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 in 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 other cancers, a low anterior resection (LAR), proctectomy with colo-anal anastomosis, or an abdominoperineal resection (APR) may be done, 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.

Most people with stage II rectal cancer will be treated with chemotherapy, radiation therapy, and surgery, although the order of these treatments might be different for some people. For example, here’s 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 (Xeloda).
• This is usually followed by surgery, such as a low anterior resection (LAR), proctectomy with colo-anal anastomosis, or abdominoperineal resection (APR), 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.
• Additional chemo is then given after surgery, usually for a total of about 6 months. The chemo may be the FOLFOX regimen (oxaliplatin, 5-FU, and leucovorin), 5-FU and leucovorin, CAPEOX (capecitabine plus oxaliplatin) or capecitabine alone, based on what’s best suited to your health needs.

Another option might be to get chemotherapy alone first, followed by chemo plus radiation therapy, then followed by surgery.

For people who can’t have chemo plus radiation, surgery (such as an LAR, proctectomy with colo-anal anastomosis, or APR) might be done first. This might be followed by chemo, and sometimes radiation therapy.

Treating stage III rectal cancer

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

Most people with stage III rectal cancer will be treated with chemotherapy, radiation therapy, and surgery, although the order of these treatments might differ.

Most often, chemo is given along with radiation therapy (called chemoradiation) first. This may shrink the cancer, often making it easier to take out larger tumors. It also lowers the chance that the cancer will come back in the pelvis. Giving radiation before surgery also tends to lead to fewer problems than giving it after surgery.

Chemoradiation is followed by surgery to remove the rectal cancer and nearby lymph nodes, usually by low anterior resection (LAR), proctectomy with colo-anal anastomosis, or abdominoperineal resection (APR), depending on where the cancer is in the rectum. If the cancer has reached nearby organs, a more extensive operation known as pelvic exenteration may be needed.

After surgery, chemo is given, usually for about 6 months. The most common regimens include FOLFOX (oxaliplatin, 5-FU, and leucovorin), 5-FU and leucovorin, CAPEOX (capecitabine plus oxaliplatin), or capecitabine alone. Your doctor will recommend the one best suited to your health needs.

Another option might be to get chemotherapy alone first, followed by chemo plus radiation therapy, then followed by surgery.

For people who can’t have chemo plus radiation for some reason, surgery (such as an LAR, proctectomy with colo-anal anastomosis, or APR) might be the first treatment. This might be followed by chemotherapy, sometimes along with radiation therapy.

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 cancer depend to some extent on how widespread the cancer is.

If there’s a chance that all of the cancer can be removed (for example, there are only a few tumors in the liver or lungs), the most common treatment options include:

• Surgery to remove the rectal cancer and distant cancer, followed by chemo (and/or radiation therapy in some cases)
• Chemo, followed by surgery to remove the rectal cancer and distant cancer, usually followed by chemo and radiation therapy (chemoradiation)
• Chemo, followed by chemoradiation, followed by surgery to remove the rectal cancer and distant cancer. This might be followed by more chemotherapy.
• Chemoradiation, followed by surgery to remove the rectal cancer and distant cancer. This might be followed by chemotherapy.

These approaches may help you live longer. Surgery to remove the rectal cancer would usually be a low anterior resection (LAR), proctectomy with colo-anal anastomosis, or abdominoperineal resection (APR), depending on where it’s located.

If the only site of cancer spread is the liver, you might be treated with chemo that's put right into the artery leading to the liver (hepatic artery infusion). This may shrink the cancers in the liver better than if the chemo is given into a vein (IV) or by mouth.

If the cancer is more widespread and can’t be removed completely by surgery, treatment options depend on whether the cancer is causing a blockage of the intestine. If it is, surgery might be needed right away. If not, the cancer will likely be treated with chemo and/or targeted therapy drugs (without surgery). Some of the options include:

• FOLFOX: leucovorin, 5-FU, and oxaliplatin (Eloxatin)
• FOLFIRI: leucovorin, 5-FU, and irinotecan (Camptosar)
• CAPEOX or CAPOX: capecitabine (Xeloda) and oxaliplatin
• FOLFOXIRI: leucovorin, 5-FU, oxaliplatin, and irinotecan
• One of the above combinations, plus either a drug that targets VEGF (bevacizumab [Avastin], ziv-aflibercept [Zaltrap], or ramucirumab [Cyramza]), or a drug that targets EGFR (cetuximab [Erbitux] or panitumumab [Vectibix])
• 5-FU and leucovorin, with or without a targeted drug
• Capecitabine, with or without a targeted drug
• Irinotecan, with or without a targeted drug
• Cetuximab alone
• Panitumumab alone
• Regorafenib (Stivarga) alone
• Trifluridine and tipiracil (Lonsurf)

The choice of drugs or drug combinations depends on several factors, including any previous treatments, your overall health, and how well you can tolerate treatment.

If chemo shrinks the cancer, in some cases it may be possible to consider surgery to try to remove all of the cancer at this point. Chemo may then be given again after surgery.

If the cancer doesn't shrink, a different drug combination may be tried.

For people whose cancer cells have changes in certain genes or proteins, targeted therapy drugs might be an option.

For people whose cancers cells have high levels of microsatellite instability (MSI) or changes in one of the MMR genes, another option after initial chemotherapy might be treatment with an immunotherapy drug such as pembrolizumab (Keytruda) or nivolumab (Opdivo).

For 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

If the cancer in the liver can’t be removed by surgery because they are too big or there are too many of them, it may be possible to destroy them (partially or completely) with ablation or embolization.

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 surgery (see Treating stage IV rectal cancer above for a list of possible drug options). Chemo can be given 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.