9127 Background: A papulopustular reaction occurs in 68–75% of patients undergoing treatment with the epidermal growth factor receptor (EGFR) inhibitor erlotinib, necessitating dose modification or interruption in 14% and 12% of patients, respectively. Based on preclinical data showing that EGFR inhibition in the skin may potentiate the harmful effects of ultraviolet radiation (UVR) exposure, sun protection is generally advocated. Because the level of melanin, a biological pigment in the epidermis, correlates with increased intrinsic protection against the harmful effects of UVR, we hypothesized that lower levels of skin pigmentation would be associated with higher frequency and severity of erlotinib rash. Methods: We conducted a retrospective chart review of 42 patients undergoing erlotinib therapy to characterize the relationship between skin sensitivity to UVR and severity of EGFR inhibitor rash. Skin sensitivity to UVR was categorized using the Fitzpatrick skin phototype (SPT) classification scheme, and individuals were grouped in phototypes I/II, III/IV, and V/VI. Grading of rash was performed using the NCI-CTC criteria version 2.0 and 3.0. Results: Patients with SPT I/II developed rash grades 0 (6%), 1/2 (31%), and 3/4 (63%), whereas patients with skin phototype III/IV had rash grade 0 (26%), 1/2 (68%), and 3/4 (5%). Patients with SPT V/VI had rash grade 0 (43%), 1/2 (57%), and 3/4 (0%). Lower skin phototypes had higher grade rash (p=0.0006 by Fisher's exact test). Conclusions: Management of cutaneous side effects from EGFR inhibitors is important in order to achieve maximal patient compliance and anti-cancer therapeutic benefit, and the correlation between rash and survival underscores maintaining patients on therapy. The results of this study suggest that SPT may be an independent predictive factor for EGFR inhibitor-induced skin toxicities, thus impacting pre-therapy counseling and early intervention. [Table: see text]
Visible light and human skin pigmentation: The importance of skin phototype
