How effective is a proctocolectomy for treating colon cancer?

Very effective: In order to potentially cure a colorectal carcinoma by surgery, one must resect the bowel, the mesocolon/mesorectum and get proximal and distal margins around the tumor. If the lesion is very low in the rectum or rectosigmoid and getting below the lesion virtually compromises the levator ani sphinctor muscles then procto colectomy is employed.