RESUMO
PURPOSE: Cutaneous toxicities are common adverse effects following epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy. Zinc deficiency causes diverse diseases, including skin toxicities. Therefore, this study aimed to investigate the role of zinc deficiency in patients with EGFR-TKI-induced skin toxicities. EXPERIMENTAL DESIGN: This retrospective study enrolled 269 patients with diverse skin disorders who visited our hospital between January 2016 and December 2017. The skin toxicity severities and plasma zinc levels of 101 EGFR-TKI-treated cancer patients were analysed and compared with those of 43 non-EGFR-TKI-treated cancer patients and 125 patients without cancer but presenting cutaneous manifestations. Additionally, the role of zinc in erlotinib-induced skin eruptions was established in a 14-day-murine model. Clinical features were further evaluated following systemic zinc supplementation in EGFR-TKI-treated cancer patients. RESULTS: EGFR-TKI-treated patients demonstrated severe cutaneous manifestations and a significant decrease in plasma zinc levels than those of the control groups. The serum zinc level and Common Terminology Criteria for Adverse Events (CTCAE) 5.0 grading of EGFR-TKI-induced skin toxicities showed a significant negative correlation (r = -0.29; p < 0.0001). Moreover, erlotinib treatment decreased the plasma zinc levels and induced periorificial dermatitis in rats confirming zinc deficiency following EGFR-TKI treatment. Zinc supplementation to the EGFR-TKI-treated cancer patients showed a significant decrease in the CTCEA grading (p < 0.0005 for mucositis and p < 0.0.0001 for all other cases) after 8 weeks. CONCLUSIONS: Skin impairment following EGFR-TKI therapy could be ameliorated through zinc supplementation. Thus, zinc supplementation should be considered for cancer patients undergoing EGFR-TKI therapy.