390P Impact of age on treatment strategies in RAS/BRAF wild-type metastatic colorectal cancer (mCRC): A prespecified subgroup analysis of the GERCOR-PRODIGE STRATEGIC-1 phase III study

Nearly half of patients (pts) with CRC are over 70 years old in clinical practice. STRATEGIC-1 compared FOLFIRI-cetuximab followed by mFOLFOX6-bevacizumab (Arm A) to OPTIMOX-bevacizumab followed by FOLFIRI-bevacizumab and EGFR monoclonal antibody +/- irinotecan (Arm B) in pts with previously untreated RAS/BRAF wild-type unresectable mCRC. To elucidate the impact of age on treatment efficacy, we evaluated duration of disease control (DDC) and overall survival (OS). A subgroup analysis of pts ≥70 years old was preplaned. Pts were divided into two age groups, <70 and ≥70 years, at the time of diagnosis. DDC and OS were expressed by the Kaplan-Meier method and compared by log-rank testing and Cox regression. In the general population (N=263), 187 pts (71%) and 76 pts (29%) were <70 and ≥70 years old, respectively. In Arm A (N=131) and in Arm B (N=132), 35 pts (27%) and 41 pts (31%) were ≥70 years old, respectively. Subgroup analysis showed that age had similar prognostic value in terms of DDC (22.0 months in younger vs 25.3 months in elderly [HR=0.91, 0.66-1.25; P=0.553]) and OS (36.5 months vs 34.9 months [HR=1.08, 0.78-1.48; P=0.648], respectively). Although OS was significantly improved in Arm A (HR=1.45, 1.02-2.08; P=0.039) in <70 pts, median OS was better in Arm B in ≥70 pts (42.1 vs 33.7 months; but statistically non-significant [P=0.161]). The effect of age on the treatment efficacy is shown in Table.Table: 390PPts <70 yearsPts ≥70 yearsArm AArm BHR (95%CI)PArm AArm BHR (95%CI)PNo.96913541DDC, median (months)22.820.91.05 (0.75-1.48)0.76422.528.90.83 (0.48-1.42)0.483OS, median (months)42.631.71.45 (1.02-2.08)0.03933.742.10.90 (0.53-1.53)0.161 Open table in a new tab These results confirm the polychemotherapy regimens efficiency associated to targeted therapies despite of the age, but elderly were underrepresented in trial compared to real life. The best choice of first-line chemotherapy in older pts remains unclear. The COLAGE GERCOR study, assessing the quality of life in elderly treated by FOLFOX-bevacizumab vs the standard first-line treatment (capecitabine-bevacizumab), and further studies are needed to better target elderly with mCRC.