Cutaneous effects of BRAF inhibitor therapy: a case series

The cutaneous effects of rapidly accelerated fibrosarcoma kinase B (BRAF) inhibitors are not well understood. Squamous cell carcinoma (SCC), keratoacanthoma, and photosensitivity have been described in patients taking BRAF inhibitors. To characterize the timing and frequency of skin lesions in patients receiving BRAF inhibitor therapy, we utilized a retrospective case review of 53 patients undergoing treatment with BRAF inhibitors for 4-92 weeks of therapy. Patients were evaluated at baseline, and then followed at 4- to 12-week intervals. Charts were retrospectively reviewed, and the morphology and timing of cutaneous events were recorded. Thirty-three of the 53 charts met exclusion/inclusion criteria, 15 were treated with vemurafenib, and 18 were treated with GSK 2118436/GSK 1120212. Of 33 patients treated with BRAF inhibitor, 13 developed photosensitivity (39.4%), 10 developed actinic keratoses (30.3%), 10 developed warts (30.3%), and 6 developed SCC (18.2%). Multiple cutaneous findings were observed in the 33 patients taking BRAF inhibitors. The previously described association with SCC and photosensitivity was observed in these patients as well. Over half of the observed SCCs were invasive in nature. Photosensitivity continues to be frequent with BRAF inhibitors. Patients taking BRAF inhibitors should have regular full body skin exams. Further studies are necessary to better elucidate the rates of these adverse cutaneous effects.