The Epidermal Growth Factor Receptor Inhibitor-Related Skin Toxicity Index (EGFRISTI): A New Tool for Grading and Managing Skin Adverse Reactions to Epidermal Growth Factor Receptor Inhibitors.

Background: Skin toxicity is frequent and debilitating in oncologic patients treated with epidermal growth factor receptor inhibitors (EGFRIs). Grading and management of skin adverse events (AEs) are poorly standardized. Materials and Methods: We developed a new score (EGFRISTI: Epidermal Growth Factor Receptor Inhibitor-Related Skin Toxicity Index) which is able to quantify and monitor all EGFRI-related dermatologic AEs over time. The utility of this tool was validated in 130 patients treated with 5 different EGFRIs including both monoclonal antibodies and tyrosine kinase inhibitors. Results: The mean baseline EGFRISTI score was 26.9 (range: 6.0-64.5). Mild toxicity was found in 55 patients (42.3%), moderate toxicity in 43 (33.1%), and severe toxicity in 32 patients (24.6%). After the first-line toxicity treatment, an EGFRISTI score reduction of >75% was obtained in 31 patients (34.1%) and one of 50% in 40 patients (43.9%), while an improvement of <50% was observed in the remaining 20 subjects (22.0%). Conclusions: The EGFRISTI is a simple and reliable tool to quantify and express the severity of all clinical signs and symptoms of EGFRI skin toxicity with a single numerical value, to choose the most suitable therapy, and to measure its efficacy.