We retrospectively analyzed the clinical data of 121 patients who received trifluridine/tipiracil (FTD/TPI) or Regorafenib...and had the result of serum CA125 just before the treatment....There were 75 patients in the baseline CA125 normal group (group N) and 46 patients in the high group (group H)….PFS and OS were significantly shorter in group H compared to group N (PFS; 1.9 vs. 3.0 months; HR 1.576 [95%CI 1.081-2.299]; p=0.016, OS; 4.1 vs. 11.0 months; HR 2.418 [95%CI 1.634-3.576]; p<0.001)....In this retrospective analysis, baseline CA125 correlated with ascites volume in later line treatment of patients with mCRC, suggesting that increased CA125 may be a predictive and prognostic factor.