Treatment of Rectal Cancer, by Stage

Treatment for rectal cancer is based mainly on the stage (extent) of the cancer, but other factors can also be important.

People with rectal cancers that have not spread to distant sites are usually treated with surgery. Treatment with radiation and chemotherapy (chemo) may also be given before or after surgery.

Treating stage 0 rectal cancer

Stage 0 rectal cancers have not grown beyond the inner lining of the rectum. Removing or destroying the cancer is typically all that’s needed. You can usually be treated with surgery, such as a polypectomy (removing the polyp), local excision, or transanal resection. In rare cases, a more extensive surgery might be needed.

Treating stage I rectal cancer

Stage I rectal cancers have grown into deeper layers of the rectal wall but have not spread outside the rectum itself.

This stage includes cancers that were part of a polyp. If the polyp is removed completely during colonoscopy, with no cancer at the edges, no other treatment may be needed. If the cancer in the polyp was high grade (see Colorectal Cancer Stages), or if there were cancer cells at the edges of the polyp, you might be advised to have more surgery. More surgery may also be advised if the polyp couldn’t be removed completely or if it had to be removed in many pieces, making it hard to see if there were cancer cells at the edges (margins).

For other stage I cancers, surgery is usually the main treatment. Some small stage I cancers can be removed through the anus without cutting the abdomen (belly), using transanal resection or transanal endoscopic microsurgery (TEM). For some, a low anterior resection (LAR), proctectomy with coloanal anastomosis, or an abdominoperineal resection (APR) may be needed, depending on exactly where the cancer is located within the rectum.

Additional treatment typically isn’t needed after these operations, unless the surgeon finds the cancer is more advanced than was thought before surgery. If it is more advanced, a combination of chemo and radiation therapy is usually given. 5-FU and capecitabine are the chemo drugs most often used.

If you’re not healthy enough to have surgery, you may be treated with chemotherapy given with radiation therapy.

Treating stage II rectal cancer

Many stage II rectal cancers have grown through the wall of the rectum and might extend into nearby tissues. They have not spread to the lymph nodes.

For treatment of stage II rectal cancer that is pMMR or MSS, chemotherapy, radiation therapy, and surgery are usually given, although the order of these treatments might be different for some people. Recent studies have shown that an approach called total neoadjuvant therapy (TNT) may be effective and potentially allow people from having to undergo transabdominal surgery. TNT is when a patient is treated with both chemotherapy and radiation before surgery. Here is  a common approach to treating these cancers:

• Many people get both chemo and radiation therapy (called chemoradiation) as their first treatment. The chemo given with radiation is usually either 5-FU or capecitabine .
• This may be followed by more chemotherapy (without radiation) for several months. The chemo may be the FOLFOX regimen (oxaliplatin, 5-FU, and leucovorin) or CAPEOX (capecitabine plus oxaliplatin) based on what’s best suited to your health needs.
• Afterward, surgery, such as a low anterior resection (LAR), proctectomy with coloanal anastomosis, or abdominoperineal resection (APR), may be done, depending on where the cancer is in the rectum. If the chemo and radiation therapy shrink the tumor enough, sometimes a transanal resection can be done instead of a more invasive LAR or APR. This might help you avoid having a colostomy. But not all doctors agree with this method, because it doesn’t let the surgeon check the nearby lymph nodes for cancer.
• Another option might be to get chemotherapy alone, followed by chemoradiation  followed by surgery.

For treatment of stage II rectal cancer that is dMMR or MSI-H, immunotherapy is preferred, but chemotherapy combined with radiation (TNT) is also an option. If you and your doctor choose to be treated with immunotherapy, it is usually given for 6 months. If there are no findings of cancer after the immunotherapy treatment by imaging and scope, no further therapy is given. If there are finding of persistent cancer after the immunotherapy treatment, combined chemo and radiation may then be given, followed by surgery.

Treating stage III rectal cancer

Stage III rectal cancers have spread to nearby lymph nodes but not to other parts of the body.

Treatment for stage III rectal cancer is very similar to that of stage II rectal cancer (see above).

Treating stage IV rectal cancer

Stage IV rectal cancers have spread to distant organs and tissues, such as the liver or lungs. Treatment options for stage IV rectal cancer is very similar to that of Stage IV colon cancer. For more details, refer to Treatment of Colon Cancer, by Stage.  For rectal cancers that don’t shrink with chemo and widespread cancers that are causing symptoms, treatment is done to relieve symptoms and avoid long-term problems, such as bleeding or blockage of the intestines. Treatments may include one or more of these:

• Removing the rectal cancer with surgery
• Surgery to create a colostomy and bypass the rectal cancer (a diverting colostomy)
• Using a special laser to destroy the cancer within the rectum
• Placing a stent (hollow metal tube) within the rectum to keep it open; this does not require surgery
• Chemoradiation therapy
• Chemo alone

Treating recurrent rectal cancer

Recurrent cancer means that the cancer has come back after treatment. It may come back near the area of the initial rectal cancer (locally) or in distant organs, like the lungs or liver. If the cancer does recur, it’s usually in the first 2 to 3 years after surgery, but it can also recur much later.

Local recurrence

If the cancer comes back in the pelvis (locally), it’s treated with surgery to remove the cancer, if possible. This surgery is often more extensive than the initial surgery. In some cases, radiation therapy may be given during the surgery (this is called intraoperative radiotherapy) or afterward. Chemo may also be given after surgery. Radiation therapy might be used as well if it was not used before.

Distant recurrence

If the cancer comes back in a distant part of the body, the treatment will depend on whether it can be removed by surgery.

If the cancer can be removed, surgery is done. Chemo may be given before or after surgery, too. When the cancer has spread to the liver, chemo may be given through the hepatic artery leading to the liver.

If the cancer can’t be removed by surgery, chemo and/or targeted therapy drugs may be used. For people with certain gene changes in their cancer cells, another option might be treatment with immunotherapy. The drugs used will depend on what drugs a person has received previously and on their overall health. If the cancer doesn’t shrink, a different drug combination may be tried.

As with stage IV rectal cancer, surgery, radiation therapy, or other approaches may be used at some point to relieve symptoms and avoid long-term problems, such as bleeding or blockage of the intestines.

These cancers can often be hard to treat, so you might also want to ask your doctor if there are any clinical trials of newer treatments that might be right for you.

For more on recurrence, see Understanding Recurrence.