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Therapy is based on the location of the tumor, gene classification, and disease prognosis. It’s also critical to know the stages of colorectal cancer. Staging occurs during diagnosis, and ranges from early-stage disease to stage IV cancer, which means the cancer cells have already spread to distant sites in the body. The stage of disease impacts colorectal cancer survival rates. 

Some patients' cases are discussed at a multidisciplinary tumor board — a conference attended by many doctors with different specialties that might be required for your care.

Five types of treatment are commonly used for colon and rectal cancers: surgery, ablation, radiation, chemotherapy, targeted therapy.


Fergal Fleming MDThis is the most common treatment for any stage of colorectal cancer, but the type of surgery often depends on factors such as stage, size, and location of the tumor, and the overall health of the patient. It's important to understand the goal of colorectal cancer surgery and the various options.

Possible colon cancer surgeries include:

  • Resection of the colon with anastomosis. A doctor removes the cancer and some of the surrounding healthy tissue and nearby lymph nodes, called a partial colectomy. Afterward, the surgeon performs an anastomosis by sewing the healthy parts of the colon together. This type of surgery is for larger tumors.
  • Resection of colon with colostomy. This is similar to the procedure described above. However, if the surgeon is unable to sew the healthy colon back together, an opening is made on the outside of the body for waste to pass through. A colostomy is needed if the lower colon is affected by the cancer. Sometimes a colostomy can be reversed once the lower colon heals. 

Side effects of colon cancer surgery usually depend on the patient’s health before surgery and the type of operation performed. Significant lifestyle changes are required for a temporary or permanent colostomy, and it takes time to adjust. Wilmot offers colostomy support through a program in the Department of Urology at URMC. 

Possible rectal cancer surgeries include:

  • Local excision, which removes superficial cancers in a manner similar to colon cancer local excision, without cutting through the abdominal wall.
  • Local transanal resection or transanal endoscopic microsurgery (TEM). Both of these operations are used to remove early-stage cancers without opening the abdominal wall—but the type of surgery depends on the location of the tumor. A local transanal resection is performed if the cancer is near the anus, and the TEM is for cancers located higher in the rectum. TEM requires special training, equipment and experience, and Wilmot has surgeons who are well-versed in this and other minimally invasive colorectal cancer procedures.
  • Low anterior resection. This procedure is used for rectal tumors near the colon. The surgeon removes the cancer and part of the rectum and then reconnects the colon, allowing bowels to move in the usual way.
  • Proctectomy. This procedure is for rectal tumors located in the middle or lower third of the rectum, and requires removal of the rectum. Surgeons can then perform a colo-anal anastomosis, reconnecting the colon to the anus.
  • Abdominoperineal resection. This is a more involved surgery to remove tumors in the lower third part of the rectum and the sphincter muscle. Most patients also need a permanent colostomy to give the stools a path out of the body.
  • Diverting colostomy. This is for patients with cancer that has spread and for tumors blocking the rectum.
  • Pelvic exteneration. When rectal cancer is growing into nearby organs such as the bladder, prostate or uterus, this extensive operation may be recommended. A permanent colostomy and sometimes a urostomy (to create a pouch for urine) are also part of this procedure.

Side effects of rectal surgery are similar to colon cancer surgery and can require lifestyle changes. Sexual function and fertility can be impacted by the more extensive surgeries. It's important to talk to your doctor and learn the facts before surgery.


Radiofrequency ablation can be used to kill cancer cells with tiny electrodes. Sometimes it is used if the cancer has spread to the nearby liver or other abdominal organs.


Chemotherapy uses drugs or combinations of drugs—given intravenously or as pills—to destroy cancer cells. Chemo can be given before or after surgery. When the cancer is in an advanced stage, chemotherapy may be the primary treatment. If colorectal cancer has spread to the liver, chemoembolization of the hepatic artery may be used. This type of therapy involves injecting anti-cancer drugs directly into the liver.

Radiation therapy

Radiation therapy uses energy from radiation beams, radio isotopes, or charged particles to target tumors and to eradicate cancer cells. Radiation therapy can be used to target cancer cells left behind after surgery, or to relieve symptoms in advanced cases of colorectal cancer.

Chemo-radiation therapy

This is a newer, combination therapy that can be done before surgery. In some instances it will be the primary treatment, enabling rectal preservation. Patients are monitored closely after the treatment.

Targeted therapy

These are newer drugs designed to target specific gene changes that result in colon or rectal cancer. They single out cancer cells without harming normal cells and usually have less severe side effects compared to chemotherapy. Sometimes chemotherapy is combined with newer, targeted treatments to achieve remission. 

The types of targeted therapies used in colorectal cancer include Avastin, Cyrmaza, Zaltrap, and Erbitux. Scientists are discovering more genes linked to colorectal cancer and searching for additional treatments to target those genes. In cases where the disease is more advanced and other treatments have not worked, doctors are testing drugs that can extend a patient's life.

Wilmot tests all colon cancer tissue samples to find out what genes are fueling the malignancy and if an inherited gene syndrome is present.

Side effects

Many cancer treatments cause side effects such as hair loss or fatigue. Some people have side effects and others don't. 

Wilmot's Cancer Control & Survivorship Program is one of the oldest and most highly regarded research programs in the country to investigate the management of side effects. 

The American Cancer Society also offers free online resources to help patients manage the side effects of their illness.