If you have been diagnosed with rectal cancer, you probably have many questions and concerns about treatment. This patient summary, which is based on the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines™), will help you understand the best available treatments for rectal cancer. Talk to your doctor about these therapies so that together you can decide on a treatment plan that is right for you.
Background
The rectum is part of the body’s digestive system. The digestive system removes and processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from foods and helps pass waste material out of the body. The digestive system is made up of the esophagus, stomach, and the small and large intestines. The first 6 feet of the large intestine are called the large bowel or colon. The last 6 inches are the rectum and the anal canal.
Cancer of the colon or rectum is the third most frequently diagnosed cancer in men and women in the U.S. Cancer of any portion of the large intestine is sometimes collectively referred to as colorectal cancer.
Most colon and rectal cancers are believed to start as a polyp, which is a small abnormal growth in the lining of the large intestine. Polyps on stems or stalks that look like mushrooms are called pedunculated polyps. Polyps that are flat and grow directly onto the inner wall of the rectum are called sessile polyps. Sessile polyps are more difficult to remove than the stalk-like pedunculated type. However, most polyps will not turn out to be cancerous.
Diagnosis
The presence of a rectal polyp or tumor may be detected during a colonoscopy or sigmoidoscopy or other test, but only a biopsy of tissue from the polyp or tumor can be used to confirm or rule out the presence of rectal cancer.
If other members of your family have had colon or rectal cancer, make sure your doctor knows. Depending on how many and how close the family members are, your doctor may recommend genetic testing for you to determine whether you might have a genetic mutation that makes you more susceptible to colorectal cancer and genetic counseling for other members of your family.
Usually there are no symptoms of early stage rectal cancer unless the cancer has obstructed your rectum. In addition to confirming a diagnosis of cancer, your biopsy sample provides the doctor with information about:
- Whether the cancer is non-invasive (localized to layer of tissue where it began) or invasive (has spread deeper into the wall of the colon)
- The grade of the tumor cells, i.e., how much the cancer cells resemble healthy cells under a microscope. Generally, Grade 1 colon cancer cells look more like healthy cells and grow slowly while Grade 4 cells have more pronounced abnormalities and grow quickly.
Tumor stage
Staging describes the extent or severity of a cancer diagnosis. The stage of a colon cancer tumor is characterized by 3 factors:
- How deeply the tumor has penetrated into the wall of the colon
- Whether cancer has spread to surrounding lymph nodes, and if so, the number of lymph nodes affected
- Whether there is evidence of distant spread of disease (metastasis)
Stage 0 rectal cancer, also called rectal cancer “in situ” (which means “in place”), is a very early stage of disease that has not spread beyond the innermost lining of the rectum usually as a polyp. This is also referred to as non-invasive rectal cancer. It does not have the potential to spread to other parts of your body so strictly speaking, it is not classified as a malignant polyp.
Rectal cancer that is Stage I or higher is invasive rectal cancer. Stage I or Stage II disease is characterized by a tumor that has invaded into the wall of the rectum but with no lymph node involvement and no distant spread of disease. The stage of a tumor is described more precisely with a number and lettering system. For example, a rectal cancer tumor staged as IIB has penetrated more deeply into the wall of the rectum than a Stage IIA rectal cancer tumor.
The defining characteristic of Stage III rectal cancer is cancer detected in one or more surrounding lymph nodes. Stage IV rectal cancer is characterized by evidence of distant disease spread (metastasis). (View a separate summary on Colon and Rectal Cancer - Stage IV.)
It is very important that your team of doctors perform a number of tests (including an ultrasound, a magnetic resonance imaging [MRI] or a computed tomography [CT] scan of the rectum) soon after your diagnosis (and prior to surgery) to evaluate tumor stage. The information on the stage of the tumor is a particularly critical piece of information needed to direct treatment decisions for patients with rectal cancer.
Treatment
The stage of the rectal cancer is the foundation on which all NCCN treatment recommendations are based. However, you may require or choose different treatments than someone else with the same stage of cancer. Recently, tumor markers have been identified that predict whether specific systemic treatments are expected to be beneficial to you. In addition, certain treatment options may be appropriate during at one point in your disease, but not another. To make the best decisions for you, talk to your doctor about the benefits, risks, and possible side effects of the treatment options below.
Treatment for stage 0-III rectal cancer involves one or more type of treatment. Very early stage rectal cancer may be treated with surgery alone while more advanced disease likely will be treated with a combination of chemotherapy, radiation therapy, and surgery.
Your doctor should provide you with a written care plan explaining what treatments you will have, when they will occur and how often if you are receiving chemotherapy or radiation, and what type of side effects you may experience. Some of the side effects can be anticipated and you can be given pretreatment to minimize them. You will be asked to sign an informed consent indicating that you have been told about your treatment and what to expect. It is very important that you ask your doctor or nurse any questions that you have. Cancer and its treatment are complicated and most patients have questions.
Surgery
Polypectomy. This is the removal of a polyp during a colonoscopy or sigmoidoscopy examination. If the biopsy of the polyp shows that invasive cancer is present, you may or may not require additional surgery (see, 'colectomy' below). The way a polyp is managed depends on its type:
Polyps on stems or stalks that look like mushrooms are called pedunculated polyps. Polyps that are flat and grow directly onto the inner wall of the colon are called sessile polyps. Sessile polyps are more difficult to remove than the stalk-like pedunculated type.
The NCCN Guidelines
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for Rectal Cancer recommend against additional surgery for a pedunculated polyp that was removed by polypectomy if three criteria are met:
- The polyp has been completely removed in one piece
- There is no cancerous tissue at the edges of the polyp, and
- The grade of the tumor cells indicates that the tumor is likely to be slow growing.
However, additional surgery is recommended if any of these criteria are not met. The same recommendations apply if you have a sessile polyp. However, with this type, additional surgery may be considered since invasive cancer in this type of polyp is more likely to spread to nearby lymph nodes.
For polyps with non-invasive cancer, the NCCN Guidelines recommend polypectomy. If a polyp is removed in several pieces, another polypectomy scheduled several months after the initial one may be needed to ensure that the polyp has been completely removed.
Rectal surgery. Surgery is a mainstay of treatment for most patients. Such surgery involves removal of the rectal tumor (or polyp – see section on polypectomy above) as well as some healthy tissue in the vicinity of the tumor. Your doctor may recommend one type of rectal surgery for you, or you may be offered more than one surgical option, depending on such factors as the size and location of the tumor and whether cancer has spread to nearby lymph nodes.
In most types of rectal surgery, with the exception of polypectomy and transanal excision, lymph nodes in the area near the tumor are also removed. For those types of rectal surgeries, the NCCN Guidelines recommend that at least 12 lymph nodes should be removed and biopsied so that an adequate assessment of cancer spread can be made.
In many cases, if the rectal tumor has been removed by a lower anterior resection or a total mesorectal excision, your surgeon will surgically reconnect the rectum to either the rectum or the anus during the same surgical procedure, making it possible for you to have bowel movements. In some cases, the end of the rectum is connected to a collection device outside the body. Waste material is then diverted from the rectum into the collection device (i.e., colostomy bag). This may be done to allow a portion of the large intestine to rest and heal, and may be either temporary or permanent. If temporary, another surgical procedure is needed. A permanent colostomy is needed if an abdominoperineal resection is done.
Transanal excision. This type of surgery is possible for some patients with small, early-stage tumors that have not penetrated very deeply into the wall of the rectum. A transanal excision is performed through the anus; therefore, no surgical incision is made in the abdomen. Only the tumor and a section of healthy tissue around the tumor are removed; hence, the large intestine is not divided into 2 sections during surgery. Other criteria which should be met before transanal excision is considered include:
- Tumor location in a region of the rectum close enough to the anal opening to be reached by the surgical equipment,
- Low grade tumor,
- No lymph node involvement detected on imaging.
Since no lymph nodes are removed during this procedure, it is not possible for lymph node biopsies to be done following a transanal excision.
Lower anterior resection. A lower anterior resection is often used to remove a rectal tumor that is in the mid- to upper rectum (i.e., close to the colon). This procedure involves a surgical incision in the abdomen and removal of the portion of the large intestine with the rectal tumor as well as some healthy tissue on either side of the tumor. The NCCN Guidelines recommend that chemoradiation therapy (see section on Chemoradiation therapy) should be given before a lower anterior resection for patients with Stage II or Stage III rectal cancer.
Total mesorectal excision. A total mesorectal excision is an option for some patients with tumors in the lower portion of the rectum (i.e., close to the anus). A surgical incision is made in the lower abdomen and the rectum is removed as a “tumor package” along with the lymph nodes in the vicinity of the rectum. The NCCN Guidelines recommend that chemoradiation therapy (see section on Chemoradiation therapy) should be given prior to a total mesorectal excision for patients with Stage II or Stage III rectal cancer.
Abdominoperineal resection. An abdominoperineal resection is a surgical procedure used to treat some tumors in the lower portion of the rectum close to the anus. In particular, rectal tumors involving the anal sphincter (i.e., the muscle involved in closing the anus) are usually treated by this type of surgery. It involves removal of the rectum and the anus, followed by colostomy (see above). The NCCN Guidelines recommend that chemoradiation therapy (see section on Chemoradiation therapy) should be given prior to an abdominoperineal resection for patients with Stage II or Stage III rectal cancer.
Chemoradiation therapy
The NCCN Guidelines recommend that patients with Stage II and Stage III rectal cancer receive a combination of chemotherapy and radiation therapy (called chemoradiation therapy) before surgery, unless there is a medical reason why such therapy cannot be given.
Chemotherapy drugs are given to destroy cancer cells that may have spread beyond the tumor. Certain chemotherapy drugs also can make radiation therapy more effective. Radiation therapy uses high-energy beams to kill cancer cells in a particular area of the body. In the treatment of rectal cancer, radiation therapy is focused in the pelvis.
The combination of chemotherapy with radiation therapy, when administered before surgery, is especially effective in the treatment of rectal cancer. One reason for this is that a rectal cancer tumor - and the surrounding lymph nodes in the vicinity of the tumor to which cancer may have spread - is typically more difficult to completely remove than most colon cancer tumors. Chemoradiation is used to help shrink the rectal tumor so that it can be more effectively removed during surgery. It also is given to help prevent return of the cancer to the rectum, and its spread to more distant sites. A list of the chemoradiation therapy regimens that are preferred by the NCCN Panel can be viewed in the NCCN Guidelines for Rectal Cancer.
Side effects of radiation therapy to the pelvis can include diarrhea, abdominal pressure or discomfort in the rectal area, a burning sensation during urination or more frequent urination, skin irritation, nausea and fatigue, and sexual side effects. Talk to your doctor or oncology nurse before radiation therapy to discuss ways to reduce the discomfort. See Palliative Care Gets New Life.
Chemotherapy
Chemotherapy drugs are given to destroy cancer cells. If you are given chemotherapy following surgery it will be called “adjuvant” chemotherapy, typically for several months. Adjuvant means to help or assist and is given in addition to surgery to kill any cancer cells that may have spread beyond the tumor. Studies have shown that adjuvant chemotherapy for rectal cancer may increase the likelihood of long-term survival by preventing the cancer from returning.
Not everyone with rectal cancer will need to receive chemotherapy
- Chemotherapy is not recommended for those with Stage 0 or Stage I rectal cancer
- Chemotherapy is recommended for those with Stage II or III rectal cancer.
See Guide to Chemotherapy.
A specific drug or combination of drugs is typically given as adjuvant therapy for stage II and III rectal cancer even if you had preoperative chemoradiation therapy. A list of the chemotherapy regimens that are preferred by the NCCN Guidelines Panel for Rectal Cancer can be viewed in the NCCN Guidelines for Rectal Cancer (see NCCN Guidelines ). Some chemotherapy regimens have uncomfortable side effects and include hair loss, intestinal disturbances (including nausea and vomiting), numbness or pain, or a decreased production of certain types of blood cells. Talk to your doctor or oncology nurse about how to manage these effects.
If you are a premenopausal woman, your menstrual periods may stop either temporarily or permanently after you receive chemotherapy, possibly resulting in permanent infertility. Talk to your doctor about what to expect from each treatment and what can be done to help you manage or cope with these side effects.
Prognosis
In determining a prognosis—the likely course or outcome of a disease—a doctor may look at cancer survival statistics taken from studies of large groups of patients. However, such statistics:
- Are estimates only,
- Can vary widely with each cancer stage,
- Are sometimes based on older data that do not reflect recent advances in early detection and treatment,
- Cannot be used to precisely predict your survival.
Your individual prognosis will be affected by many factors, including:
- Your age,
- Your overall health,
- The stage, and grade of your cancer,
- Your response to the treatment(s) being used.
Ask your doctor which treatment(s), in his or her judgment, will give you the best life expectancy and quality of life. You may want to participate in a clinical trial, in which new and experimental therapies are tested in people with colon cancer.