RESUMO
PURPOSE: There are concerns regarding potential negative effects of prophylactic treatment of epidermal growth factor receptor (EGFR)-inhibitor-related rashes on metastatic colorectal cancer (mCRC) outcomes. We aimed to characterize treatment patterns of EGFR-inhibitor-induced rashes and evaluate prophylactic versus reactive approaches to rash management in relation to overall survival (OS). METHODS: Patients diagnosed with KRAS wild-type mCRC from July 2010 to June 2012 in British Columbia and prescribed cetuximab or panitumumab were reviewed to describe patterns of use of oral antibiotics and steroid creams. Using Cox regression, the relationship between prophylactic versus reactive rash management and OS was characterized. RESULTS: A total 119 patients were analyzed: median age was 63 years, 61 % were male, 34 % received cetuximab, 66 % received panitumumab, and median number of EGFR inhibitor treatment was nine cycles. Rash occurred in >90 % of patients, and reactive was favored over prophylactic treatment (66 vs. 34 %). Older patients and those with Eastern Cooperative Oncology Group (ECOG) performance status 0/1 were more likely to receive prophylactic creams (44 vs. 20 % for age <60, p = 0.01) and oral antibiotics (62 vs. 12 % for ECOG ≥2, p = 0.01), respectively. Median OS was 7.0 months. The number of treatment cycles and OS were similar in both prophylactic and reactive groups (both p > 0.05). In Cox regression, ECOG >2 correlated with worse survival (hazard ratio (HR) 22.01, 95 % confidence interval (CI) 5.25-92.30, p < 0.01). However, survival outcomes were similar between patients prescribed antibiotics prophylactically versus reactively (HR = 1.10, 95 % CI 0.43-2.80, p = 0.85), and steroid creams prophylactically versus reactively (HR = 2.00, 95 % CI 0.58-6.92, p = 0.27). CONCLUSION: Prophylactic treatment of EGFR-inhibitor-related rashes is associated with similar outcomes compared to reactive rash treatment in mCRC.