What are the colorectal cancer risk factors, and what can you do to prevent them? As with many other cancers, there are elements of developing colorectal cancer that are still unknown, and there are yet other factors that are outside your control.
That said, you can take action to lower your risk, and it all starts with being informed.
What Is Colorectal Cancer?
Colorectal cancer refers to cancer that starts in the rectum or the colon. Depending on where it is, it might also be called colon cancer or rectal cancer. Most begin as a polyp (abnormal growth) in the inner lining of the colon or rectum that eventually changes into cancer.
There are different types of polyps that may develop in the colon or rectum. Hyperplastic and inflammatory polyps are more common and typically don't turn into cancer. Adenomas, on the other hand, are often precancerous; the majority (95 percent) of colorectal cancers are adenocarcinomas.
Polyps that meet one or more of the following risk factors have a greater risk of containing cancer:
- Being larger than one centimeter.
- Having abnormal-looking cells.
- Being seen with one or more other polyps.
If a polyp is cancerous, that cancer may eventually grow into the wall of the colon or rectum. The cancer's stage depends on how deeply it's grown into the wall and whether or not it's spread.
Risk Factors That Can't Be Changed
Colorectal cancer risk factors, as identified by the American Cancer Society, are grouped into two types: risks you can control and risks you can't. Risks you can't control include:
- Being older than 50.
- Having adenomatous polyps or colorectal cancer in your medical history or your family medical history.
- Being affected by an inflammatory bowel disease (IBD) such as Crohn's disease or ulcerative colitis.
If your IBD is untreated for many years, you're at a greater risk of developing abnormal cells that can turn into cancer. It's important to note that IBD is not the same as irritable bowel syndrome (IBS), which doesn't increase your risk.
As mentioned above, a family history of colorectal cancer or precancerous polyps can increase your risk, so if that applies to you, consider requesting genetic screening. The risk is the highest if your relative was diagnosed when younger than 45 or if more than one close relative had the cancer.
There are also several genetic syndromes that can lead to colorectal cancer, and some genetic components to be aware of:
- African Americans have the highest risk in the United States.
- Jewish people of Eastern European descent have the highest risk of any ethnic group in the world.
- Having type 2 diabetes can increase your risk.
Previous treatment for certain other cancers, such as testicular or prostate cancer, might also slightly increase your risk.
Preventing Colorectal Cancer
Although there are plenty of risk factors you can't control, there are still quite a few you can. The actions you can take starting today include:
- Changing your diet.
- Working out.
- Quitting smoking.
- Drinking less alcohol.
Simply being overweight — especially in terms of having a larger waistline — can put men and women at greater risk. Fortunately, small changes can have a big effect. Try integrating more whole grains, vegetables, and fruits into your diet. This is because consuming high amounts of red and processed meats can raise your risk, and so can cooking meat at very high temperatures using methods such as grilling, frying, or broiling. Note that fiber supplements don't really help, according to the American Cancer Society. For added protection, make an effort to keep your blood pressure and cholesterol under control.
Physical inactivity increases your risk, so try adding a daily workout to your regimen. Even a walk around the block is better than nothing!
Smoking isn't just linked to lung cancer, either; it can increase your risk of colorectal cancer. So can heavy alcohol use, which makes it wise to limit your consumption to two drinks per day for men and one drink per day for women. The CDC has also reported that low-dose aspirin can help prevent colorectal cancer in adults 40 and older, depending on other risk factors.
Last but not least, colorectal cancer screenings are the most effective way to reduce your risk and prevent colorectal cancer. These screenings can help doctors find precancerous polyps so they can be removed before they turn into cancer. Screenings can also locate cancerous polyps at an earlier stage, when treatment is more likely to be effective. The U.S. Preventive Services Task Force recommends that adults get regular colorectal screenings beginning at age 50. You may need screenings earlier if you have:
- Close relatives with polyps or colorectal cancer.
- A genetic syndrome that puts you at risk.
As you can see, there are quite a few colorectal risk factors that are under your control. A healthier diet, losing weight, and increased exercise can all reduce your risk of developing this cancer. If you have a family history of the disease, talk to your doctor about whether you should start getting screenings before the age of 50.