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The Risk Factors and Causes of Colorectal Cancer

Medically reviewed by John Paul Abrina, MD · Oncology · Davao Doctors Hospital

Written by Tracey Romero · Updated Feb 02, 2022

The Risk Factors and Causes of Colorectal Cancer

The digestive system enables the body to get all the vitamins and minerals it needs from the food we eat. Two important organs in the process of digestion are the colon and rectum, which make up the large intestine. Without the colon and the rectum, a person wouldn’t be able to get proper nutrition and rid themselves of bodily wastes. Just like the other organ systems, the colon and rectum are both susceptible to diseases like cancer. In fact, colorectal cancer is the third most common cancer in the world. In this article, we discuss the risk factors and causes of colorectal cancer. 

Causes of colorectal cancer

Colorectal cancer, also popularly referred to as colon cancer, is cancer that starts in the colon or the rectum. While both colon cancer and rectal cancer exist, they often are grouped together because of how closely related they are to one another. 

To understand the causes and risk factors of colorectal cancer, we need to talk about polyps. A polyp is a protruding growth of tissue located anywhere in the body, most commonly on tissues that wrap around organs or  openings. Colorectal cancer usually begins with polyps on the inner membrane of the colon or rectum. However, not all polyps can cause cancer. Typically, having more than two polyps that are larger than 1 cm and show signs of dysplasia increases the chances of them being or becoming malignant.

Cancerous polyps result from a rapid growth and accumulation of abnormal cells that have gene mutations. Although the exact causes of colorectal cancer is not yet known, scientists and experts agree that most cancers come from gene mutations in the cells located in a specific area of the body.

Not having specific causes for colorectal cancer doesn’t mean that you can’t completely avoid it. The first step to preventing this disease is to determine whether or not you’re more at risk of colorectal cancer. 

Risk factors of colon cancer

A risk factor is something that makes a person more at risk of developing a certain disease. Some risk factors, like age and family history, are unavoidable. But there are also risk factors, like certain behaviors and habits, which you can eliminate from your lifestyle. 


Colorectal cancer is more likely in people who are over 50 years old. In fact, 90 percent of the cases occur within this age group. However, there are reports of colorectal cancer occurring in people who are in their teen years.

Family history

Your risk of developing colorectal cancer greatly increases if it runs in your family. The risk is even greater if you have more than one relative who has received a diagnosis for colorectal cancer in the past. Cancers can be passed on from generation to generation in a family due to genetics.


African Americans have the highest mortality rate of colorectal cancer compared to other races. Hispanics also have been shown to have a higher-than-usual rate for colorectal cancer.

Medical history

Certain conditions or illnesses makes a person predisposed to colorectal cancer. Diseases that can put you at a greater risk of colorectal cancer include ulcerative colitis, Crohn’s disease, and cancer of the ovary, breast, or endometrium. People who have been treated with radiation therapy in the abdominal area are also at risk.

Lifestyle Factors

Lifestyle-related risk factors of colorectal cancer are those that are completely within your control. The following are some of the lifestyle habits and factors that may increase your risk of colorectal cancer:

Diet. Studies show that those who excessively consume processed and red meat are more at risk of colorectal cancer. high-fat and low-fiber diets can also put you at risk of colorectal cancer and other diseases.

Lack of exercise. Frequent exercise and physical activity can lower your risk of colorectal cancer and other diseases. 

Smoking and drinking. Tobacco and alcohol are risk factors of several cancers, including colorectal cancer. Cutting back on these substances can greatly decrease your risk of illnesses and will be good for your overall health and wellbeing.

Key takeaways

Colorectal cancer is characterized by the development of cancer cells in the large intestine. Learning more about the associated risk factors and causes of colorectal cancer can help guide you in making lifestyle changes that can decrease your chances of developing the disease. If you are at risk of developing colorectal cancer, consult your doctor. 

Learn more about Cancer here.


Hello Health Group does not provide medical advice, diagnosis or treatment.

Medically reviewed by

John Paul Abrina, MD

Oncology · Davao Doctors Hospital

Written by Tracey Romero · Updated Feb 02, 2022

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