Mucocutaneous toxicities from MEK inhibitors: a scoping review of the literature

Background: MEK inhibitors cause a wide spectrum of mucocutaneous toxicities which can delay or interrupt life-saving therapy. Purpose: To summarize the morphology, incidence, and clinical presentation of mucocutaneous toxicities from MEK inhibitors via a scoping review of the literature. Methods: We conducted a scoping review of the published literature, including clinical trials, retrospective and prospective studies, reviews, and case reports and series. All included literature was analyzed by a panel of pediatric and adult oncodermatologists. Results: Of 1626 initial citations, 227 articles met final inclusion criteria. Our review identified follicular reactions, ocular toxicities, xerosis, eczematous dermatitis, edema, and paronychia as the most common mucocutaneous side effects from MEK inhibitor therapy. Grade 1 and 2 reactions were the most prevalent and were typically managed while continuing treatment; however, grade 3 toxicities requiring dose reductions or treatment interruptions were also reported. Conclusion: Mucocutaneous toxicities to MEK inhibitor therapy are common and most often mild in severity. Early recognition and treatment can mitigate disruptions in oncologic therapy.