Preventive effect of chemical peeling on ultraviolet induced skin tumor formation.

Background: Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photoaged skin.
Objectives: We assessed the photochemopreventive effect of several clinically used chemical peeling agents on the ultraviolet (UV)-irradiated skin of hairless mice.
Methods: Chemical peeling was done using 35% glycolic acid dissolved in distilled water, 30% salicylic acid in ethanol, 10% or 35% trichloroacetic acid (TCA) in distilled water at the right back of UV-irradiated hairless mice every 2 weeks in case of glycolic acid, salicylic acid, and 10% TCA and every 4 weeks in case of 35% TCA for totally 18 weeks after the establishment of photoaged mice by irradiation with UVA+B range light three times a week for 10 weeks at a total dose of 420 J/cm(2) at UVA and 9.6 J/cm(2) at UVB. Tumor formation was assessed every week. Skin specimens were taken from treated and non-treated area for evaluation under microscopy, evaluation of P53 expression, and mRNA expression of cyclooxygenase (COX)-2. Serum level of prostaglandin E(2) was also evaluated.
Results: All types of chemical peeling reduced tumor formation in treated mice, mostly in the treated area but also non-treated area. Peeling suppressed clonal retention of p53 positive abnormal cells and reduced mRNA expression of COX-2 in treated skin. Further, serum prostaglandin E(2) level was decreased in chemical peeling treated mice.
Conclusions: These results indicate that chemical peeling with glycolic acid, salicylic acid, and TCA could serve tumor prevention by removing photodamaged cells.
(Copyright © 2010 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.)