The exact causes of colorectal cancer are not completely understood. However, many risk factors for colorectal cancer have been identified. While some of the risk factors are out of our control, a good number of them are avoidable if healthy lifestyle choices are pursued. The U.S. Preventive Services Task Force recommends that annual colorectal screenings start at age 50 and continue until age 75. After age 75, it should be an individual decision with one's doctor, taking into account overall health and potential cancer risk.
What follows is a list of some of the risk factors researchers have identified which cannot be controlled:
Gender. Men are at a greater risk for colorectal cancer than are women.
Age. The older you get, the greater your risk for colorectal cancer becomes. Individuals older than 50 years old should receive regular colorectal cancer screenings.
Prior Colorectal or Breast Cancer. Persons previously diagnosed with colorectal cancer have an increased risk for getting colorectal cancer again. Women who have previously had breast cancer are also at increased risk of colorectal cancer.
Genetic Background. Persons closely related to people who have had colorectal cancer are at increased risk themselves of getting colorectal cancer. African Americans have a greater general risk of getting colorectal cancer than do Caucasian Americans. There are two types of familial colon cancer, vulnerabilities for which are genetically inherited through one's parents: Familial Adenomatous Polyposis (FAP) and Hereditary Nonpolyposis Colorectal Cancer (HNPCC).
Presence of Polyps. Persons who have more polyps (especially larger polyps) are at an increased risk of colorectal cancer. Importantly, there are different types of polyps. Some types are more likely to become cancerous than others. Your doctor can let you know which type of polyp you have and what the correlated risk of cancer is for that polyp type.
Previous Bowel Disease. Bowel diseases such as Ulcerative Colitis, and Crohn's Disease, that cause the colon to become inflamed for long periods of time increase risk for colorectal cancer. Persons who have Ulcerative Colitis or Crohn's should get regular screenings for colorectal cancer.
Some of the risk factors for colorectal cancer are created by poor and unhealthy lifestyle choices. Making healthier lifestyle choices can result in a lowering of colorectal cancer risks.
Diet. Eating a diet high in fatty foods, especially those that come from animal sources (e.g., meat and dairy), can greatly increase risk for colorectal cancer. Diets that are low in fiber and low in fresh fruits and vegetables also appear to be associated with increased risk for colorectal cancer.
As the saying goes, "An apple a day keeps the doctor away". Eating a healthy and balanced diet reduces risk for colorectal cancer. Many Americans do not eat enough fresh fruits and vegetables or dietary fiber, while eating too much high fat meat. Eating five servings of fresh fruits and vegetables each day, while cutting down on meat intake will likely go a long way towards reducing dietary components of cancer risk. Dietary fiber can be obtained directly from fruits, vegetables, whole grains and beans and from dietary supplements including psyllium seed husks.
Sedentary Lifestyle. Sedentary people who don't get enough exercise run a much higher risk for getting colorectal cancer than people who lead an active lifestyle. Committing to a regular program of physical exercise is a great way to improve your overall health as well as reduce your risk for getting colorectal cancer. Cardiovascular exercises (including aerobics, jogging, biking, brisk walking, tennis and other court sports, etc.) which elevate your heart rate for extended periods of time are recommended.
Smoking. Smokers are up to 40% more likely than non-smokers to die of colorectal cancer. Given the terrible risks associated with smoking, it is in all smokers’ interests to quit smoking as soon as possible. Smoking is addictive and it is frequently difficult for smokers to quit. Repeated efforts at quitting may be necessary before a permanent tobacco-free state can be achieved. The effort is worth it in terms of improved health for the smoker and his or her family (who benefit from the absence of secondary smoke). Doctors, health professionals and employee assistance programs all offer programs designed to help smokers quit smoking.
Weight. While all people who are overweight are at an increased risk for colorectal cancer compared to people who are at recommended body weight, those who carry their weight in their belly are at especially high risk. Regular exercise, healthy eating choices, portion control, and support groups such as Weight Watchers can help to keep weight down.
Alcohol. People who use alcohol excessively have a higher incidence of colorectal cancer than those who do not.
In addition to changing your lifestyle to become healthier (as described above), there are a few other things that can be done to lower your chance of getting colorectal cancer:
Medicine. Some commonly prescribed and over-the-counter medications appear to be helpful in reducing colorectal cancer risk. Low doses of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) may help, as do estrogen-replacement therapies for older women. However, medicine should only be used under the guidance of a licensed medical practitioner.