Colorectal Cancer: Tests That May Save Your Life

Summer CSANews Issue 67  |  Posted date : Jul 22, 2008.Back to list

As I proceed with the unpleasant "preparation" for my colonoscopy exam this week, I am reminded of how important this cancer-screening test is and how many lives could be saved in Canada if those of us over the age of 50 took our doctor's advice about screening tests for this preventable cancer. My test, booked a year ago because of long waiting lists, was because of my strong family history of bowel cancer deaths, but screening tests are now recommended for all individuals between the ages of 50 and 75 because early detection saves lives.

Colorectal cancer is the second leading cause of death from cancer in Canada, following lung cancer. Just as lung cancer is largely preventable by not smoking, colorectal cancer is largely preventable through specific screening tests to detect early-treatable bowel abnormalities. Breast cancer in women and prostate cancer in men are the third most common cancers, but prevention initiatives are less effective in these diseases at this point in time. These bowel surveillance techniques have long been recognized by leading medical bodies, but only recently have gained prominence by physicians, medical organizations and governments.

Advances in Public Awareness
My first case as a family physician was a middle-aged man, a chef, who presented with rectal bleeding. In six months, he had succumbed to the disease. My 52-year-old sister presented with a significant change in bowel habits during a trip. Immediate attention to her problem upon her return to Canada led to her urgent surgery and the discovery that  She died 18 months later. The screening tests that we advocate today were not available then. Today, we can eliminate many of these tragic outcomes by following the screening guidelines advocated by the leading medical authorities. Even provincial governments are financially supporting the importance of this by rewarding physicians who are pursuing these preventive measures, as well as by advertising their importance to the public.

The recognized body in setting Canadian guidelines for this disease is the Canadian Task Force on Preventive Health Care, an independent scientific panel of experts in disease prevention, funded by the government. Their guidelines have been accepted and promulgated by leading medical bodies and governments in Canada. While screening tests are on the rise, there are still thousands of vulnerable citizens who are not being screened because of lack of knowledge, lack of recommendation by doctors for this group and lack of family physicians for growing numbers of Canadians. In Ontario, a government-sponsored "blitz" in the press and on TV has brought this to the attention of all during the last few months and incentive funding for many family health teams in the province is leading to higher compliance levels.

In spite of the overwhelming evidence that such screening tests can prevent most colorectal cancers, it is estimated that until recently, 80% of Canadians in the high-risk age category of 50-75 years of age have never had any type of colorectal cancer screening. To date, only Manitoba, Ontario and Alberta governments, along with their respective physician communities, have launched comprehensive screening approaches to address this serious public health deficiency. Public awareness campaigns, free distribution of cancer-detection test kits, increased funding for family physicians to be more actively involved and attempts to increase availability of colonoscopy resources are part of this strategy. Up until this recent splurge of enthusiasm, public health policy, as well as appropriate attention by primary-care physicians, has been inadequate.  When the Pap test was first introduced in the 1940s and proved beneficial in preventing cervical cancer, universal acceptance of its use took years to result. Perhaps the perception of the test's unpleasantness is the same phenomenon that is occurring with these tests proven to prevent bowel cancer.

These recent initiatives will hopefully increase the number of persons in this age group to get tested. Other provinces are developing strategies as well. Time is of the essence. It is estimated that 8,700 Canadians will die of bowel cancer this year. Programs to increase early detection of polyps and colorectal bowel cancer are extremely important in improving outcomes. A few countries have studied the unsolicited mailing of test kits to all of their citizens in this risk group, and have increased this surveillance to many more. Perhaps with Canada's shortage of family doctors, such a plan would accomplish more effective dissemination.

What should you be doing?
Between the ages of 50 and 75 years, you should be following these approved guidelines, even without any family history of the disease and no bowel symptoms. For those with no identifiable risk factor, you should have a simple test called an FOBT (fecal occult blood test) each time you have your periodic health exam which, for most of us, is yearly. This test, done at your own home and returned to the laboratory, is to detect loss of microscopic amounts of blood from the bowel, which often occurs as the earliest signal of pre-cancerous polyps or colorectal cancer.  As long as your risk for the disease is not related to family history or symptoms, this yearly test is all that most authorities recommend. In the U.S., certain authorities including the American Cancer Society recommend a more aggressive protocol for prevention tests, but the current evidence is not strong that this more advanced testing is warranted. Already, in most parts of Canada, the waiting times for the specialized investigations and treatments are becoming unacceptably long.

Precursors and Symptoms of Colon Cancer
The most common precursor of bowel cancer is a polyp, a fleshy round growth that grows in the inside lining of the large bowel (colon), more commonly in persons between the ages of 50 and 75. Since 75% of these polyps, called adenomas, are considered pre-cancerous, early detection and removal are extremely important. Most polyps, when detected by colonoscopy, can be entirely excised during the colonoscopy procedure and nothing further is required before a repeat colonoscopy in five years. Occasionally, a polyp is too large or is confirmed to already have become cancerous and a further abdominal surgical approach may be necessary to remove the growth.

If you have a direct relative who has had polyps or the disease, if your FOBT is positive, or if you have had any signs or symptoms of concern to your doctor, more specific examination will be recommended, including a scope of your lower bowel (flexible sigmoidoscopy) or, more likely, a full examination of your large bowel by means of colonoscopy. In these tests, a flexible instrument with a tiny camera is passed into the rectum and colon and slowly withdrawn, examining the entire surface for any abnormalities. The camera projects the image onto a screen which is read by the specialist, usually a gastroenterologist or a GI surgeon.

If you experience rectal blood, black stool, abdominal cramping, unexplained abdominal pain, constipation or diarrhea, you must check with your doctor immediately as these may signal colorectal cancer. The emphasis on prevention recognizes the importance of picking up on this disease before it becomes a cancer or, at least, in the very earlier stages wherein a cure is most likely.

A Final Word...
Today, we have much improved knowledge and better opportunities to affect our own health outcomes. Improving public health information and programs, increasing primary-care physician policies to effect greater distribution of testing kits and increasing timely availability of colonoscopy services are essential. But "in the end," it's up to you to ensure that you protect yourself from contracting this largely preventable disease. Be sure and ask your doctor or contact your local public health agency. Get tested!