Causes of Colon Cancer

While all of the causes of colon cancer are not fully understood, there are several things that are known about this disease, what causes and what puts an individual at an increased risk of developing it.

Like any cancer, colon cancer is a malignant tumor. Generaly, cancers arise when cells in the body suffer damage to their genetic material (DNA), called mutations. If just the right mutations occur in one cell, it can begin to grow and divide in an uncontrollable manner, leading to a tumor. See the What Causes Cancer? page for more info.

Therefore, colon cancer, like all other types of cancer, develops when mutations occur in the cells lining the inside of the colon. These mutations can be caused by many things including carcinogenic chemicals or physical factors. Everyone is exposed to potentially cancer-causing chemicals which get into our system. However, some things, including lifestyle choices, family history and other, can increase that exposure and the risk that mutations will occur.

Some of these causes of colon cancer that increase the risk of cancer developing in the intestines are reflected in risk factors for the disease. These are factors that make the likelihood of this cancer developing in an individual greater.

Causes of Colon Cancer: Risk Factors

Family History: While most colon cancer develops in people who do not have a family history of colon cancer, some cancers may be related to genetics and family history. This is particularly true if multiple people in your family have suffered from colon cancer and if colon cancer presented at a younger age in family members. Additionally, there are some rare familial disorders that are highly associated with increased risk for colon cancer, such as familial polyposis.

Colon Polyps: Most colon cancer develops first from a benign tumor that can grow on the inside of the colon called a colonic polyp. These are small growths of abnormal cells and are shaped like a mushroom. While the polyp is itself benign, the cells in the polyp can go on to develop into cancer. Therefore, a person with a history of colon polyps (which can be seen on colonoscopy) is at increased risk of later developing colon cancer.

Diet: Another colon cancer cause and risk factor is a diet high in fat and cholesterol. The breakdown of fat may lead to the formation of carcinogenic chemicals. On the other hand, a diet high in vegetables and fiber help to rid the colon of these toxic chemicals and probably reduce the risk of developing cancer somewhat.

Inflammatory Bowel Disease: Inflammatory diseases of the bowel, such as Ulcerative Colitis and Crohn's Disease, lead to chronic inflammation and injury to the wall of the intestine. In the large intestine this chronic injury increase the risk for development of colon cancer. While this is not one of the common causes of colon cancer in the general public, it is certainly important in those individuals with a history of these diseases.

Others: There are other factors which may influence your risk for colon cancer. For example, alcohol, a history of diabetes, environmental factors, and smoking have all shown links to colon cancer in various studies, although there is some controversy about how much some of these affect the overall risk for cancer.