Colorectal Cancer Treatment Options

Options for colorectal cancer treatment depend mainly on the location of the tumor in the colon or rectum and the stage of the disease. Treating colon or rectal cancer may involve surgery, chemotherapy, biological therapy, or radiation therapy. Some people have a combination of treatments. Your colorectal cancer doctor can describe your treatment choices and the expected results. Colon cancer sometimes is treated differently from rectal cancer.

Surgery for Colon and Rectal Cancers

Surgery is the most common treatment for colorectal cancer.

Colon Cancer Surgeries

• Polypectomy: A small malignant polyp may be removed from your colon or upper rectum with a colonoscope. Some small tumors in the lower rectum can be removed through your anus without a colonoscope. Sometimes, if the polyp is removed entirely during colonoscopy, no other treatment may be needed. However, a follow-up colonoscopy may be recommended to look for any other polyps. 
• Local excision: If small tumors are found on the colon's lining during a colonoscopy, a local excision will be performed to remove the cancer and a small amount of the surrounding healthy tissue. 
• Colectomy: Surgery to remove all or part of the colon. These can be done with the following procedures:
  
  • Laparoscopy: Early-stage colon cancer may be removed with the help of a laparoscope, a thin, lighted tube. The surgeon sees inside your abdomen with the laparoscope by making three or four tiny incisions into the abdomen. The tumor and part of the healthy colon are removed. Lymph nodes that are close by also may be removed, and your intestine and liver will be checked to see if the cancer has spread.
  • Open surgery: The surgeon makes a large cut into the abdomen to remove the tumor, part of the healthy colon or rectum, and some nearby lymph nodes. The surgeon checks the rest of your intestine and your liver to see if the cancer has spread.

Rectal Cancer Surgeries

How close the tumor is to the anus impacts the type of surgery performed. Common procedures for rectal cancer treatment can include: 

• Polypectomy, local transanal resection, or excision: These surgical procedures are used to remove rectal cancers in the lower rectum that are at an early stage. The surgeon removes the cancer from the rectal wall and may remove some of the surrounding rectal tissue. This method allows the doctor to remove the polyps or cancer without cutting into the abdomen (belly). 
• Transanal endoscopic surgery (TEM): This type of surgery removes larger cancers that may be higher in the rectum and more challenging to remove through local transanal resection. A specially-designed magnifying scope is inserted through the anus and into the rectum.
• Low anterior resection: For some stage I, II, and III cancers in the upper rectum, this procedure removes the part of the rectum with the tumor and reattaches the colon to the remaining portion of the rectum. This surgery requires incisions to be made through the abdomen, and a permanent colostomy is not needed.
• Proctectomy: For some stage I and many stage II and III cancers in the middle and lower rectum, this surgery removes the entire rectum so that a total mesorectal excision (TME) can be done to remove all of the lymph nodes near the rectum. Then, the colon is attached to the anus (called a colo-anal anastomosis) so that the patient will move their bowels normally.
• Abdominoperineal resection (APR): Usually performed for stage II and stage III cancers in the lower to middle rectum, this procedure removes the rectum through abdominal incisions as well as the anus and sphincter muscles through incisions around the anus. This surgery type is often needed if the cancer grows into the sphincter muscle (the muscle that keeps the anus closed and prevents stool leakage) or the nearby levator muscles that help control urine flow.
• Pelvic exenteration: This procedure is a major operation that may be recommended if the rectal cancer is growing into nearby organs. The surgeon removes the rectum and any nearby organs that cancer has reached, such as the bladder, prostate (in men), or uterus (in women).

Is a Colostomy Bag Required After Colon or Rectal Surgery?

When a section of your colon or rectum is removed, the surgeon can usually reconnect the healthy parts. However, sometimes reconnection is not possible. In this case, the surgeon creates a new path for waste to leave your body. The surgeon makes an opening (stoma) in the wall of the abdomen, connects the upper end of the intestine to the stoma, and closes the other end. The operation to create the stoma is called a colostomy. A flat bag fits over the stoma to collect waste, and a special adhesive holds it in place.

For most people, the stoma is temporary. It is needed only until the colon or rectum heals from surgery. After healing takes place, the surgeon reconnects the parts of the intestine and closes the stoma. Some people, especially those with a tumor in the lower rectum, need a permanent stoma.

Chemotherapy for Colorectal Cancers

Chemotherapy uses anticancer drugs to kill cancer cells. The drugs enter the bloodstream and can affect cancer cells all over the body. Anticancer drugs are usually given through a vein, but some may be given by mouth. You may be treated in an outpatient part of the hospital, at the doctor’s office, or at home. Rarely, a hospital stay may be needed.

The chemo regimen commonly recommended to kill colorectal cancer cells in the colon, rectum, and throughout the body is called Folfox. This well-established treatment has proven very effective for many colorectal cancer patients. Based on your stage of colorectal cancer, it can be used before surgery to shrink tumors before operating or after surgery to help kill any cancer cells that may remain in the body through the lymph system.

Radiation Therapy for Colon and Rectal Cancers

Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area and is often used for colorectal cancer patients because the cancer tends to recur in the same place it was previously found. It may be given before surgery, after surgery, or both depending on whether the cancer spread and what was found during surgery.

Your cancer care team will include a radiation oncologist who specializes in determining the right type and amount of radiation therapy that may be needed. This is based on the stage of cancer and its location in the body.

Different types of radiation therapy used to treat colon and rectal cancer: 

• External radiation: The radiation comes from a machine. The most common type of machine used for radiation therapy is called a linear accelerator. Typically, patients go to the hospital or clinic for their treatment, generally 5 days a week for several weeks.
• Internal radiation (implant radiation, High Dose Radiation (HDR), or brachytherapy): The radiation comes from radioactive material placed in thin tubes put directly into or near the tumor. The patient stays in the hospital, and the implants generally remain in place for several days. With high doses, the seeds are only inserted for a few minutes at a time before being removed. Treatments are about every two weeks for a total of about four treatments. Brachytherapy is more commonly used for rectal cancer. 
• Intraoperative radiation therapy (IORT): In some cases, radiation is given during surgery.

Immunotherapy for Colorectal Cancers

Immunotherapy, also known as biological therapy, uses the body's immune system to fight cancer. This type of cancer treatment uses materials made by the body or in a laboratory to simulate a natural substance.

A relatively new cancer treatment, immune checkpoint inhibitors, is a drug that blocks proteins called checkpoints that are made by some types of immune system cells, such as T cells and some cancer cells. The checkpoints keep the immune system from responding properly and sometimes can keep T cells from killing cancer cells. Using the inhibitor blocks the proteins to reinforce the body’s ability to fight the cancer cells.

Some people with colorectal cancer that has spread receive a monoclonal antibody that binds to colorectal cancer cells. They interrupt cancer cell growth and the spread of cancer. Patients receive monoclonal antibodies through a vein at the doctor’s office, hospital, or clinic. Some people receive chemotherapy at the same time.

Targeted Therapy for Colorectal Cancer

Targeted therapy drugs aim at specific genes, proteins, or tissues that are contributing to the cancer’s growth and blocks them while allowing healthy cells to grow with little impact. For colon cancer patients who are advanced stage or have recurring cancer, targeted therapies may be an option. 

Biomarker testing is done to see if there is a genetic mutation that can be targeted with a specific drug. These are not inherited gene mutations, but rather mutations that have been caused by other factors over time based on exposure to the environment and various foods. 

Avastin is an FDA-approved targeted therapy used to treat colorectal cancer that has returned. This may be the best therapy to use next unless the biomarker testing results show signs of a genetic mutation that can be treated by a different targeted therapy.

• Anti-angiogenesis therapy: Angiogenesis inhibitors, or unique cancer-fighting agents, stop the growth of blood vessels that support tumor growth rather than stopping the growth of tumor cells themselves. Some are monoclonal antibodies that specifically recognize and bind to VEGF (vascular endothelial growth factor), a substance made by cells that stimulate new blood vessel formation. In some cancers, angiogenesis inhibitors appear to be most effective when combined with other treatment types. Since angiogenesis inhibitors work by slowing or stopping tumor growth without killing cancer cells, they are administered over a long period.
• Epidermal growth factor reception (EGFR) inhibitors: A protein called EGFR helps cancer cells grow. Because of this, cancerous cells tend to have a lot of this protein on them. Slowing the growth of the protein slows the reproduction of colorectal cancer cells.

Clinical Trials for Colon and Rectal Cancers

Recently, many new colorectal cancer treatments have been approved and used in combination with long-standing treatments. New treatments for some types of colorectal cancer replace the first line of treatment previously given. Compass Oncology has been participating over the years in these studies and currently offers clinical trials to patients with colon cancer or rectal cancer.

A clinical trial is a carefully monitored research study meant to help introduce new treatment or improve upon current treatment options. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment, which is what we are seeing with lung cancer in the past 5 years. 

Your oncologist will discuss possible clinical trial participation if you meet a study's criteria for participation.

Learn more about the cancer clinical trials available at Compass Oncology.

Find a Colorectal Cancer Specialist in the Portland-Vancouver Area

If you have been newly diagnosed with colorectal cancer, the next step is to schedule a consultation with an oncologist. If you are in the Portland, OR, or Vancouver, WA area, we offer personalized treatment plans and second opinions on treatment. You can find a location near you to talk with an oncologist about your specific diagnosis and treatment plans.