Emerging Skin Toxicities in Patients with Breast Cancer Treated with New Cyclin-Dependent Kinase 4/6 Inhibitors: A Systematic Review

Three cyclin-dependent kinases 4/6, including palbociclib, ribociclib, and abemaciclib, have been approved for the treatment of patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer. The objective of this study was to evaluate the occurrence and clinical spectrum of cutaneous adverse events in patients with breast cancer following therapy with cyclin-dependent kinase 4/6 inhibitors. A systematic literature search was performed in the PubMed, Cochrane, and EMBASE databases up to November 2020 to evaluate studies published from 2015 to 2020. Articles were selected by title, abstract, and full text as required. In addition, a manual search was performed from among the references of articles included. Forty-one articles were included with a total of 13 reported dermatologic reactions including alopecia, bullous skin rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, radiation recall and radiation dermatitis, Henoch-Schonlein purpura, cutaneous leukocytoclastic vasculitis, subacute and chronic cutaneous lupus erythematosus, histiocytoid Sweet syndrome, vitiligo-like lesions, and erythema dyschromicum perstans. Skin toxicity is an important issue because it usually affects a patient's quality of life and could lead to a discontinuation of therapies; therefore, it is of fundamental importance to recognize and adequately manage the adverse skin reactions associated with these types of drugs.