Colorectal cancer, or colon cancer, is common and has genetic causes. However, many environmental factors can dramatically increase or decrease a person’s chance of getting the cancer. Understanding how colon cancer develops and what lifestyle decisions associate with people who get it can make a big difference in reducing your risk.
People Over 50
Colon cancer is a multistep process that occurs in cells over time. The longer a cell lives, the higher it’s chance of getting mutations that convert it into a cancerous state. Thus, it makes sense that colon cancer normally occurs in people who are over the age of 50. In fact, 90% of people who have this cancer were above 50 when they found out. Colon cancer is considered a “disease of aging.”
A Family History of Polyps or of Colon Cancer
There is a strong genetic component to colon cancer, meaning you inherit your chances of getting this cancer from you parents. People who come from families in which many people have had polyps and/or colon cancer are more likely to get colon cancer than those who come from families that were never affected. The younger the age of family members when they get polyps or colon cancer, the higher the risk that other people in that ancestral line will also get colon cancer.
A Personal History of Cancer
Some people inherit a susceptibility to cancer in general, though their “colon cancer genes” are normal. Thus, if a person has had many types of cancers since an early age, they are more likely to develop colon cancer as they age.
Carriers of Genetic Mutations
Certain families have mutations in key genes that are known to cause colon cancer. A mutation in the HPNCC gene will result in colon cancer by the age of around 44. HPNCC mutations account for 2% of all colon cancers. A mutation in the APC gene will result in colon cancer by the age of around 40. APC mutations account for less than 1% of all colon cancers.
Cigarette smoking is associated with an increased risk of colon cancer. Though smoking introduces carcinogens into the lungs, which are located far from the colon, damaging particles can travel in the bloodstream to reach the colon. Furthermore, immune cells that flow in the blood through the lungs can be damaged by cigarette smoke and then travel to the colon where they malfunction and promote colon cancer.
People who eat diets that are high in fat and red meat have higher rates of colon cancer. Similar, diets that are low in fruits and vegetables are also associated with colon cancer. Diets that are high in fat and red meat can cause obesity, which is another risk factor for colon cancer. Fruits and vegetables protect against colon cancer because they contain phytochemicals that quench particles that damage cells in the colon. They also contain fiber, which makes food and toxins pass through the digestive system faster, meaning toxins have less time to interact with cells in the colon.