Colon and Rectal Cancer

The pandemic has caused a significant impact not just on our medical, diagnostic and surgical needs, but also on the preventive components of our medical care such as immunizations, annual health assessments and screening measures which provide for early disease detection and appropriate medical or surgical treatments. It has been well recognized for decades that laboratory and radiological screening tests are very important − especially for older persons as well as those deemed to be at higher risk because of family history, past medical conditions or work environment. Examples include the PSA test for prostate cancer, chest X-rays for those at risk for lung conditions, breast screening mammograms for detection of early breast cancer, lipid blood levels for detection of high cholesterol and other lipids, and screening tests for those who are deemed to be at higher risk for cancerous tumours of the colon and rectum.

The Canadian Cancer Society reports that colorectal cancer is expected to be the fourth most commonly diagnosed cancer in Canada in 2022 (excluding non-melanoma skin cancers). It is the second leading cause of death from cancer in men and the third leading cause of death from cancer in women. By following recommended screening initiatives, the risk of fatal outcomes can be reduced by as much as 90 per cent.

As with many diseases, in seniors especially, prevention is improved by maintaining a healthy lifestyle. The World Cancer Research Fund International reports that there is strong evidence that certain lifestyle choices − such as being physically active, adopting healthy eating and drinking habits, not smoking and maintaining a healthy body weight − can decrease the risk of developing cancer.

All provinces in Canada have established provincial guidelines as to which individuals are deemed to be at higher risk, as well as when and how they should be tested to detect early stages of the disease. Although there are a few minor differences in some provinces, these guidelines generally provide you and your doctor with screening test recommendations. The reason for these important initiatives is that colorectal cancers are far more likely to be successfully treated when found early.

Anyone over the age of 50 and up to age 74 is considered at average risk; those who have a family history of colorectal cancer (parent, sibling or child) have an increased risk of developing the disease. Others at increased risk include those with a personal history of inflammatory bowel conditions or those with previous radiation treatment to the abdomen.

There are two main screening tests for colorectal cancer. Most provinces have now endorsed the FIT (fecal immunochemical test) as the screening test for persons of average risk. This test, which is free of charge, is available through your doctor or health agencies in your community. The test involves the collection of a small sampling of your stool and subsequent laboratory examination for a tiny amount of blood, which is often caused by colorectal cancer or precancerous polyps. Adenomatous polyps are benign growths in the rectum or colon which can turn into cancer in time and should be removed. Most provinces and cancer authorities recommend that this test be repeated every two years in this average risk population. Positive tests require immediate further investigation, which likely will mean a colonoscopy examination.

For the persons considered at increased risk for the development of such cancers, the screening protocols are more detailed. A colonoscopy should be performed starting at age 50, or 10 years earlier than the age at which their relative was diagnosed with colorectal cancer, whichever comes first. If the colonoscopy is negative, subsequent colonoscopies are recommended every five years for persons with a first-degree relative who was diagnosed with colorectal cancer before age 60, and every 10 years for those whose relatives were diagnosed at age 60 or older. Some provinces have minor variations to these guidelines.

Persons over the age of 74 do not greatly benefit from screening and generally, the risks of colonoscopy in this age group outweigh potential benefits. A less risky procedure in this age group −but not as accurate − is a special type of CAT scan.

A colonoscopy examination is usually done by a surgeon or gastroenterologist and involves a long flexible tube that is inserted into the rectum and extended further to the colon. A tiny video camera at the tip of the instrument allows the physician to examine the entire wall of the lower bowel in search of any abnormalities. Internal haemorrhoids, diverticulae, polyps or cancer may be detected. If polyps are found, they are usually removed during the colonoscopy and sent for pathological examination. The discovery of polyps, whether benign or showing malignant changes, will dictate subsequent timings for followup screening. The finding of bowel cancer would usually be followed by urgent surgical removal.

Symptoms and signs of bowel cancer may vary, but any changes in bowel habits should be promptly assessed. Blood in the stool − whether bright red or black − should be investigated immediately, even when the individual may have had some bleeding from haemorrhoids in the past. Periods of unexplained diarrhea or constipation, abdominal cramps, bloating or pain and weight loss may also be symptoms of bowel cancer. Urgent medical assessment is indicated.

The treatment of colorectal cancer involves urgent removal of the cancerous growth and a careful evaluation to determine whether or not the cancer has spread. In cases where the tumour is removed and no spread (metastases) is detected, the prognosis is good and should be followed by routine screening. In cases where there is spread, depending on where the spread has occurred, appropriate surgery, radiation or chemotherapy may follow.

Many Canadian family physicians will have a process in place in their offices to precipitate reminders for their patients regarding when immunizations, followup assessments, routine blood tests and recommended screening tests should be performed. Sadly, especially during the pandemic, this is not universally the case and, for one in four persons who doesn’t have a regular family doctor, such important preventive care is not followed. Such medical care has largely shifted to being our own responsibility and it is vitally important for us to ensure that these important procedures not be overlooked. Take charge of your health. You have a great opportunity to affect future health status for yourself and close family members by following recommended guidelines. Getting FIT has a whole new meaning!

by Robert MacMillan MD