3522 Background: In elderly CC pts, adjuvant 5FU-based chemotherapy increases overall survival (OS) and disease-free survival (DFS) (Sargent, NEJM 2001). FOLFOX4 improved DFS and OS in stage III (Andre, JCO 2009). In a pooled analysis of NSABP-C07 and MOSAIC trials, oxaliplatin/5FU-based chemotherapy was not superior to 5FU/LV in pts ≥ 70 years (Jackson Mc Cleary, ASCO 2009). Methods: We performed a subgroup analysis of pts aged ≥ 70 yrs in the MOSAIC trial, reviewing clinical characteristics, comorbidities according to Adult Comorbidity Evaluation-27, SAEs, 2nd cancer and cause of death. Results: 315 pts ≥ 70 yrs were randomized between FOLFOX4 (155 pts) and LV5FU2 (160 pts). Median follow-up was 6 yrs. DFS hazard ratio (HR) was 0.91; 95% confidence interval (CI) 0.62 to 1.34 and OS HR was 1.10; 95% CI 0.73 to 1.65. No imbalance was observed for initial characteristics. In the FOLFOX4 arm and the LV5FU2 arm, 59 and 66 pts were stage II, 38 and 42 high risk stage II (pT4 and/or < 12 lymph nodes), 96 and 9...