Cancer

Colorectal cancer

What is colorectal cancer?

The body's basic unit—the cell—has a life cycle during which it grows, divides, and dies. Cells divide to produce more cells only when additional cells are needed by the body. This orderly life cycle is what keeps the body healthy. During childhood and adolescence, normal cells divide more rapidly until a person reaches adulthood. After that, cells in most parts of the body divide only to replace old or dying cells and to repair injured organs or tissues. However, cancer occurs when abnormal cells divide without control or order. Rather than dying, cancer cells outlive normal cells and continue to produce new, abnormal cells.

Cancer cells develop as a result of damage to deoxyribonucleic acid, or DNA. Present in every cell of the body, DNA directs the activities of the cell. In most cases, when DNA becomes damaged, the body is able to repair it. In cancer cells, however, damaged DNA is not repaired. The cell takes on an abnormal life cycle and continues to grow and divide in an out-of-control fashion. Cells continue to divide when new cells are not needed, resulting in a mass of extra tissue. Such masses—known as tumors—may be benign or malignant.

Colorectal cancer, as the name implies, affects two parts of the lower intestine: the colon (also known as the large intestine) and the rectum. Cells lining the colon and rectum begin to grow out of control. In addition to affecting the colon and rectum, colorectal cancer also includes cancers of the appendix and some anal cancers.

Benign tumors are not cancer. Non life-threatening, these can be removed, and generally, they do not recur. Cells from benign growths do not metastasize (spread) to other parts of the body. Nearly all cases of colorectal cancer begin with the development of benign colorectal polyps—growths that form when the cells lining the colon and rectum begin to follow an abnormal life cycle, growing, dividing, and reproducing in an abnormal fashion.

Not all polyps develop into colorectal cancer, but most colorectal cancers begin as polyps. If the cells of a polyp metastasize (spread) to other parts of the body, a malignant (cancerous) tumor develops.

What are the risk factors for colorectal cancer?

Some people are more prone than others to colorectal cancer. A risk factor is anything that increases your risk of developing a particular disease. There are several risk factors that can increase your chance of developing colorectal cancer. If you believe you're at greater risk of developing colorectal cancer, talk to your doctor. He or she can recommend ways for you to reduce your risk. Together, you can develop a schedule and plan for regular colorectal cancer screening.

Age

As with many other cancers, colorectal cancer primarily affects the elderly: nearly half of all people diagnosed with colorectal cancer are over the age of 70. Adults over the age of 50 are considered at average risk for colorectal cancer. An individual's risk of developing colorectal cancer begins to increase after age 40. This, however, does not mean that people under 40 are immune to colorectal cancer.

Family history

If a close relative has had colorectal cancer, your risk of developing the disease increases. Risk is even greater if more than one relative has had colorectal cancer or if a relative developed the disease before the age of 50. Anyone with relatives who have had other cancers such as breast, cervical or uterine cancer is at increased risk of developing colorectal cancer.

Personal history of polyps, bowel disease, or colorectal cancer

If you've ever had polyps or growth in your intestinal (bowel) wall, you're at greater risk of developing colorectal cancer. Because nearly all cases of colorectal cancer begin with the development of benign colorectal polyps, the prevention of colorectal cancer depends on the detection and removal of polyps.

Anyone with a history of inflammatory bowel diseases (colitis or Crohn's Disease, for instance), is at higher risk of developing colorectal cancer. If you've had colorectal cancer in the past, you're at higher risk of developing malignant tumors of the colon or rectum.

Hereditary factors

Although rare, there are inherited conditions such as familial adenomatous polyposis (FAP) or hereditary non-polyosis colon cancer (HNPCC) in which large numbers of polyps develop in the colon and rectum. If you have an inherited genetic syndrome such as these, you're at greater risk of colorectal cancer.

Sedentary lifestyle

Lack of regular excerise has been found to contribute to the development of colorectal cancer, particularly when a sedentary lifestyle is combined with a high-fat diet.

Be sure to include physical activity into every day. There is evidence that regular exercise can help protect against cancer in general, including colorectal cancer. An active lifestyle, when combined with a healthy diet (see below), appears to help guard against colorectal cancer.

Diet

There is evidence that a diet rich in fruits and vegetables may help reduce the risk of colorectal and other cancers. Be sure to eat a healthy, balanced diet high in fruits and vegetables. For information about good nutrition and healthy eating, see Nutrition.

Screening for colorectal cancer

As with many other cancers, colorectal cancer responds best to treatment when detected early. Treatment of colorectal cancer is most effective before the cancer has metastasized outside the colon.

When there are no symptoms present, screening for colorectal cancer should be part of routine medical care. Talk with your doctor or healthcare professional about screening for colorectal cancer. Screening tests include:

Digital rectal exam

As part of your annual physical (if you are over 40), your doctor inserts a lubricated, gloved finger into your rectum and feels for any abnormalities.

Fecal occult blood test (FOBT)

Designed to test for hidden (occult) blood in the stool, a symptom of colorectal cancer or of some other problem, a fecal occult blood test requires that you collect stool samples over three days in the privacy of your home. These samples then undergo chemical tests to check for the presence of blood. If blood is found, your doctor will request additional tests in order to make an accurate diagnosis.

Flexible sigmoidoscopy

Designed to check for polyps, tumors, or other abnormalities in the rectum or lower large intestine, this test involves the slow and gentle insertion into the rectum of a tube equipped with a light.

Air contrast barium enema (combined with flexible signmoidoscopy)

A special x-ray of the bowel, this test involves the insertion of a special dye—called barium—into the colon. The barium forms an outline on the wall of the bowel, allowing a radiologist to examine the entire colon without the need for a scope. Before having this x-ray, you'll be required to take a laxative.

Colonoscopy

In a colonoscopy, a hollow, flexible video or fibre-optic tube is gently inserted into the rectum, allowing an endoscopist to see the entire colon. To prepare for a colonoscopy, you will be required to take a laxative. You may be given a sedative during the procedure.

Pathology tests

Flexible sigmoidoscopy and colonoscopy allow your doctor to remove tissue samples and polyps which are then sent to a pathologist for examination under a microscope. The pathologist will examine these tissues to determine whether cancer is present.

What are the symptoms of colorectal cancer?

Generally, colorectal cancer does not show signs or symptoms in the early stages. Symptoms begin as the tumor beings to affect colorectal structures—whether by constriction, obstruction, or ulceration. Be sure to see your doctor immediately if you experience any of the following:

Either very bright red or dark blood in the stool Diarrhea, constipation, or both—lasting more than a few days Frequent gas pains Constant fatigue Unexplained anemia Strong and continuing needs to move bowels, but with little or no stool

Frequent or constant cramps, lasting for more than a few days General stomach discomfort such as cramps, bloating, or fullness Stools that are narrower than usual Unexplained weight loss A feeling that the bowel doesn't completely empty

Although these symptoms can signal other problems such as an inflamed colon, ulcers, or hemorroids, only your doctor can make an accurate diagnosis. When colorectal cancer is found early and treated before it has had an opportunity to spread, it is often curable.

How is colorectal cancer treated?

After you tell your doctor about your symptoms, he or she may recommend any of the following tests (see above):

Digital rectal exam Fecal occult blood test Flexible sigmoidoscopy

Air contrast barium enema Colonscopy Pathology of tissue samples

Treatment of colorectal cancer is most effective when the cancer is found early. Treatment may involve surgery, chemotherapy, or radiation therapy.

For more information on colorectal cancer, contact:
the Canadian Cancer Society toll-free at 1-888-939-3333 or
the National Cancer Institute toll-free at 1-800-422-6237.

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Colorectal cancer screening saves lives

Most States Fail to Require Insurance Coverage of Preventive Tests

(ARA) - Colorectal cancer is one of the most preventable forms of cancer. The disease generally develops in the colon over five to 10 years as growths, or polyps, become cancerous. Colonoscopy, currently the most effective method for colorectal cancer screening, allows doctors to detect and remove polyps. It is estimated that the United States could save $191 million dollars in medical costs annually if Americans underwent colon cancer screening as recommended.

Unfortunately, research shows that significant barriers such as a lack of insurance coverage deter Americans from being screened for colorectal cancer. Approximately 41 million Americans who should be tested for colorectal cancer have not yet undergone screening. Available preventive tests make colorectal cancer highly preventable and treatable, yet the disease remains the second leading cancer killer.

Concern about how to pay for colorectal cancer screening shouldn't stand in the way of saving a life—but unfortunately it can. "We believe that colorectal cancer screening merits a higher priority on our nation's public health agenda," said Bernard Levin, M.D., chair of the American Gastroenterological Association's Public Affairs and Advocacy Committee. "Persuading more states to pass preventive screening legislation has the potential to save thousands of lives and billions of dollars spent annually to treat advanced colorectal cancer."

Insurance barriers to colorectal cancer screening have and continue to be tackled in state legislatures across the country. According to a new report, 17 states and the District of Columbia have passed legislation requiring insurance to pay for colorectal cancer screening. However, far more states have laws that guarantee coverage of preventive tests for cancers with lower death rates. Guaranteed insurance coverage laws exist in 47 states for breast cancer, 26 states for prostate cancer, and 23 states for cervical cancer, despite the fact that each type of cancer claims fewer lives annually than colorectal cancer.

The 2005 Colorectal Cancer Legislation Report Card gave passing grades to California, Connecticut, Delaware, Georgia, Illinois, Indiana, Maryland, Missouri, Nevada, New Jersey, North Carolina, Rhode Island, Tennessee, Texas, the District of Columbia, Virginia, West Virginia and Wyoming. Consumers who live in the 33 states that received failing grades (D-F) can go to the Report Card Web site at www.eif.nccra.org to obtain insurance resources and to contact their state legislators.

The National Colorectal Cancer Research Alliance, co-founded by journalist Katie Couric and the Entertainment Industry Foundation, and American Gastroenterological Association developed the Report Card in collaboration with leading medical societies and patient advocacy groups, including the American College of Gastroenterology, American Society for Gastrointestinal Endoscopy, American Society of Colon and Rectal Surgeons, Cancer Research and Prevention Foundation, Colon Cancer Alliance, Hadassah and STOP Colon/Rectal Cancer Foundation.

For more information on colorectal cancer, please visit www.eif.nccra.org.

Courtesy ARA Content