A Prospective Cohort Study of Advanced Colorectal Cancer Treated With Oxaliplatin and Irinotecan.

This study follows people with advanced colorectal cancer (bowel cancer that has spread) who were previously treated with two standard chemotherapy drugs — oxaliplatin and irinotecan — but had to stop because the cancer kept growing or the side effects became too much. Researchers want to learn more about what treatments work best after these first-line drugs stop working. **You may be eligible if...** - You have been diagnosed with colorectal cancer (confirmed by a biopsy) - You previously received oxaliplatin and irinotecan but stopped due to cancer progression or intolerable side effects - You are in reasonably good health and able to carry out daily activities - Your doctors estimate you have more than 3 months to live - You are willing to be followed up over time **You may NOT be eligible if...** - You have already received certain newer treatments (regorafenib, fruquintinib, TAS-102, PD-1 inhibitors, or targeted drugs for HER2/BRAF/NTRK) - You have previously been re-treated with oxaliplatin or irinotecan after they stopped working - You are already in another active clinical trial - You have had an organ transplant or stem cell transplant from a donor - You have another active cancer (other than certain early-stage skin cancers) Talk to your doctor to see if this trial is right for you.