TAS-102 With or Without Celecoxib in ctDNA-defined Minimal Residual Disease in Colorectal Cancer After Completion of Adjuvant Chemotherapy

This study is testing whether adding celecoxib (an anti-inflammatory drug) to TAS-102 (an oral chemotherapy) can clear residual cancer signals — detected by a blood test called ctDNA — in colorectal cancer patients who finished their standard chemotherapy but still show signs of microscopic remaining disease. **You may be eligible if...** - You have been diagnosed with colorectal cancer (stage II, III, or IV) - You had successful surgery to remove all visible cancer (R0 resection) - You completed at least 3 months of oxaliplatin-based chemotherapy - A blood test (ctDNA assay) shows minimal residual disease - No cancer is visible on imaging **You may NOT be eligible if...** - You have visible cancer on imaging - You have not completed your planned curative-intent treatment - You have health conditions that prevent the use of TAS-102 or celecoxib Talk to your doctor to see if this trial is right for you.