Effectiveness and safety of 0·5% colchicine cream vs. photodynamic therapy in the treatment of actinic keratosis

Trial Summary:
Effectiveness and safety of 0•5% colchicine cream vs. photodynamic therapy with methyl aminolaevulinate in the treatment of actinic keratosis and skin field cancerization of the forearms: a randomized controlled trial

The objective of the study was to evaluate the effectiveness and safety of 0•5% colchicine (COL) cream vs. methyl aminolaevulinate photodynamic therapy (MAL‐PDT) in the treatment of actinic keratoses and skin field cancerization.

36 patients were included in the study. The sample size was calculated to detect a reduction difference of more than 10% between groups and SDs of equivalent differences. Inclusion criteria: outpatients attending a public dermatology clinic at UNESP Medical School (Botucatu‐SP, Brazil), over the age of 18 years, from both sexes, with a clinical diagnosis of AK on the forearms (3–10 lesions) and had not received treatment for AK (except for sunscreen) for at least 6 months.

In the COL group, whole forearms were treated with 0•5% COL cream twice daily for 10 days. In the MAL-PDT group, first the forearm was occluded with MAL (16% strength) for 3 h. After occlusion, the whole forearm received one 8‐min PDT session using a 630‐nm wavelength light‐emitting diode. A single session was used. Follow up time period was 60 days.

The primary outcome was a reduction in AK count on the forearms 60 days after treatment. AK count was reduced in 45% of patients treated with COL and 40% of those treated with MAL‐PDT. P<0.01 for both groups, for a reduction in AK count. P = 0•56 between groups. AK count was compared according to time and to groups (over time) by a linear mixed effects model with robust covariance matrix and probability adjustment for each distribution. Post hoc analysis was performed using the sequential Sidak procedure.

Main secondary outcome was % clearance of AK’s.In the COL group, 6 patients (17%) achieved total clearance, and 16 (44%) received partial clearance (>50%). In the MAL-PDT group, 7 patients (19%) achieved total clearance and 24 patients (67%) achieved partial clearance. The difference was non-significant between the two groups.

The study concluded that a 10-day course of COL 0•5% cream and a single session of MAL‐PDT are safe and effective for treating skin field cancerization of the forearms. Side effects were minimal and similar between the groups.


Summarized by: Jonas A. Adalsteinsson, UConn Department of Dermatology