Stage I

Stage I colorectal cancer has grown through the mucosa and has spread into the muscular layer of the colon or rectum.

This means that cancerous cells have been found in:

• the innermost layer (mucosa)
• the second layer (submucosa)
• possibly the third layer (muscularis propria)

In stage I, the cancer has not spread to any lymph nodes or nearby tissue.

Surgery is often the only treatment that is needed. The most common surgeries for stage I colon cancer are:

• Polypectomy: polyps that are cancerous are removed from the wall of the colon, usually during a colonoscopy.
• Local excision removes polyps from the colon lining along with a small amount of healthy tissue. This is also done during a colonoscopy.

For cancerous polyps that are determined to be high grade, or if they were not removed completely, you may need to have further surgery to remove more of the tissue.

If the cancer was not in a polyp, the standard treatment is a partial colectomy. This surgery removes the part of the colon that has cancer, as well as lymph nodes near the area.

Transanal resection or transanal endoscopic microsurgery (TEM) removes early-stage rectal cancer through the anus

Some surgeries require an incision in the abdomen to remove the part of the rectum where the cancer was found:

• Low anterior resection (LAR)
• Proctectomy
• Abdominoperineal resection (APR)