Surgery is usually the main treatment for rectal cancer. Radiation and chemotherapy are often given before or after surgery. The type of surgery used depends on the stage (extent) of the cancer, where it is, and the goal of the surgery.
Before doing surgery, the doctor will need to know how close the tumor is to the anus. This will help decide what type of surgery is done. It can also impact outcomes if the cancer has spread to the ring-like muscles around the anus (anal sphincter) that keep stool from coming out until they relax during a bowel movement.
Some early rectal cancers and most polyps can be removed during a colonoscopy. This is a procedure that uses a long flexible tube with a small video camera on the end that's put into the person’s anus and threaded into the rectum. These surgeries can be done during a colonoscopy:
When cancer or polyps are taken out this way, the doctor doesn't have to cut into the abdomen (belly) from the outside. The goal of these surgeries is to remove the cancer or polyp in one piece. If some cancer is left behind or if, based on lab tests, the tumor is thought to have a chance to spread, a more complex type of rectal surgery (see below) might be the next step.
This surgery can be used to remove some early stage I rectal cancers that are relatively small and not too far from the anus. As with polypectomy and local excision, TAE is done with instruments that are put into the rectum through the anus. The skin over the abdomen (belly) isn't cut. It's usually done with local anesthesia (numbing medicine) – the patient is not asleep during the operation.
In this operation, the surgeon cuts through all layers of the rectal wall to take out the cancer as well as some surrounding normal rectal tissue. The hole in the rectal wall is then closed.
Lymph nodes are not removed during this surgery, so radiation with or without chemotherapy might be recommended after surgery if the cancer has grown deep into the rectum, was not removed completely, or has signs of spread into the lymph system or blood vessels. Sometimes, instead of chemo and radiation, a more extensive surgery, such as low anterior resection (LAR) or abdominoperineal resection (APR) (discussed below), might be recommended and then followed with chemo and radiation.
This operation can sometimes be used for early stage I cancers that are higher in the rectum and can't be reached using the standard transanal resection (see above). A specially designed magnifying scope is put through the anus and into the rectum. This allows the surgeon to do a transanal resection with great precision and accuracy. This operation requires special equipment and surgeons with special training and experience, so it's only done at certain cancer centers.
Some stage I rectal cancers and most stage II or III cancers in the upper part of the rectum (close to where it connects with the colon) can be removed by low anterior resection (LAR). In this operation, the part of the rectum containing the tumor is removed. The lower part of the colon is then attached to the remaining part of the rectum (either right away or sometime later) so that the patient moves their bowels in the usual way.
A low anterior resection is done with general anesthesia (where the patient is put into a deep sleep). The surgeon makes several small incisions (cuts) in the abdomen. The cancer and a margin (edge or rim) of normal tissue around the cancer is removed, along with nearby lymph nodes and other tissues around the rectum.
The colon is then reattached to the remaining rectum so that a permanent colostomy is not needed. (A colostomy is needed when, instead of reconnecting the colon and rectum, the top end of the colon is attached to an opening made in the skin of the abdomen. Stool then comes out this opening.)
If radiation and chemotherapy have been given before surgery, it's common for a short-term ileostomy to be made. (This is where the end of the ileum, the last part of the small intestine, is connected to a hole in the skin of the abdomen.) This gives the rectum time to heal before stool moves through it again. In most cases, the ileostomy can be reversed (the intestines reconnected) about 8 weeks later.
Most patients spend several days in the hospital after the LAR, depending on how the surgery was done and their overall health. It could take 3 to 6 weeks to recover at home.
Some stage I and most stage II and III rectal cancers in the middle and lower third of the rectum require removing the entire rectum (called a proctectomy). The rectum has to be removed so that a total mesorectal excision (TME) can be done to remove all of the lymph nodes near the rectum. The colon is then connected to the anus (called a colo-anal anastomosis) so that the patient will pass stool in the usual way.
Sometimes when a colo-anal anastomosis is done, a small pouch is made by doubling back a short piece of colon (called a colonic J-pouch) or by enlarging a segment of the colon (called coloplasty). This small reservoir or pouch of colon provides storage for stool, like the rectum did before surgery. When special techniques are needed to avoid a permanent colostomy, the patient may need a short-term ileostomy (where the end of the ileum, the last part of the small intestine, is connected to a hole in the abdominal skin) for about 8 weeks while the bowel heals. A second operation is then done to reconnect the intestines and close the ileostomy opening.
General anesthesia (where the patient is put into a deep sleep) is used for this operation. Most patients spend several days in the hospital after surgery, depending on how it was done and their overall health. It could take 3 to 6 weeks to recover at home.
This operation is more involved than the LAR. It can be used to treat some stage I cancers and many stage II or III cancers in the lower part of the rectum (the part close to the anus). It's often needed if the cancer is growing into the sphincter muscle (the muscle that keeps the anus closed and prevents stool leakage) or the nearby muscles that help control urine flow (called levator muscles).
Here, the surgeon makes a cut or incision (or several small incisions) in the skin of the abdomen, and another in the skin around the anus. This allows the surgeon to remove the rectum, the anus, and the tissues around it, including the sphincter muscle. Because the anus is removed, a permanent colostomy is needed (the end of the colon is connected to a hole in the skin over the abdomen) to allow stool to pass.
General anesthesia (where the patient is put into a deep sleep) is used for this operation. Most people spend several days in the hospital after an APR, depending on how the surgery is done and their overall health. Recovery time at home may be 3 to 6 weeks.
If the rectal cancer is growing into nearby organs, a pelvic exenteration may be recommended. This is a major operation. The surgeon will remove the rectum as well as any nearby organs that the cancer has reached, such as the bladder, prostate (in men), or uterus (in women).
A colostomy is needed after pelvic exenteration. If the bladder is removed, a urostomy is needed, too. (This is an opening in skin of the abdomen where urine leaves the body and is held in a pouch that sticks to the skin.) It can take many months to fully recover from this complicated surgery.
Some patients have rectal cancer that has spread and is also blocking the rectum. In this case, surgery may be done to relieve the blockage without removing the part of the rectum containing the cancer. Instead, the colon is cut above the cancer and attached to a stoma (an opening in the skin of the abdomen) to allow stool to come out. This is called a diverting colostomy. It can often help the patient recover enough to start other treatments (such as chemotherapy).
If rectal cancer has spread and formed just one or a few tumors in the lungs or liver (and nowhere else), surgery might be used to remove it. In most cases, this is only done if the cancer in the rectum is also being removed (or was already removed). Depending on the extent of the cancer, this might help the patient live longer, or it could even cure the cancer. Deciding if surgery is an option to remove areas of cancer spread depends on their size, number, and location.
Possible risks and side effects of surgery depend on several factors, including the extent of the operation and a person’s general health before surgery. Problems during or shortly after the operation can include bleeding from the surgery, infections at the surgery site, and blood clots in the legs.
When you wake up after surgery, you will have some pain and will need pain medicines for a few days. For the first couple of days, you may not be able to eat or you may be allowed limited liquids, as the rectum needs some time to recover. Most people are able to eat solid food again in a few days.
Rarely, the new connections between the ends of the colon may not hold together and may leak. This can quickly cause severe belly pain, fever, and the belly to feel very hard. A smaller leak may cause you to not pass stool, have no desire to eat, and not do well or recover after surgery. A leak can lead to infection, and more surgery may be needed to fix it. It’s also possible that the incision (cut) in the abdomen (belly) might open up, becoming an open wound that may need special care as it heals.
After the surgery, you might develop scar tissue in your abdomen (belly) that can cause organs or tissues to stick together. These are called adhesions. Normally your intestines freely slide around inside your belly. In rare cases, adhesions can cause the bowels to twist up and can even block the bowel. This causes pain and swelling in the belly that's often worse after eating. Further surgery may be needed to remove the scar tissue.
Some people need a temporary or permanent colostomy (or ileostomy) after surgery. This may take some time to get used to and may require some lifestyle adjustments. If you have a colostomy or ileostomy, you will need to learn how and where to order the proper supplies and to manage it. Specially trained ostomy nurses or enterostomal therapists can help you. They'll usually see you in the hospital before your operation to discuss the ostomy and to mark a site for the opening. After your surgery they may come to your house or an outpatient setting to give you more training. There may also be ostomy support groups you can be part of. This is a good way to learn from others with first-hand experience in managing this part of the treatment.
Rectal surgery has been linked to sexual problems and quality of life issues . Talk to your doctor about how your body will look and work after surgery. Ask how surgery will impact your sex life. You and your partner should know what you can expect, for example:
If you have a colostomy, it can have an impact on body image and sexual comfort level . While it may require some adjustments, it should not keep you from having an enjoyable sex life.
For more about sexuality and fertility, see Fertility and Sexual Side Effects.
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Kelly SR and Nelson H. Chapter 75 – Cancer of the Rectum. In: Niederhuber JE, Armitage JO, Dorshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, Pa. Elsevier: 2020.
Lee DJ, Sagar PM, Sadadcharam G, Tan KY. Advances in surgical management for locally recurrent rectal cancer: How far have we come? World J Gastroenterol. 2017;23(23):4170-4180.
Libutti SK, Willett CG, Saltz LB, and Levine RA. Ch 63 - Cancer of the Rectum. In: DeVita VT, Hellman S, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 11th ed. Philadelphia, Pa: Lippincott-Williams & Wilkins; 2019.
Ma B, Gao P, Wang H, et al. What has preoperative radio(chemo)therapy brought to localized rectal cancer patients in terms of perioperative and long-term outcomes over the past decades? A systematic review and meta-analysis based on 41,121 patients. Int J Cancer. 2017 1;141(5):1052-1065.
National Cancer Institute. Physician Data Query (PDQ). Rectal Cancer Treatment. 2020. Accessed at https://www.cancer.gov/types/colorectal/patient/colorectal-treatment-pdq on February 23, 2020.
National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Rectal Cancer. V.1.2020. Accessed at https://www.nccn.org/professionals/physician_gls/pdf/rectal.pdf on Feb 23, 2020.
Orsini RG, Vermeer TA, Traa MJ, et al. Does extended surgery influence health-related quality of life in patients with rectal cancer? Dis Colon Rectum. 2015;58(2):179-185.
Rausa E, Kelly ME, Bonavina L, O'Connell PR, Winter DC. A systematic review examining quality of life following pelvic exenteration for locally advanced and recurrent rectal cancer. Colorectal Dis. 2017;19(5):430-436.
São Julião GP, Habr-Gama A, Vailati BB, et al. New Strategies in Rectal Cancer. Surg Clin North Am. 2017;97(3):587-604.
Sun V, Grant M, Wendel CS, et al. Sexual Function and Health-Related Quality of Life in Long-Term Rectal Cancer Survivors. J Sex Med. 2016;13(7):1071-1079.
Last Revised: June 29, 2020