Skin toxicity associated with outcome to erlotinib in non-small cell lung cancer (NSCLC) patients (p) with EGFR mutations in the EURTAC study.

7542 Background: Rash is reported in 75% of p treated with erlotinib and has been associated with improved overall and progression-free survival (PFS) in unselected p although not specifically in p with EGFR mutations. Methods: The EURTAC trial (clinicaltrials.gov NCT00446225) randomized 174 p with EGFR exon 19 deletions or L858R mutations to receive erlotinib or chemotherapy. Overall PFS was 9.7 months (m) vs 5.2 m, respectively (P<0.0001). Rash was defined according to NCI CTC v3.0 and dichotomized by grades 0-1 vs 2+. Grade 2 is macular or popular eruption or erythema with pruritus or other associated symptoms, localized desquamation or other lesions covering <50% of body surface area. We examined outcome in the erlotinib arm according to rash grade. Results: 16 p in the erlotinib arm had no rash (grade 0), 30 had grade 1, and 40 had grade 2+. 80% of cases of rash grade 2+ occurred in p with exon 19 deletions, while only 20% were in p with L858R mutations (P=0.039). There were no differences in rash gr...