Do you know what the risk factors and warning signs are for colorectal cancer (cancer of the lower bowel)? Here's some important information on risk factors – and on tests that can help screen for colorectal cancer.
- Age: As you age, your risk for colorectal cancer increases. In fact, more than 90% of those afflicted with the condition are over the age of 50, and the majority are 70 or older. This is partly due to the fact that colorectal cancer develops over a period of at least 10 years.
- Diet and lifestyle: A number of studies show that what you eat, as well as how physically active you are, may be linked to your likelihood of developing colorectal cancer. For instance, low-fat, high-fibre diets are associated with a reduced risk. Conversely, diets high in fat, calories, alcohol, and protein, and low in calcium may elevate the risk. Smoking also increases your risk of developing colorectal cancer.
- Family history: As with many other forms of cancer, the odds of getting colorectal cancer go up if a family member, particularly a parent or sibling, has had the disease. While this may be in part to genetic factors, it may also result from living in a similar environment or adopting a similar lifestyle. People with a family history of inherited breast cancer, uterine, or ovarian cancer are also at an increased risk for developing colorectal cancer.
- Polyps: Polyps are growths of tissue that can be found in the colon. These growths can be benign (non-cancerous) or they can go on to become cancerous. It has been shown that removing polyps that have been discovered by rectal exams and colonoscopies can reduce your chances of developing colorectal cancer.
- Inflammatory bowel disease: Ulcerative colitis and Crohn's disease have been associated with an increased risk of colorectal cancer.
When a person is diagnosed with colorectal cancer, that generally means they have malignant (cancerous) cells in the tissue of the colon and/or rectum. Doctors are able to make such a diagnosis by administering a variety of tests that analyze the rectum and rectal tissue as well as the blood. Catching colon cancer early with screening can greatly increase your survival. Common tests include:
- Fecal occult blood test (FOBT): A sample of a person's stool is placed on a card, which is then examined under a microscope to see if there is blood in the stool, a sign of colorectal cancer. Regular FOBT testing is recommended in people aged 50-74 years, since early detection can improve treatment and survival. There are several factors that can give a positive FOBT; therefore, a colonoscopy will usually be performed if you have a positive result.
- Digital rectal exam: A doctor or nurse examines the rectum with a lubricated, gloved finger to feel for any irregularities in the rectum or detect the presence of any polyps.
- Colonoscopy: A colonoscope (a thin, lighted tube) is inserted into the rectum to provide doctors with a comprehensive view of a person's entire colon and the rectum. The doctors can also take out tissues or polyps (growths of tissue) so that they can be analyzed for a more complete diagnosis.
- Biopsy: Cells or tissues are removed from the body for further examination under a microscope.
- Virtual colonoscopy: A series of X-rays, called computed tomography, are placed together to form a picture of the entire colon to search for any abnormalities. This test is also known as CT colonography.
- Sigmoidoscopy: A sigmoidoscope (a thin, lighted tube) is used to look inside a person's rectum and lower colon, also called the sigmoid. The sigmoidoscope checks for any abnormalities, including polyps and cancer.
- Barium enema: Barium liquid is injected into the rectum and the colon, allowing doctors to use X-ray technology to examine these areas for potentially cancerous cells or other issues.
Getting to the meat of the problem
Juicy steaks and other red-meat dishes are culinary signatures in many western nations, including Canada. However, our appetite for beef and other fatty foods may be one of the reasons colorectal cancer has become so common.
Researchers have found that red and processed meat may elevate the amount of compounds people have in their large bowel, which in turn mutates DNA, thereby boosting the risk of cancer.
In fact, one study found that people who ate a lot of red and processed meat – more than two portions a day – were much more likely to develop colorectal cancer than were people who ate less than one portion of these foods in a week.
On the other hand, fish and white meat, such as chicken breast, do not appear to increase the risk of colorectal cancer. Researchers examining people with a history of colon polyps found that those patients who ate a fair amount of chicken appeared to have a slightly lower risk for developing new polyps.
Other foods for thought
While different forms of meat seem to have differing contributions to colorectal cancer, most studies wouldn't point to meat in general to help lower the risk. The kinds of foods that have been tied to lowering the risk are fruits, vegetables, healthy fats (avocadoes, olive oil, nuts), and whole grains. Include plenty of water in your daily diet, as it helps with digestion and prevents constipation. Also, reducing consumption of foods high in sugar, thereby reducing blood sugar levels, has recently been found to decrease the risk of colorectal cancer.
Low-fat, high-fibre diets are also associated with a variety of other health benefits. So forget a bologna sandwich on white bread – instead, opt for a tasty low-fat cheese sandwich on whole wheat.
Screening saves lives
Make no mistake about it – screening saves lives. Whether it's the mammogram to screen for breast cancer or the fecal occult blood test (FOBT) for colorectal cancer, tests have the potential to detect abnormalities early – early enough that you can do something about it.
Studies show that regular screening with the FOBT – whereby samples of a person's stool are checked for blood – may reduce the mortality rate from colorectal cancer by anywhere from 15% to 25% in people aged 50 to 74 years.
Implementing a screening program
The success rate of screening has prompted provincial and federal government committees, as well as cancer advocacy groups, to encourage the implementation of an organized, province-wide colorectal screening program. In fact, some provinces such as Ontario and Manitoba already have such a program in place, and other provinces are in the process of implementing one.
The vision of such a program would be that eligible people between the ages of 50 and 74 would go for an FOBT at least once every 2 years. They would be contacted to ensure they get screened and a structured follow-up procedure would be in place.
The program is comprehensive, with a media campaign to inform the public, distribution of FOBT kits sent to those who are eligible, a designated central lab to analyze the FOBT specimens, and much more.
Such a program is notable not only for its potential to save lives, but also for being cost effective.
The various groups contributing to this initiative urge you to contact your provincial government representative to make this a reality if it's not already so where you live. Lives may be depending on it, so why not act now?
Finding time to be physically active is a challenge for most of us. Between the seemingly endless demands of work and family, it may seem like there just aren't enough hours in the day to squeeze in a brisk walk or a pick-up game of basketball.
But when it comes to the health of your colon and rectum and the rest of your body, you need to make time.
According to the Canadian Cancer Society, you can lower your risk of colorectal cancer by being physically active. Exercise helps you to maintain a healthy weight, which helps keep your risk of colon cancer down. Other possible reasons for the risk-lowering effect of exercise include effects on your metabolism, immune functions, and digestive system.
You don't have to run races or climb rock walls to cut your cancer risk. You can get started by taking brisk walks or taking the stairs instead the elevator. If you have joint pain, low-impact exercises like swimming are great options to keep your body fit and healthy.
So get moving and protect yourself!