Find out about rectal cancer symptoms, causes and prevention. Learn about treatments, including chemotherapy, radiation and surgery.
Rectal cancer is cancer that begins in the rectum. The rectum is the last several inches of the large intestine. It starts at the end of the final segment of your colon and ends when it reaches the short, narrow passage leading to the anus.
Cancer inside the rectum (rectal cancer) and cancer inside the colon (colon cancer) are often referred to together as "colorectal cancer."
While rectal and colon cancers are similar in many ways, their treatments are quite different. This is mainly because the rectum sits in a tight space, barely separated from other organs and structures. The tight space can make surgery to remove rectal cancer complex.
In the past, long-term survival was uncommon for people with rectal cancer, even after extensive treatment. Thanks to treatment advances over the last few decades, rectal cancer survival rates have greatly improved.
Signs and symptoms of rectal cancer include:
Make an appointment with your doctor if you have any persistent symptoms that worry you.
Rectal cancer begins when healthy cells in the rectum develop changes (mutations) in their DNA. A cell's DNA contains the instructions that tell a cell what to do.
The changes tell the cells to grow uncontrollably and to continue living after healthy cells would die. The accumulating cells can form a tumor. With time, the cancer cells can grow to invade and destroy healthy tissue nearby. And cancerous cells can break away and travel (metastasize) to other parts of the body.
For most rectal cancers, it's not clear what causes the mutations that cause the cancer to form.
In some families, gene mutations passed from parents to children increase the risk of colorectal cancer. These mutations are involved in only a small percentage of rectal cancers. Some genes linked to colorectal cancer increase the risk of developing the disease, but they don't make it inevitable.
Two well-defined genetic colorectal cancer syndromes are:
Genetic testing can detect these and other, rarer inherited colorectal cancer syndromes. If you're concerned about your family history of colon cancer, talk to your doctor about whether your family history suggests you have a risk of these conditions.
Factors that may increase the risk of rectal cancer are the same as those that increase the risk of colon cancer. Colorectal cancer risk factors include:
To reduce your risk of colorectal cancer, consider trying to:
Talk to your doctor about cancer screening. Colorectal cancer screening reduces the risk of cancer by identifying precancerous polyps in the colon and rectum that could develop into cancer. Ask your doctor when you should begin screening. Most medical organizations recommend starting screening around age 50, or earlier if you have risk factors for colorectal cancer.
Several screening options exist — each with its own benefits and drawbacks. Talk about your options with your doctor, and together you can decide which tests are appropriate for you.
Rectal cancer can be found during a screening test for colorectal cancer. Or it may be suspected based on your symptoms. Tests and procedures used to confirm the diagnosis include:
Removing a sample of tissue for testing (biopsy). If any suspicious areas are found, your doctor can pass surgical tools through the colonoscope to take tissue samples (biopsies) for analysis and remove polyps.
The tissue sample is sent to a lab to be examined by doctors who specialize in analyzing blood and body tissues (pathologists). Tests can determine whether the cells are cancer, whether they're aggressive and which genes in the cancer cells are abnormal. Your doctor uses this information to understand your prognosis and determine your treatment options.
Once you're diagnosed with rectal cancer, the next step is to determine the cancer's extent (stage). The stage of your cancer helps determine your prognosis and your treatment options.
Staging tests include:
Your doctor uses information from these tests to assign your cancer a stage. The stages of rectal cancer are indicated by Roman numerals that range from 0 to IV. The lowest stage indicates cancer that is limited to the lining of the inside of the rectum. By stage IV, the cancer is considered advanced and has spread (metastasized) to other areas of the body.
Rectal cancer treatment often involves a combination of therapies. When possible, surgery is used to cut away the cancer cells. Other treatments, such as chemotherapy and radiation therapy, may be used after surgery to kill any cancer cells that remain and reduce the risk that cancer will return.
If surgeons are concerned that the cancer can't be removed completely without hurting nearby organs and structures, your doctor may recommend a combination of chemotherapy and radiation therapy as your initial treatment. These combined treatments may shrink the cancer and make it easier to remove during an operation.
Rectal cancer is often treated with surgery to remove the cancer cells. Which operation is best for you depends on your particular situation, such as the location and stage of your cancer, how aggressive the cancer cells are, your overall health, and your preferences.
Operations used to treat rectal cancer include:
Removing very small cancers from the inside of the rectum. Very small rectal cancers may be removed using a colonoscope or another specialized type of scope inserted through the anus (transanal local excision). Surgical tools can be passed through the scope to cut away the cancer and some of the healthy tissue around it.
This procedure might be an option if your cancer is small and unlikely to spread to nearby lymph nodes. If a lab analysis finds that your cancer cells are aggressive or more likely to spread to the lymph nodes, your doctor may recommend additional surgery.
Removing all or part of the rectum. Larger rectal cancers that are far enough away from the anal canal might be removed in a procedure (low anterior resection) that removes all or part of the rectum. Nearby tissue and lymph nodes are also removed. This procedure preserves the anus so that waste can leave the body normally.
How the procedure is performed depends on the cancer's location. If cancer affects the upper portion of the rectum, that part of the rectum is removed and then the colon is attached to the remaining rectum (colorectal anastomosis). All of the rectum may be removed if the cancer is located in the lower portion of the rectum. Then the colon is shaped into a pouch and attached to the anus (coloanal anastomosis).
Removing the rectum and anus. For rectal cancers that are located near the anus, it might not be possible to remove the cancer completely without damaging the muscles that control bowel movements. In these situations, surgeons may recommend an operation called abdominoperineal resection (APR) to remove the rectum, anus and some of the colon, as well as nearby tissue and lymph nodes.
The surgeon creates an opening in the abdomen and attaches the remaining colon (colostomy). Waste leaves your body through the opening and collects in a bag that attaches to your abdomen.
Chemotherapy uses drugs to destroy cancer cells. For rectal cancer, chemotherapy might be recommended after surgery to kill any cancer cells that might remain.
Chemotherapy combined with radiation therapy might also be used before an operation to shrink a large cancer so that it's easier to remove with surgery.
Chemotherapy can also be used to relieve symptoms of rectal cancer that can't be removed with surgery or that has spread to other areas of the body.
Radiation therapy uses powerful energy sources, such as X-rays and protons, to kill cancer cells. In people with rectal cancer, radiation therapy is often combined with chemotherapy that makes the cancer cells more likely to be damaged by the radiation. It can be used after surgery to kill any cancer cells that might remain. Or it can be used before surgery to shrink a cancer and make it easier to remove.
When surgery isn't an option, radiation therapy might be used to relieve symptoms, such as pain.
Combining chemotherapy and radiation therapy (chemoradiotherapy) makes cancer cells more vulnerable to radiation. The combination is often used for larger rectal cancers and those that have a higher risk of returning after surgery.
Chemoradiotherapy may be recommended:
Targeted drug treatments focus on specific abnormalities present within cancer cells. By blocking these abnormalities, targeted drug treatments can cause cancer cells to die.
Targeted drugs are usually combined with chemotherapy. Targeted drugs are typically reserved for people with advanced rectal cancer.
Immunotherapy is a drug treatment that uses your immune system to fight cancer. Your body's disease-fighting immune system may not attack your cancer because the cancer cells produce proteins that help them hide from the immune system cells. Immunotherapy works by interfering with that process.
Immunotherapy is usually reserved for advanced rectal cancer.
Palliative care is focused on providing relief from pain and other symptoms of a severe illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care.
Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.
A diagnosis of cancer can be overwhelming. With time you'll find ways to cope with the distress and uncertainty of cancer. Until then, you may find that it helps to:
Find someone to talk with. Find a good listener who is willing to listen to you talk about your hopes and fears. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.
Ask your doctor about support groups in your area. Or check with local and national cancer organizations, such as the National Cancer Institute or the American Cancer Society.
If your doctor suspects that you may have rectal cancer, you'll likely be referred to one or more specialists who treat rectal cancer, including:
Here are some things you can do before you meet with these doctors:
For rectal cancer, here are some questions you may want to ask:
June 11th, 2021
