which lesions might benefit from treatment with ingenol mebutate 0.015% gel--an approved field treatment for non-hyperkeratotic non-hypertrophic actinic keratoses of the face and scalp--is purely descriptive, according to the authors.

To help dermatologists and others to choose the best treatment option for their actinic keratosis patients, researchers looked at whether dermoscopic criteria can help predict actinic keratosis response.

They retrospectively studied 55 patients who had been clinically and dermoscopically diagnosed for non-hypertropic, non-hyperkeratotic actinic keratoses and treated with ingenol mebutate 0.015% gel for three consecutive days. There were 245 actinic keratoses on the face and scalp in the study population. Researchers defined clinical and dermoscopic responses as complete; partial, with 75 percent or more clearance and; poor with less than 75 percent clearance. They assessed patients for dermoscopic features, including pseudonetwork, strawberry pattern, red starburst pattern, scales, micro-erosions rosettes and crystalline structures.

The large number of lesion in the study represents the general actinic keratosis population, according to the authors.

Researchers found that while lesions on the face were more likely to respond to the treatment than those on the scalp, actinic keratoses on the scalp also responded well to ingenol mebutate 0.015% gel. Actinic keratoses on the face and those characterized dermoscopically to be red pseudonetwork, which lack structure and look like red areas intermingled with small roundish white areas, were nearly two times more likely to achieve complete dermoscopic clearance.

On the other hand, actinic keratoses with micro-erosions at the study’s start were 54 percent less likely to achieve complete response during the study.

They found 54.5 percent of patients achieved overall complete treatment response, clinically; versus 29.1 percent of patients on dermoscopic examination. Clinically, 45.4 percent of patients were poor/partial responders, versus 70.9 percent on dermoscopic evaluation.

When they looked at the per-lesion clinical response, researchers found nearly 27 percent of lesions had a poor/partial response and 73.1 percent a complete response. Dermoscopic evaluation, per lesion, revealed 46.5 percent of actinic keratoses treated had a poor/partial and 53.5 percent were complete responses.

The authors suggest the discrepancy between clinical and dermoscopic findings could be explained by the greater diagnostic accuracy with dermoscopy and the short follow-up of one month post-treatment.

The authors cite papers that suggest actinic keratoses should be thought of as malignant neoplasms, which, if untreated, could metastasize. Histopathologic and molecular studies suggest actinic keratoses should be viewed as an early form of superficial squamous cell carcinoma; although, the risk of progression isn’t clear, ranging in studies from 0.1 percent to 20 percent, they write.

Treatment of all of these lesions is proposed because it’s impossible to predict which actinic keratoses will become invasive squamous cell carcinoma, according to the authors.

This study, they conclude, might help clinicians to better optimize actinic keratosis treatment with ingenol mebutate 0.015% gel.

DISCLOSURES

LeoPharma supported the study.

REFERENCES

Pampena R, Benati E, Borsari S, et al. “Tracking actinic keratosis of face and scalp treated with 0.015% ingenol mebutate to identify clinical and dermoscopic predictors of treatment response,” Journal of the European Academy of Dermatology Venereology. Jan. 22, 2018. DOI: 10.1111/jdv.14803.