Radiotherapy utilization in BRAF mutation‐tested metastatic melanoma in the targeted therapy era

Aim Tumor BRAF mutation testing is routine for all patients with metastatic melanoma ( MM ) owing to the availability of agents targeting this intracellular pathway. To test whether there is a difference in radiotherapy ( RT ) utilization according to BRAF mutation status, we performed a retrospective review of RT utilization in a contemporary cohort undergoing BRAF mutation testing. Methods Clinical records of MM patients undergoing BRAF mutation testing between A pril 2010 and A ugust 2012 were reviewed. Overall survival ( OS ) was calculated using K aplan– M eier methods. Differences between BRAF status were calculated using chi‐square tests for categorical variables, median tests for continuous variables and C ox proportional hazards models to compare OS . Results Up to 158 patients were identified but 17 were excluded due to inadequate clinical data. Of the remaining 141 patients, 69 (49%) tested BRAF mutant ( BRAF ‐m), median age 47 years (range 21–79) with median follow‐up of 16.8 months ( IQR 11.3–25.2). Seventy‐two (51%) tested BRAF wild type ( BRAF ‐w), median age 62 years (range 25–84) with median follow‐up of 27.1 months ( IQR 12.5–57.4). Overall, RT utilization was similar: 68% in BRAF ‐m and 69% in BRAF ‐w. Mean number of treatment courses was 1.70 for BRAF ‐m and 2.36 for BRAF ‐w (Pearson chi‐square 3.92, P  = 0.05). Up to 51% of BRAF ‐m and 56% of BRAF ‐w required ≧2 RT courses. Forty‐six percent BRAF ‐m compared with 29% BRAF ‐w received brain RT ( P  = 0.04). Median OS was 17.7 months ( IQR 7.6–35.5) in BRAF ‐m and 19 months ( IQR 7.8–35.1) in BRAF ‐w ( P  = 0.99). Conclusion High RT utilization rates were observed irrespective of BRAF mutation status. Significantly more BRAF ‐w patients received RT but more BRAF ‐m patients received brain RT .