Colorectal cancer is a serious disease. As far as cancers go, it is the fourth leading cause of cancer diagnosis and the second leading cause of cancer death. Colorectal cancer develops as pre-cancerous polyps or growths in the colon and rectum that eventually transform into cancer.

Rectal cancer specifically differs from colon cancer both in the location of the tumor and the types of surgery and treatment that it involves. Once you are diagnosed with rectal cancer (usually as a result of a colonoscopy or a CT scan), several factors go into determining which stage your cancer is in and what kind of treatment it will require.

Rectal Cancer Stages

Rectal cancers are classified according to five different stages. In Stage 0, cancer cells are found on the surface of the rectal lining, also called the mucosa. It may also be found within polyps. In Stage I rectal cancer, the tumor extends below the mucosa and sometimes penetrates into the rectal wall. Stage II tumors extend into or through the rectal wall, including tissues next to the rectum. Stage III tumors invade lymph nodes near the rectum as well as other structures or tissues outside the rectal wall. Stage IV tumors have spread to distant organs or lymph nodes.

Tumors are also graded based on tissue samples taken during a biopsy. High-grade tumors are quick to spread and may need more aggressive treatment, whereas low-grade tumors are slower to grow and spread.

In addition to the biopsy, staging rectal cancer usually involves several blood tests and imaging studies that can help your oncologist and surgeon determine the correct course of treatment. Tests that are typically performed include:

  • Complete blood count (CBC) to measure the numbers of different types of cells in your blood. If your red blood cell count is low, it could suggest blood loss due to the tumor. A high white blood cell count is often a sign of infection.
  • Chemistry panel that measures different chemicals in your blood. Abnormal levels of some chemicals may suggest the cancer has spread to the liver. In addition, other chemicals may indicate issues with other organs.
  • An MRI of your pelvis is often used to view muscles, organs, and other tissues surrounding a rectal tumor. It will also show the lymph nodes near the rectum and other tissues in the rectal wall.
  • CEA, or carcinoembryonic antigen tests, are used to determine whether a specific tumor marker is present in your blood. Your oncologist will likely use CEA in addition to other tests to monitor your response to treatment.
  • A CT scan of your chest and abdomen is often used to check if rectal cancer has spread to other organs in your body such as the lungs or liver.

Determining Your Rectal Cancer Risk

Rectal cancer may be detected without actually encountering symptoms, especially if it is found during a routine screening colonoscopy.

In other cases, you may notice something is wrong through low iron or blood counts causing fatigue or shortness of breath. You may notice changes in bowel habits such as constipation, diarrhea, small-calibur (pencil thin) stools, bloody stools or changes in the color of your stools. Advanced cases may even manifest as pronounced weight loss or pelvic pain.

Rectal Cancer Risk Factors

In general, patients who are diagnosed with colorectal cancers fall on a broad spectrum.

You may be at greater risk for rectal cancer if you have been diagnosed with inflammatory bowel diseases like Crohn’s disease or ulcerative colitis. In addition, there is a good chance (30%) of familial inheritance, especially with first-degree relatives who have been diagnosed with colorectal cancer.

Risk factors associated with behavior involve cigarette smoking, high alcohol use, diabetes, decreased physical activity and eating diets low in fruits or vegetables. A high fat diet that involves a lot of processed meat or red meat may also put you at greater risk for rectal cancer.

Steps to take for rectal cancer prevention involve eating a healthy, balanced diet with lots of fruits, vegetables and fiber. In addition, regular exercise and physical activity can make a difference. Finally, for average risk individuals, regular colorectal screenings (including colonoscopy) should be done starting at age 45 and continuing on per your physician’s instructions.

Treatments for Rectal Cancer

If you have been diagnosed with rectal cancer, it is important for you to understand all the treatment options available. At Memorial Hermann Health System, our team of surgical, medical and radiation oncologist’s work together to chart a treatment plan that makes sense for your individual case.

Radiation Therapy

Radiation is not commonly used to treat colon cancer, but it is used in some cases. Your doctor may pursue radiation therapy (with chemotherapy) before surgery (neoadjuvant) to help shrink a tumor for removal. It may also be used after surgery (adjuvant radiation) if the tumor has attached to other internal organs or spread. If you are not healthy enough for surgery, radiation and chemotherapy may be used to help control the spread of cancer.

Radiation therapy primarily falls into two categories: external-beam radiation therapy (EBRT) and intensity-modulated-radiation therapy (IMRT).

EBRT is the type most often for people with rectal or colon cancers and delivers radiation focused on the tumor site from a machine outside the body. Treatments can last anywhere from a few days to several weeks. Patients may consider this treatment similar to having an X-ray taken, but the radiation used is more intense.

IMRT differs from EBRT in that it allows for even more precise targeting of tumor sites and increases the local control over the dosage and delivery of radiation. This allows for smaller margins of treatment and helps to limit radiation exposure to healthy/normal tissue.

Major side effects of radiation treatment in the area of the rectum include skin and tissue irritation, fatigue, scarring, potential sexual problems and bowel and bladder irritation. Many side effects can improve throughout time, but it is always important to follow up with your Oncology Nurse Navigator or doctor with any side effects you experience during treatment.    


Chemotherapy is commonly used in the treatment of rectal cancer, often in conjunction with radiation and surgical treatment. Depending on the size and stage of the cancer, chemotherapy may be utilized before (neoadjuvant) or after surgery (adjuvant chemotherapy) to attempt to reduce the risk of relapse. Neoadjuvant chemotherapy, or chemotherapy performed prior to surgery, is commonly utilized along with neoadjuvant radiation therapy to help shrink the tumor prior to surgery.

If you undergo chemotherapy for rectal cancer,  you may experience side effects common with most forms of chemotherapy, such as myelosuppression (decrease in blood cell counts causing compromised immune systems and anemia), as well as nausea, vomiting and general reddening or ulceration in your gastrointestinal tract. Your Oncology Nurse Navigatorand medical oncologist will help explain common side effects of chemotherapy and determine when and how to address them if necessary.

Surgical Treatments for Rectal Cancer

Surgical treatments for rectal cancer range from diagnostic biopsies and polyp removal to full resections of your rectum and anus. In general, surgeries are recommended for patients who have Stage I, II, or III cancers that have not metastasized (spread).

Polypectomy and Local Excision

Much like treatment for colon cancer, a polypectomy may be used for rectal cancer treatment as your physician performs a colonoscopy. In many cases, they may be performed endoscopically with forceps or a snare biopsy technique. This procedure is usually done if your doctor notices an abnormal growth called a polyp in your colon or rectum.

Local excision treatments are slightly more involved, as small cancers on the inside lining of the rectum are removed along with a small amount of surrounding healthy tissue. These procedures are generally not as invasive as other techniques and do not require your doctor to cut into your belly.

Low Anterior Resection

In cases where the cancer is found in the middle or upper part of the rectum, your doctor may perform a surgery to remove the part of the rectum that contains the tumor and then reattach what remains to your colon, allowing for regular bowel movements. This procedure is performed under general anesthesia. The cancerous part of the rectum and its associated lymph nodes are removed.  Your colon is then reattached to the remaining rectum, and a permanent colostomy is not needed. This procedure can be done through open or laparoscopic surgery, as well as robotically.

Abdominoperineal Resection and End Colostomy

This surgery is done for patients with very low rectal cancers that are close to the anus. The rectum and anus are removed and a permanent colostomy is made. A colostomy is when the end of your colon is connected to a hole in the skin over the abdomen, allowing stool to exit the body.

Colo-Anal Anastomosis

If cancer is found in the middle and lower third of the rectum, in most cases it may require removal of the entire rectum. Once the tissue has been removed, the colon is reattached to the anus and will allow for bowel movements. Bowel function may be irregular with a coloanal anastomosis.

Surgical Side Effects and Recovery

All surgeries will have side effects such as pain and discomfort and require adjustments, especially in cases where a colostomy or ileostomy are required. In general, you will likely experience a change in bowel habits. Whereas you may have previously gone to the bathroom once per day, you might experience two to three bowel movements per day post-surgery. 

You may also experience other side effects, such as constipation and a lack of appetite. It may take several days or even weeks for you to adjust to the changes after surgery. 

Generally speaking, laparoscopic and robotic-assisted surgeries will mean shorter recovery times as they are less invasive. The prognosis for rectal cancer is generally very good, although it is dependent upon the pathologic stage of the cancer as well as your individual response to treatment.

Your Rectal Cancer Treatment at Memorial Hermann

Effective treatment for rectal cancer involves a multidisciplinary approach that Memorial Hermann Health System takes very seriously. If you are diagnosed with rectal cancer, it is important that your health providers — from colorectal surgeons, surgical oncologists, medical oncologists and radiation oncologists to support staff — work together with you to develop a treatment plan that takes you from the first stages of diagnosis to recovery and beyond.

To learn more about cancer treatment through Memorial Hermann Health System, connect with one of our Oncology Nurse Navigators via the form below. In addition to learning about treatment, we can connect you with information on affiliated providers and support services to help with your or your loved ones’ cancer diagnosis. 

Contact Us

For more information about Memorial Hermann Cancer Centers, including how to get connected to our support services or an affiliated provider, please call (833) 770-7771 or fill out the form below to be connected to one of our Oncology Nurse Navigators.


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