Rectal cancer and anal canal cancer both belong to the category of malignant tumors of the digestive system, with anal canal cancer generally considered a type of rectal cancer, primarily occurring at the anal canal close to the anus. Comparatively, anal canal cancer is somewhat more serious than rectal cancer. Clinically, the closer the tumor is to the anus, the potentially higher the malignancy, meaning more severe. However, subsequent treatment outcomes also need to be considered. Both anal canal cancer and rectal cancer can be considered for curative surgery. If the cancer is very close to the anus and an anus-preserving surgery is not feasible, further colostomy surgery may be required.