Expert Health Articles

Colorectal Cancer Causes and Prevention

Douglas Yoder, MD

Surgical Associates of Northwest Ohio

The American Cancer Society estimates approximately 145,000 Americans will be diagnosed with colon or rectal cancer in 2019, and both men and women have an approximately 1 chance in 20 of being diagnosed with this cancer at some point in their lifetime. Statistically and depending on the year, it is either the second or third leading cause of cancer death among Americans. This disease has unnecessarily impacted and shortened many lives.  

Typical symptoms of colon cancer are not always easily identified and often onset gradually, so they are frequently missed or overlooked. Physicians often see patients who have no symptoms at all. Some patients simply feel tired or have shortness of breath easier than they would expect. Others may have blood in the stool, difficulty moving their bowels or a change in bowel habits. Pain in the abdomen, a mass in the abdomen or inability to move bowels at all are typically late signs.   

Many patients ask about the cause of colorectal cancer. Most colorectal cancer begins with a change in the lining of the large intestines into a polyp. Over time, the polyp can increase in size and the cells can change into cancer. That time frame is variable but typically takes years, not months or weeks to occur. Changes in genes lead to alterations in cells to enable polyps to form. These changes may be inherited from parents and tend to occur earlier in a patient's life.

African-Americans are at higher risk of colorectal cancer, as are individuals who have a first-degree relative with colon cancer (father, mother, brother, sister or child). A history of colon polyps or colon cancer, or a history of inflammatory bowel disease (ulcerative colitis or Crohn's disease) also increases the chances of colorectal cancer.

Most colorectal cancers, however, have no identified change in the genes and no family history of colorectal cancer. In contrast, factors that increase the risk for developing colon and rectal cancer include many choices that we make during our life. These choices also impact the chances of developing cancers in other areas of the body like the lungs or throat. Smoking and heavy alcohol intake increase the chances of developing lung cancer, head and neck cancer, and also colorectal cancer. Obesity, a diet that is high in the intake of red meat, and physical inactivity all come with higher risk of colon cancer.

Many people believe that if they do not have concerning symptoms and have no family history of colorectal cancer, it is impossible for them to get colon cancer. That is simply not true. It is recommended that everyone at the age of 50 should undergo colorectal cancer screening in some way. There are multiple techniques for screening and the discussion is warranted between you and your family physician about which option you should choose. The age that screening should start is under 50 for African-Americans as well as patients with a higher risk.

All individuals should all be aware of possible symptoms that could cause suspicion of a problem. Even if we are completely healthy, colorectal cancer screening should start for most of us at age 50, and for some, even earlier. The specific method of screening will be decided by you and your physician. Fortunately, the likelihood of Americans developing colorectal cancer has decreased over the years. This is felt to be due to improved screening methods. As with many cancers, prevention and early intervention can lead to better and longer lives.