Rectal Cancer

More than 95% of colorectal cancers are adenocarcinomas. The remainder are rare tumors that can also start in the colon, some of which are detailed below.

Adenocarcinomas

Adenocarcinomas begin in the mucus-forming cells that lubricate the inner surface of the rectum. 

Carcinoid tumors

These rare tumors start in the cells that make hormones inside the intestine. See gastrointestinal carcinoid tumors for details.

Lymphomas

Very rarely do lymphomas start in the rectum. It’s much more common for this cancer of the immune system cells to start in the lymph nodes.

Sarcomas

Also rare, sarcomas can start in the wall of the rectum. For more on this, refer to soft tissue sarcoma.

Researchers don’t know what causes rectal cancer, but various factors may raise the risk.

In the United States, the most common rectal cancer risk factors can be categorized as controllable and non-controllable.

Controllable risk factors

• Obesity and being overweight
• Frequently eating red meats or processed meats
• Lack of physical activity
• Smoking, especially long-term
• Heavy alcohol use (more than two drinks per day) 

Non-controllable risk factors

Age

The risk of developing rectal cancer increases after age 50.

History of colorectal polyps

People who have a history of adenomatous polyps, or who have had colorectal cancer before, have an increased risk.

Inflammatory bowel disease

Inflammatory bowel diseases, such as ulcerative colitis or Crohn’s disease, cause inflammation in the lining of the colon, which raises the risk of cancer.

Family history

Having a family history of rectal or colon cancer, or adenomatous polyps, is linked to an increased risk.

Inherited gene mutations

A small percentage of rectal cancers may be linked to genetic mutations passed down in families.

Talk to your doctor about your risk and whether you should consider genetic counseling.

Rectal cancer is one of the most preventable cancer types, and Scripps physicians aim to detect and treat rectal cancer at its earliest stages — often before abnormal cells become cancerous. A National Cancer Institute study showed that nearly 90% of U.S. patients survived five years or longer after an early-stage rectal cancer diagnosis and treatment.

Screening exams can detect rectal cancer when treatment is most likely to be successful. Pre-cancerous polyps and small tumors that have not spread often can be removed during a screening procedure.

Most people should begin having rectal cancer screenings at age 50. If you have an increased risk of rectal cancer, your doctor may recommend that you begin screening sooner or have screening exams more often.

There are several types of rectal cancer screening tests and procedures. Your physician will let you know which screening is most appropriate for you, and how often to have it. The most common screenings include:

Colonoscopy

During a colonoscopy, the physician inserts a flexible, lighted tube with an attached camera through the patient’s anus to examine the rectum and the entire colon while the patient is under sedation. This is the most thorough screening exam, and it often allows the doctor to remove polyps at the same time.

Flexible sigmoidoscopy

During a flexible sigmoidoscopy, the physician inserts a flexible, lighted tube with an attached camera through the patient’s anus to examine the rectum and lower part of the large intestine (sigmoid colon) while the patient is under sedation. 

High-sensitivity fecal occult blood test (FOBT)

This test checks for hidden blood in three consecutive stool samples.

Digital rectal exam

A physician inserts a gloved finger into the rectum to feel for abnormalities, such as polyps.

If you’re 50 or older and haven’t been screened yet, be sure to make an appointment as soon as possible.

Having any of the following symptoms does not mean you have rectal cancer. Stomach viruses, infections and the flu often cause similar symptoms. But if your symptoms persist or become worse, let your doctor know so that you can find the cause and any potential health problems.

• A change in bowel habits — such as diarrhea, constipation or narrowing of the stool — that lasts for more than a few days
• Feeling the need to have a bowel movement, even after you have had one
• Bleeding from the rectum with bright red blood
• Blood in the stool
• Cramping or abdominal pain
• Weakness and fatigue
• Unintended weight loss
• Low red blood cell counts (anemia) caused by blood loss through the rectum

In addition to rectal cancer screening exams, Scripps physicians may use other tests and procedures to detect and diagnose the disease, and determine the most effective treatment. These tests include:

Biopsy

Biopsy involves removal of a small sample of suspicious tissue. The sample, which can be taken during a colonoscopy or sigmoidoscopy, is tested and examined by pathologists in a lab.

Computed tomography (CT) scan

A CT scan is a form of X-ray imaging test that captures images of the body from different angles. The images are combined to create detailed cross-sectional views of organs, bones and blood vessels.

Magnetic resonance imaging (MRI)

MRI relies on a powerful magnet, radio waves and advanced digital technology to provide detailed images of organs, bone and soft tissue.

Positron emission tomography (PET) scan

A PET scan involves imaging after the patient swallows a type of radioactive sugar that existing cancer cells will quickly absorb so they can be identified under a special camera. This scan combined with a CT scan to give physicians the ability to view a picture of potentially cancerous areas through the PET while also seeing more detailed images from a CT scan.

Endorectal ultrasound

Endorectal ultrasound uses an instrument inserted into the anus and rectum with a probe at its end that emits ultrasound (high-energy) waves. These waves pass through soft tissues and bounce off dense tissues and organs to create an image known as a sonogram.

Complete blood count (CBC)

A CBC blood test measures the total amount of red blood cells and white blood cells, hemoglobin, and percentage of red blood cells (hematocrit).

The wall of the large intestine has several layers, as well as numerous blood and lymph vessels. Rectal cancer stages indicate how far the cancer may have grown into the wall of the intestine and beyond to other parts of the body. This helps doctors determine the best course of treatment.

Stage 0

Stage 0 rectal cancer is when abnormal cells are found in the mucosa (innermost layer) of the colon wall. These abnormal cells may become cancer. Stage 0 is also called carcinoma in situ.

Stage I

Stage I rectal cancer is when cancer has formed in the mucosa (innermost layer) of the rectum wall and has spread to the next layer of tissue under the mucosa. Cancer may have spread to the muscle layer of the rectum wall.

Stage IIA

Stage IIA rectal cancer is when cancer has spread through the muscle layer of the rectum wall to the outermost layer.

Stage IIB

Stage IIB rectal cancer is when cancer has spread through the outermost layer of the rectum wall, but not to nearby organs.

Stage IIC

Stage IIC rectal cancer is when cancer has spread through the outermost layer of the rectum wall to nearby organs.

Stage IIIA

• Cancer has spread through the mucosa to the next layer of tissue and may have spread to the muscle layer. Cancer has spread to at least one but not more than three nearby lymph nodes, or cancer cells have formed in tissues near the lymph nodes; or
• Cancer has spread through the mucosa to the next layer of tissue and has spread to at least four but not more than six nearby lymph nodes.

Stage IIIB

• Cancer has spread through the muscle layer of the colon wall to or through the outermost layer, but not to nearby organs. Cancer has spread to at least one but not more than three nearby lymph nodes, or cancer cells have formed in tissues near the lymph nodes; or
• Cancer has spread to the muscle layer of the colon wall or to the outermost layer, and has spread to at least four but not more than six nearby lymph nodes; or
• Cancer has spread through the mucosa to the next layer of tissue and may have spread to the muscle layer. Cancer has spread to seven or more nearby lymph nodes.

Stage IIIC

• Cancer has spread through the outermost layer of the colon wall, but not to nearby organs. Cancer has spread to at least four but not more than six nearby lymph nodes; or
• Cancer has spread through the muscle layer of the colon wall to or through the outermost layer, and has spread to seven or more nearby lymph nodes; or
• Cancer has spread through the outermost layer of the colon wall and has spread to nearby organs. Cancer has spread to one or more nearby lymph nodes, or cancer cells have formed in tissues near the lymph nodes.

Stage IVA

Stage IVA rectal cancer is when cancer may have spread through the rectum wall and to nearby organs or lymph nodes. Cancer has spread to one organ that is not near the rectum, such as the liver, or to a distant lymph node.

Stage IVB

Stage IVB rectal cancer is when cancer may have spread through the rectum wall and to nearby organs or lymph nodes. Cancer has spread to more than one organ that is not near the rectum, or into the lining of the abdominal wall.

No one wants to hear that they have cancer. You may feel frightened, overwhelmed, anxious or sad. All of these feelings are perfectly normal. The more you learn about your diagnosis and next steps, the sooner you can begin to make informed decisions about your treatment.

Questions and considerations

Your cancer care team offers a wealth of information for the many questions that come with a rectal cancer diagnosis. Here are some you might want to bring up with your physician or health insurance provider:

• Should I get a second opinion?
• How do I find a specialist?
• What is my treatment plan?
• Will I have to miss work/school?
• What are the side effects of rectal cancer treatment?
• How successful is my treatment likely to be?
• What costs will be covered by insurance?
• Which costs will I be responsible for?

Your Scripps team is here to help you find the answers you need to take an active role in your care. In addition, there are a number of community resources that provide education, information and helpful resources — often at no cost.

Learn more about the many cancer patient resources available to you and your loved ones.

At Scripps, your cancer care team includes professionals from every area of oncology medicine, including physicians, surgeons, radiation oncologists and nurses who specialize in cancer care. In most cases, you’ll be partnered with a nurse navigator, who will help coordinate your care and ensure you get the support you need throughout your treatment and recovery. Learn more about how Scripps puts you at the center of care.

For early-stage rectal cancer, surgery is usually the most effective treatment. In many cases, pre-cancerous polyps and small tumors that are detected during a screening colonoscopy can be removed during the procedure.

Treatment for more advanced rectal cancers can include a combination of surgery and chemotherapy or radiation therapy, depending on the size of the tumor, how close it is to sensitive tissues and other organs, the patient’s age and general health, and whether the rectal cancer is new or returning. 

Rectal cancer surgery

If rectal cancer has not spread to other parts of the body, surgery is usually the primary treatment. These surgeries can be traditional open surgeries or minimally invasive, such as laparoscopic surgery or robotic-assisted surgery. In many cases, our specialized surgical techniques preserve sphincter function, avoiding the need for a colostomy.

The most common rectal cancer surgeries include the following:

• Polypectomy is when Scripps physicians remove polyps while using a colonoscope inserted through the anus. It does not require an abdominal incision.
• Transanal excision is when the surgeon removes a tumor surgically through the anus.
• Proctectomy is when the surgeon removes the rectum.
• Abdomino-perineal resection is when, in advanced cases of rectal cancer, the surgeon may remove the entire rectum and anus, necessitating a permanent end colostomy.

Scripps surgeons perform these procedures using various surgical methods, depending on each patient's individual needs. These include:

Laparoscopic surgery

A laparoscope is a device with a small video camera that provides the surgeon a view inside the body. In this minimally invasive procedure, Scripps surgeons make several small incisions, then insert long instruments to remove part of the rectum and lymph nodes.

Minimally invasive robot-assisted surgery

Scripps is one of the country's only cancer treatment centers offering minimally invasive robot-assisted surgery for rectal cancer, which can result in a shorter hospital stay, faster healing and less scarring. Scripps surgeons use robotic tools inserted through small incisions. The robotic system uses a magnified 3-D high-definition camera and tiny instruments that give the surgeon greater range of mobility and dexterity than their own hands and wrists. The movements of the advanced robotic tool are completely controlled by the surgeon.

Scripps also offers a transanal minimally invasive surgery (TAMIS), an option that may be appropriate for some patients with early-stage rectal cancer. For appropriate patients, this surgical approach can avoid a formal proctectomy.

Because sphincter preservation often greatly impacts quality of life, Scripps teams strive to preserve the sphincter muscles and natural bodily functions. When that isn’t possible, a colostomy is required for the patient to pass bodily waste.

If rectal cancer has spread to nearby organs — such as the prostate, bladder, colon or gynecologic organs — those organs may be removed during surgery as well.

Radiation therapy for rectal cancer

Radiation therapy may be offered along with chemotherapy for more advanced rectal cancer either before surgery or after surgery to help reduce the risk of the cancer coming back locally. 

Scripps has the most comprehensive radiation therapy offerings in San Diego, including 3D-conformal radiation therapy and intensity-modulated radiotherapy (IMRT). 

• 3-D conformal radiation therapy allows physicians to visualize a patient’s anatomy in 3-D though the use of advanced computer software to match the radiation dose to the shape of the tumor while minimizing exposure of surrounding healthy tissues and organs.
• Intensity-modulated radiation therapy (IMRT) is an advanced form of radiation therapy that allows the radiation oncologist to specify the dose of radiation for the tumor while restricting the dose to surrounding healthy tissues. 

Chemotherapy and infusion therapy

Chemotherapy, in combination with radiation therapy, can be used before surgery or after surgery for rectal cancer, or it may be used alone as part of a treatment plan after surgery to attack any cancer cells that are invisible to the eye. It can also be used as palliative treatment for rectal cancers that have spread to other parts of the body.

Systemic and targeted therapies

Late-stage rectal cancer may be treated through systemic therapy, which spreads drugs throughout the body to treat cancer cells anywhere in the system. Systemic therapy is designed to provide palliative care and reduce symptoms and pain.

In some cases, patients may be eligible for clinical trials as part of their rectal cancer treatment plan. Talk with your physician about whether a clinical trial is right for you.

For a list of clinical trial that are currently enrolling patients, see our current list of clinical trials.

Your Scripps cancer team will develop a customized treatment plan outlining the treatments and therapies we recommend for your care. Before you begin treatment, you and your physician will review your plan together and discuss any questions or concerns you may have.

Your rectal cancer treatment plan generally includes:

• Family and medical history
• A summary of your cancer diagnosis and staging information
• Diagnostic testing completed (e.g., imaging, biopsy, lab tests)
• Plans for surgery, radiation, chemotherapy and/or other treatments
• Potential side effects of treatments
• Contact information for your cancer care team members

Along with helping you understand your course of treatment and encouraging discussion between you and your physician, your plan helps your team coordinate your care. You also can share your treatment plan with other providers who may be involved in your medical care.

Your rectal cancer care team includes health and medical professionals from a wide range of specialties. Scripps will customize your team to ensure you have the expertise and support you need. 

Your team may include:

• Gastroenterologists
• Surgeons and surgical oncologists
• Radiation oncologists
• Medical oncologists
• Registered nurses
• Nurse navigators
• Dietitians
• Oncology social workers

For specific details on Scripps' multidisciplinary approach to treatment, visit your cancer care team.

In support of our patients, survivors, their family members and the community, we host a handful of cancer support groups as well as a range of free workshops and health and wellness events on a number of topics such as:

• Nutrition
• Expressive writing
• Yoga
• Meditation

Check the current list of support offerings or contact your oncology social worker or cancer care coordinator.

For info about other cancer support groups in the San Diego community, call the American Cancer Society at 800-227-2345.

We are here for you — not only as your oncologists, but as a robust multidisciplinary team of experts who understands that your rectal cancer journey is about much more than your medical treatment. Specifically, Scripps offers a variety of patient support services to ensure your physical, psychological and emotional well-being as well as resources for dealing with the logistical and financial aspects of cancer care. Our services and resources include:

• Oncology nurses and nurse navigators with extensive clinical expertise in cancer care to help guide you and your caregivers to make informed decisions and ensure your optimal care.
• Oncology social workers specially trained to provide counseling, connect you with community and medical resources, assist with transportation and housing and coordinate care after discharge.
• Home health care services when you require skilled intermittent care in the comfort of your home.
• Nutrition and weight-maintenance services via registered dietitians of Scripps Center for Weight Management and Scripps Center for Integrative Medicine.
• Psychological and emotional care for patients and family members seeking mental health counseling from experts in psychology and psychiatry.
• Physical rehabilitation and occupational therapy services, including wound care, voice therapy and swallowing therapy, lymphedema therapy, balance and vestibular rehabilitation, yoga and more.
• Scripps Center for Integrative Medicine for patients interested in mind-body healing through acupuncture, biofeedback, herbal nutrition, massage therapy, integrative cancer care and more.
• Nondenominational spiritual care offered by our chaplains to help coordinate spiritual care with your own clergy, rabbi or spiritual advisor.
• Visiting patient services if you reside beyond San Diego and want help arranging appointments or learning more about short-term lodging.

For the full lineup of offerings, please visit our cancer patient resources section.