435 Epidermal ablation reduces keratinocyte cancer burden by lowering skin mutation load

Sun-exposure leads to field cancerization where all keratinocytes harbor mutations and can potentially develop into a carcinoma. Here, we investigated the relationship of skin mutation load with keratinocyte cancer risk in case-control series. Finally, epidermal ablation was tested as an intervention reduce preventing cancers. Fifteen pairs patients high versus low burden were recruited matched for age, sex phototype. Comparing normal-looking forearm these individuals, those had increased (96.4 vs 76.4 mutations/Mb, p=.017) higher number CC>TT UV specific (15 11, p=0.011). These findings suggest association between sun exposure, burden. We therefore examined if reducing would cancers C57BL/6 wild type mice exposed total 20 weeks chronic suberythermal UVB irradiation. The lower half dorsal epidermis dermabrased after 10 irradiation whereas upper left intact. Dermabrasion removed entire interfollicular epidermis, leaving hair follicles Strikingly, reduced from 19.5 non-dermabrased area 2.25 mutations/Mb (p=0.014). To evaluate efficacy on formation, utilised inducible Basal Cell Carcinoma (BCC) murine model (K14Cre/ER::Ptch1lox/+) repeated procedures above. Wholemount staining BCC biomarker, Keratin-17 (K17), revealed significant reduction K17 patches (0.35 0.07 patches/mm2). Overall, our results that occurrence by lowering load.