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Rectal Cancer
Rectal Cancer- Saving lives with early detection
Cancer of the rectum is not as common as colon cancer, but about 45,000 new cases of rectal cancer are diagnosed annually. Approximately 7,300 people die of the disease each year. Still, death rates have fallen in recent years, possibly due to advances in detection and treatment methods.
Genetic factors play an important role in the development of the disease, but dietary habits are also thought to affect risk. Rectal cancer remains most prevalent in Western countries and among those who have adopted a Western-style, high-fat diet.
As with all types of cancer, early diagnosis is the key to successful treatment. Since the risk of rectal cancer increases sharply after age 40, screening tests are recommended for those in that age group. If cancer is found, surgery to remove cancerous tissue is the first line of treatment. Radiation therapy and chemotherapy are usually recommended as well. Prognosis depends on the stage and extent of the cancer at the time of diagnosis. If discovered early, recovery is likely.
Synonyms
- Adenocarcinoma of the rectum
- Carcinoma of the rectum
- Colorectal cancer (broad term used for both colon and rectal cancer)
- Colorectal malignancy (broad term used for both colon and rectal cancer)
Detailed Description
The lower portion of the digestive tract is called the large intestine. The rectum composes the last 6 to 10 inches of the large intestine, just before the anal opening.
In combination with colon cancer, it is the second leading type of cancer in the United States. Risk for rectal cancer begins to escalate after age 40, and it predominantly affects those over age 50. Family history and diet can play significant roles in the development of the disease. Evidence continues to mount that a low-fat, high-fiber diet rich in fruits, vegetables, whole grains, and legumes can significantly reduce your chance of developing rectal cancer.
As is true for any cancer, early detection is critical for successful treatment. Several screening tests are recommended for those at high risk, since screening increases the chance of discovering the disease while it is still in an early stage.
When a malignant tumor forms in the rectum, it may grow through the rectal wall and invade surrounding tissue. The cancer can also spread to other parts of the body, such as regional lymph nodes and vital organs. This process of spreading is called metastasis. When cancer is diagnosed, it is staged according to the level of its severity. Prognosis depends on the stage of the cancer at the time of diagnosis, and may also be affected by which treatment course is chosen. One staging system commonly used is as follows:
- Stage 0: Also called carcinoma in situ. Cancer localized on surface cells, or polyps.
- Stage I: Tumor invades the muscle layer of the rectum without spreading to the lymph nodes and without metastasis to distant sites.
- Stage II: Tumor penetrates all layers of rectal wall and moves further up the rectum without spreading to the lymph nodes or to distant sites.
- Stage III: Tumor spreads to regional lymph nodes but does not metastasize to distant sites.
- Stage IV: Tumor has invaded regional lymph nodes and metastasized to adjacent and distant tissues and organs.
How Common Is Rectal Cancer?
One in 20 Americans will develop colorectal (either colon or rectal) cancer at some point in their lives. While rectal cancer is less common than colon cancer, there are approximately 45,000 new cases diagnosed each year. The risk for developing rectal cancer begins to increase at the age of 40. About 90% of all cases occur in individuals over age 50, with 60 being the median age at diagnosis. The incidence of rectal cancer is slightly higher in males, while colon cancer is slightly more common in females.
What You Can Expect
Because rectal cancer can be present for several years before symptoms develop, early detection is critical to successful treatment. A five-year period without recurrence of the disease is considered a cure. Prognosis depends on the stage of cancer at the time of diagnosis:
- Stage 0: 95% cure rate
- Stage I: 90% cure rate
- Stage II: 65% to 75% cure rate
- Stage III: 35% to 65% cure rate, depending on extent of lymph-node involvement
- Stage IV: Median survival time is 18 months, but depends on the degree of metastasis and the cancer's growth rate
Established Causes
The specific cause of rectal cancer has not yet been determined.
Theoretical Causes
It is believed that both genetic and environmental factors such as diet play a role in the onset of the disease. A high-fat diet is thought to be a risk factor since carcinogens (cancer-causing agents) are produced during fat metabolism in the digestive tract. A low-fiber diet may also be causative: fiber helps to speed the passage of fats and other potential carcinogens through the body, so without adequate fiber these substances have more time to irritate the intestinal lining.
Risk Factors
The following factors may increase the risk of developing rectal cancer:
- Advanced age (90% of cases occur over age 50)
- Family history of colon or rectal cancer
- Personal or family history of polyposis
- Personal history of inflammatory bowel disease (either Crohn's disease or ulcerative colitis)
- Personal history of breast, ovarian, or uterine cancer
- High-fat, low-fiber diet
- Heavy alcohol consumption
- Sedentary lifestyle
Symptoms
Rectal cancer may have some of the following symptoms. Call your doctor if you have any of these warning signs:
- Bleeding from the rectum during a bowel movement
- Painful bowel movements
- Rectal discharge (pus or mucus)
- Persistent diarrhea and/or constipation
- Change in frequency of bowel movements or size and shape of stool, if such changes last more than a week or two
- Unexplained, persistent urge to have a bowel movement
- Straining to have a bowel movement without passing stool
- Feeling that bowels haven't been completely emptied, even after a bowel movement
- Pain while sitting
- Unexplained iron-deficiency anemia
Conditions That May Be Mistaken for Rectal Cancer
Other conditions with similar symptoms which may be mistaken for rectal cancer:
- Irritable bowel syndrome
- Inflammatory bowel disease (Crohn's disease or ulcerative colitis)
- Diverticulitis (small, inflamed pouches in the intestines)
- Hemorrhoids
- Anal or rectal fissures
- Other forms of cancer
How Rectal Cancer Is Diagnosed
Your doctor may use several tests to check for rectal cancer, among them:
- Physical examination: Your doctor will insert a gloved finger into your rectum to check for lumps.
- Laboratory tests: The fecal occult blood test can detect hidden blood in the stool. You will be asked to take stool samples at home and bring them into your doctor's office. To improve the test's accuracy, try to eat a high-fiber diet and no red meat for three days before you provide the samples. Your doctor may also run a test for carcinoembryonic antigen (levels of CEA, a protein in the blood, may be high when cancer is present).
- Imaging:
- Barium enema: This procedure allows your doctor to see the contours of the lining of your rectum and colon. You'll be given an enema that contains a white, chalky substance called barium to outline your colon and rectum, and then a machine takes X-rays of these areas.
- Endoscopy:
- Rigid Proctoscopy: You doctor may insert an inflexible, hollow instrument to inspect the rectum and lower portion of your colon. This method is often done along with a barium enema to provide a fuller picture, but proctoscopy is used less often than proctosigmoidoscopy.
- Proctosigmoidoscopy: As you lie on your side on an exam table, your doctor will insert a flexible fiber-optic tube with a tiny attached video camera (sigmoidoscope) into your rectum and the lower portion of your colon. The sigmoidoscope allows your doctor to view the walls of your rectum and colon on a video monitor. He or she will be watching for polyps, tumors, and other abnormal areas.
You may be asked to refrain from eating at midnight before the test, and you may have to have one or two enemas to clear your bowel for this test, which takes about five minutes to perform. If your doctor feels the need to check more of your colon, he or she may do a colonoscopy. - Colonoscopy: This procedure uses a fiber-optic endoscope (colonoscope) that has a longer reach than a sigmoidoscope. By gently inserting the colonoscope into your rectum and large intestine, your doctor will be able to check the entire length of the colon. During this procedure, your doctor can pass surgical instruments through the colonoscope to remove polyps or tissue (biopsy) to be studied under a microscope for cancer.
Your doctor will instruct you to prepare for colonoscopy with special dietary instructions. You'll also receive a laxative, enema, and maybe a sedative.
Staging rectal cancer
If you are diagnosed with rectal cancer, your doctor will determine the exact location and size of the tumor, as well as its other characteristics. For instance, transrectal ultrasound/sonogram uses high-frequency sound waves to assess how far the tumor has penetrated the rectal wall and surrounding tissue.
Your doctor will also run staging tests to try to check whether the cancer has spread to other parts of your body. For instance, a computed tomography scan (CT scan) can be used to detect tumors in the liver, pelvis, or lung.
Cancer that has not spread, but remains confined to the rectum, is much easier to cure than cancer that has spread to distant sites in the body. Staging the cancer is crucial, not only to assess your chances for recovery, but also to plan your treatment. For related news, products, and links to community, visit the Cancer Information eCenter.
Goals of Treatment
Rectal cancer is easiest to cure when it is found and treated in the early stages. Once it has spread to the to lymph nodes and other organs, cure may not be possible, but aggressive treatment can prolong life and ease symptoms.
Fortunately, effective treatments are available-- mainly a combination of surgery, radiation therapy, and chemotherapy. Your doctor and other medical experts will strive to destroy or reduce the number of cancer cells in your body, as well as lessen the chances of the cancer returning. Your healthcare providers will also help you to cope with the side effects of treatment. Even after treatment has ended, you'll still be seeing your doctor for several years so that he or she can monitor your overall health and check for any recurrences of cancer.
Treatment Overview
Surgery
Surgery is often used to remove rectal tumors. The type of surgery depends on various factors, such as how far the tumor lies from the anus and how much it has penetrated the layers of the rectum. When the cancer is a noninvasive one that's confined to the top layers of the rectum, a surgeon can cut it away without removing any section of the bowel.
If the tumor is in the upper part of the rectum, the surgeon may remove only that portion, leaving a rectal stump and the anus intact. Then the rectal stump is connected with the end of the colon. Once the tissues heal, you'll return to normal bowel function.
When the tumor is lower in the rectum and closer to the anus, the entire rectum, along with the anus, may need to be removed. That means that you'll need a permanent colostomy. In this procedure, your surgeon routes the healthy end of your large intestine to a surgically created opening in your abdominal wall. After a colostomy, your feces will empty into a bag, called a colostomy bag, that's worn outside the body, under the clothing.
During rectal surgery, surgeons usually remove nearby lymph nodes, too, to check for the spread of cancer.
Radiation
After surgery, radiation therapy may help control the growth of any cancer cells that remain. Radiation may also be used before surgery to shrink tumors.
Sometimes, radiation therapy is employed when surgery can't be performed because rectal cancer cells have spread into surrounding areas that the surgeon can't reach. In these cases, radiation can destroy the cancer, even in the inaccessible areas. When combined with chemotherapy under these circumstances, radiation therapy offers effective treatment and sometimes a cure.
In advanced cases, when rectal cancer has spread to other organs (metastasis), cure may not be possible, but radiation can still be used to slow the spread of cancer and to relieve pain.
Radiation can be delivered externally through X-ray beams, or it can be delivered internally by implanting radioactive materials in the body.
Chemotherapy
Chemotherapy can be used in many ways to treat rectal cancer.
After surgery, your doctor may prescribe chemotherapy to destroy any cancer cells that may have spread and to prevent cancer from returning.
If surgery isn't an option, a combined regimen of chemotherapy and radiation therapy may work well in treating and even curing rectal cancer.
In many cases, doctors will use all three therapies: surgery, radiation therapy, and chemotherapy. Chemotherapy drugs may be prescribed singly or in combination.
Drugs most commonly used
- 5-FU (Fluorouracil)
- Ergamisol (Levamisole)
- Leucovorin
Second choices
- Cisplatin
- Mitomycin
- Rheumatrex (Methotrexate)
New drugs in development
New drug treatments for cancer are being developed all the time. Ask your doctor about the latest therapies.
Appropriate Healthcare Settings
Treatment can take place on an inpatient or outpatient basis, depending on the level of care required. For instance, a proctosigmoidoscopy or colonoscopy can be done in the office of your doctor or gastroenterologist, or in the endoscopy suite of a hospital. In contrast, rectal cancer surgery is an inpatient procedure that requires a hospital stay.
Healthcare Professionals Who May Be Involved in Treatment
A number of health professionals work together to treat this condition:
- Family practitioners
- General internists
- Gastroenterologists
- Radiologists
- General surgeons
- Colorectal surgeons
- Surgical oncologists
- Pathologists
- Medical oncologists
- Radiation oncologists
- Nurse oncologists
- Enterostomal therapists
- Psychiatrists
- Dieticians
Activity & Diet Recommendations
If you've had abdominal surgery or a colostomy, you'll be eating only foods such as broth, apple juice, applesauce, and gelatin during the first week to reduce strain on your healing digestive tract. After a week, you'll be able to return to eating solid foods.
During cancer treatment, such as chemotherapy, eat several smaller meals throughout the day, and choose nutrient-rich foods. As you recover, you'll need adequate nutrition and sufficient calories to maintain strength, boost the immune system, and help the body heal. A registered dietitian can help you plan menus that go easy on your digestive tract.
Also, take care not to strain your abdominal muscles until your incision has healed. Lifting or bending down to pick up objects can cause you to pull your abdominal muscles. Once you feel up to it, walking and regular activity can help you to feel better. After you've healed, you'll be able to return to a normal routine of work and play, even if you've had a colostomy. Ask your doctor if you're concerned about any restrictions on your activity.
Monitoring Rectal Cancer
After you've been diagnosed and treated for rectal cancer, you'll need follow-up appointments with your doctor for several years to check your overall health and to monitor for any recurrences of cancer. The scheduling and nature of the visits may vary from person to person. But frequently, follow-up appointments for rectal cancer include these types of exams and screenings: physical exam, digital rectal exam, fecal occult blood test, carcinoembryonic antigen (CEA) test, chest X-rays, blood tests, and CT scans of the abdomen to check for metastasis.
Possible Complications
Treatment for rectal cancer may have the following complications and side effects:
Surgery:
- Wound infection
- Bleeding
- Impotence from damage to the sacral nerves during surgery
- Difficulty urinating
Radiation therapy:
- Impotence
- Vaginal dryness
- Nausea and vomiting
- Diarrhea
- Skin irritation
- Hair loss in pelvic area
- Lower blood count
- Fatigue
Chemotherapy:
- Nausea and vomiting
- Diarrhea
- Mucositis (inflammation of a mucous membrane)
- Hair loss
- Fatigue
- Lowered white blood cell counts, which increases the risk of infection
Quality of Life
If you receive a colostomy, nurses who are specially trained in colostomy care will counsel you on how to adapt to this major change. In time, you'll be able to resume an almost normal bowel routine and return to a full range of normal activities, including work, sex, and most sports. Here are some suggestions:
- Eat moderately and on a regular schedule.
- Eat a healthy diet, avoiding fried foods and refined, low-fiber foods. You may want to ask your colostomy advisor for a list of gas- or odor-producing foods to avoid.
- Use a specially formulated colostomy-pouch deodorant to control odor.
- Don't wear belts or waistbands directly over the stoma.
- Avoid rough contact sports and those placing strain on the abdominal muscles.
- Empty the ostomy pouch before swimming or any sexual activity.
Joining an ostomy support group can be helpful. Contact the American Cancer Society for more information.
Considerations for Women
If rectal cancer spreads, the bladder and vagina are common target sites because they lie nearby in the pelvis. Talk to your doctor about prevention and early detection.
Pregnancy
Chemotherapy and radiation treatments are not options during pregnancy.
Nursing mothers
Avoid nursing during chemotherapy because your baby may swallow chemicals through your breast milk. Wean your baby onto formula before you begin chemotherapy.
Preventing Rectal Cancer
Lowering your fat intake and increasing fiber are the two critical dietary components in reducing your risk of rectal cancer.
Major sources of fat are meat, eggs, dairy products, salad dressings, and cooking oils. The products of fat metabolism can lead to the formation of cancer-causing chemicals, or carcinogens. A diet high in vegetables and high-fiber foods such as whole-grain breads and cereals may rid the bowel of these carcinogens and help reduce the risk of cancer.
Fiber, or roughage, is the insoluble, nondigestible part of plant material present in fruits, vegetables, and whole-grain breads and cereals. A high-fiber diet leads to the creation of bulky stools that can help speed potential carcinogens through the intestines, allowing less time for them to react with the intestinal lining.
The National Cancer Institute's dietary guidelines recommend a minimum of five servings of fruits and vegetables each day for cancer prevention. Other nutrition guidelines include eating six to 11 servings of breads, grains and cereals per day. A plant-based diet is usually low in saturated fats, high in fiber, and a good source of phytochemicals (natural substances found in fruits and vegetables that seem to offer some protection against the formation of certain tumors).
Early detection
Early detection of rectal cancer is the next best thing to prevention. Screening tests can help to catch colorectal cancer while it is still in an early stage and increase the chances of effective treatment. Recommended screening tests include:
- Annual fecal test for blood in the stool, starting at age 50 (limited accuracy).
- Annual digital rectal examination, starting at age 50.
- Sigmoidoscopy every five years, starting at age 50.
- Colonoscopy every 10 years, starting at age 50 (more frequently for people with certain risk factors); or double-contrast barium enema every 5-10 years, starting at age 50.
People with a family history of colorectal cancer (in which a first-degree relative had the disease before age 60, or two first-degree relatives had the disease at any age) may need to start screening at age 40 or earlier. Also, people with chronic inflammatory bowel diseases or a personal history of colorectal cancer or polyps may need earlier and more frequent screening.
Young people with a family history of familial adenomatous polyposis or hereditary nonpolyposis colon cancer are at high risk for colon cancer and may need to have colonoscopy and other tests as early as puberty or age 21.
Self-Care Measures
- Try to reduce stressful factors in your environment, which can affect your immune system's ability to fight off disease.
- Dietary factors can play an important role in cancer treatment. Adequate nutrition is needed to maintain strength, boost the immune system, and help the body heal after surgery and other therapies.
- Exercise can enhance physical and emotional well-being for people with rectal cancer. It can help to control weight, increase energy, and maintain range of motion. It may also help to boost your mood, minimizing depression and anxiety. Talk to your doctor about creating an exercise program that is suited to your overall state of health.
Websites & Organizations
American Cancer Society
625 North Court
Palatine, IL 60067
Phone: 800-ACS-2345 (227-2345)
American Digestive Health Foundationsm
7910 Woodmont Avenue, 7th Floor
Bethesda, MD 20814-3015
Phone: 301-654-2635 or 301-654-1140
Email: dlee@gastro.org
American Society of Colon and Rectal Surgeons
85 W. Algonquin Road, Suite 550
Arlington Heights, IL 60005
Phone: 847-290-9184
Fax: 847-290-9203
Cancer AnswerLine
800-865-1125
Cancer Care Inc.
Cancer Information Clearinghouse
National Cancer Institute
1275 New York Ave., Box 166
New York, NY 10021
Phone: 800-4-CANCER (422-6237)
Comprehensive Cancer Center University of Michigan
1500 E. Medical Center Dr.
Ann Arbor, MI 48109
Cancer Information Line: 800-865-1125
Email: wwwcancer@umich.edu
National Coalition for Cancer Survivorship
1010 Wayne Avenue, 5th Floor
Silver Springs, MD 20910
Phone: 888-837-6227 or 301-650-8868
United Ostomy Association
36 Executive Park, Suite 120
Irvine, CA 92714
Phone: 714-660-8624
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