Colorectal Cancer

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Treating Colon/Rectum Cancer TOPICS

Treatment of rectal cancer by stage

The main treatment for rectal cancers that have not spread to distant sites is usually surgery. Additional treatment with radiation and chemotherapy (chemo) may also be used before or after surgery.

Stage 0

At this stage the cancer has not grown beyond the inner lining of the rectum. Removing or destroying the cancer is all that is needed. You can usually be treated with a polypectomy (removing the polyp), local excision, or transanal resection and should need no further treatment.

Stage I

In this stage, the cancer has grown through the first layer of the rectum into deeper layers but has not spread outside the wall of the rectum itself.

Stage I includes cancers that were part of a polyp. If the polyp is removed completely, with no cancer in the edges, no other treatment may be needed. If the cancer in the polyp was high grade (see “How is colorectal cancer staged?”) or there were cancer cells at the edges of the polyp, more surgery may be advised. 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. Either 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 found within the rectum (these were discussed in detail in the surgery section). Additional therapy is not 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.

For some small T1 stage I rectal cancers, another option may be removing them through the anus without an abdominal incision (transanal resection or transanal endoscopic microsurgery). If the tumor turns out to have high-risk features (such as a worrisome appearance under the microscope or if cancer is found at the edges of the removed specimen), another surgery, such as those used to treat stage II cancers, may be advised. In some cases, adjuvant chemoradiation (treatment with radiation and chemo together) is advised for patients having such surgery. 5-FU is the chemo drug most often used.

If you are too sick to have surgery, you may be treated with radiation therapy. However, this has not been proven to be as effective as surgery.

Stage II

Many of these cancers have grown through the wall of the rectum and may extend into nearby tissues. They have not yet spread to the lymph nodes.

Stage II rectal cancers are usually treated with surgery such as a low anterior resection, proctectomy with colo-anal anastomosis, or abdominoperineal resection (depending on where the cancer is in the rectum), along with both chemo and radiation therapy. Most doctors now favor giving the radiation therapy along with chemo before surgery (neoadjuvant treatment), and then giving additional chemo after surgery, usually for a total of 6 months of treatment (including the time getting chemo and radiation together). The chemo given with radiation is usually either 5-FU or capecitabine (Xeloda). The chemo after surgery 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.

If neoadjuvant therapy shrinks the tumor enough, sometimes a transanal full-thickness rectal resection can be done instead of a more invasive low anterior resection or abdominoperineal resection. This may allow the patient to avoid a colostomy. A problem with using this procedure is that it doesn't allow the surgeon to see if the cancer has spread to your lymph nodes or further in your pelvis. For this reason, the procedure generally isn't recommended.

Stage III

These cancers have spread to nearby lymph nodes but not to other parts of the body.

Most often, radiation therapy is given along with chemo before surgery (called chemoradiation). This may shrink the cancer, often making surgery more effective for 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. The rectal tumor and nearby lymph nodes are then removed, usually by low anterior resection, proctectomy with colo-anal anastomosis, or abdominoperineal resection, depending on where the cancer is in the rectum.

In rare cases where the cancer has reached nearby organs, a pelvic exenteration may be needed. Radiation therapy and chemo are usually part of treatment as well. As in stage II, many doctors now prefer to give the radiation therapy along with chemo before surgery because it lowers the chance that the cancer will come back in the pelvis and has fewer complications than radiation given after surgery. This treatment may also make surgery more effective for larger tumors.

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, or capecitabine alone. Your doctor may recommend one of these if it is better suited to your health needs. Sometimes, this chemo is also given before the chemoradiation and surgery.

Stage IV

The cancer has spread to distant organs and tissues such as the liver or lungs. Treatment options for stage IV disease 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), treatment options include:

  • Surgery to remove the rectal lesion and distant tumors, followed by chemo (and radiation therapy in some cases)
  • Chemo, followed by surgery to remove the rectal lesion and distant tumors, usually followed by more chemo and radiation therapy
  • Chemo and radiation therapy, followed by surgery to remove the rectal lesion and distant tumors, followed by more chemo

These approaches may help you live longer and in some cases may even cure you. Surgery to remove the rectal tumor would usually be a low anterior resection, proctectomy with colo-anal anastomosis, or abdominoperineal (AP) resection, depending on where it's located.

If the only site of cancer spread is the liver, you may be treated with chemo given directly into the artery leading to the liver (hepatic artery infusion). This may shrink the cancers in the liver more effectively than if the chemo is given intravenously or by mouth.

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

  • FOLFOX: leucovorin, 5-FU, and oxaliplatin (Eloxatin)
  • FOLFIRI: leucovorin, 5-FU, and irinotecan (Camptosar)
  • CapeOX: capecitabine (Xeloda) and oxaliplatin
  • Any of the above combinations, plus either bevacizumab (Avastin) or cetuximab (Erbitux) (but not both)
  • 5-FU and leucovorin, with or without bevacizumab
  • Capecitabine, with or without bevacizumab
  • FOLFOXIRI: leucovorin, 5-FU, oxaliplatin, and irinotecan
  • Irinotecan, with or without cetuximab
  • Cetuximab alone
  • Panitumumab (Vectibix) alone
  • Regorafenib (Stivarga) alone

The choice of regimens may depend on several factors, including any previous treatments and your overall health and ability to tolerate treatment.

If chemo shrinks the tumors, 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.

Cancers that don't shrink with chemo and widespread cancers that are causing symptoms are unlikely to be cured, and treatment is aimed at relieving symptoms and avoiding long-term complications such as bleeding or blockage of the intestines. Treatments may include one or more of the following:

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

If tumors in the liver cannot be removed by surgery because they are too large or there are too many of them, it may be possible to destroy them with ablation or embolization.

Recurrent rectal cancer

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

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

If the cancer comes back in a distant site, treatment depends on whether it can be removed (resected) by surgery.

If the cancer can be removed, surgery is done. Chemo may be given before surgery (see treatment of stage IV rectal cancer for a list of possible regimens). Chemo is then given after surgery as well. When the cancer is in the liver, chemo may be given through the hepatic artery leading to the liver.

If the cancer can't be removed by surgery, chemo is usually the first option. The regimen used will depend on what a person has received previously and on their overall health. Surgery may be an option if the cancer shrinks enough. This would be followed by more chemo. If the cancer doesn't shrink with chemo, a different drug combination may be tried.

As with stage IV cancer, surgery or other approaches may be used at some point to relieve symptoms and avoid long-term complications such as bleeding or blockage of the intestines. For more on dealing with a recurrence, see our document When Your Cancer Comes Back: Cancer Recurrence.

These cancers can often be difficult to treat, so you may also want to ask your doctor if you might be eligible for clinical trials of newer treatments.


Last Medical Review: 10/15/2014
Last Revised: 11/01/2014