In the staging of rectal cancer, we generally use the TNM staging system clinically. "T" refers to the primary tumor, "N" indicates whether there is lymph node metastasis, and staging is based on the status of the lymph nodes. "M" indicates whether there is distant metastasis. Stage IV refers to any stage of "T" and any stage of "N", as long as there is distant metastasis, such as rectal cancer metastasizing to the liver, lungs, or bones. When these distant organ metastases occur, the staging is M1, any "T", any "N", M1. This scenario is stage IV, indicating the presence of distant organ metastasis and represents advanced stage rectal cancer patients.