Noninvasive Long-term Monitoring of Actinic Keratosis and Field Cancerization Following Treatment with Ingenol Mebutate Gel 0.015.

OBJECTIVE

To determine whether actinic keratosis and photodamaged perilesional areas (field cancerization) treated successfully with topical ingenol mebutate gel 0.015% remained clear one year later, and to treat actinic keratosis and perilesional skin not treated one year earlier.

DESIGN

Single-center, single-arm, open-label extension of an original clinical study completed one year earlier.

SETTING

An outpatient clinic.

PARTICIPANTS

Fifteen of the original 28 study patients enrolled in and who completed the extension phase. MEASUREMENTS: All treated and untreated lesions in the original study were evaluated clinically, dermoscopically, and with optical coherence tomography at Day 0 of the extension study. Previously untreated lesions were then treated with ingenol mebutate gel 0.015% for three days and reevaluated at Day 60.

RESULTS

There was no significant increase in actinic keratoses over one year. The majority of actinic keratoses not treated in the original study were still present at the beginning of the extension study. Following treatment, 69 percent of these lesions cleared by Day 60 of the extension study, which was not significantly different from the 79 percent clearance observed in the original study.

CONCLUSION

Ingenol mebutate 0.015% maintained clearance of lesions treated one year earlier. Optical coherence therapy demonstrated its reliability as a noninvasive mode of diagnosis for actinic keratosis as well as actinic damage in the surrounding areas of field cancerization. Optical coherence therapy also showed that previously untreated lesions exhibited similar clearance rates once treated with the medication.