Home > All Blogs > Causes of Colon Cancer


Causes of Colon Cancer

Colorectal cancer occurs in roughly 5 percent of people with a normal risk of having the disease.

There is no known risk of passing on genetic alterations that cause colon cancer from one generation to the next since the vast majority of cases (about 95%) are considered sporadic, which means the changes in DNA occur by chance after birth.

Approximately 5–10% of colorectal tumors are inherited, meaning they are caused by alterations or mutations in genes handed down through families.

Individuals with a family record of colon or rectal cancer but no known genetic disease-account for an additional 10% to 15% of all colorectal cancer diagnoses.

A person’s chance of acquiring colorectal cancer may be increased, however, by the following:


Early-onset cases of colorectal cancer are on the rise, although the vast majority of those diagnosed with the illness are still over 50.

Personal or family history

One’s risk of developing this kind of cancer increases if they have had polyps (abnormal growths) in their colon or rectum.

Polyps that are large, numerous, or composed of aberrant but noncancerous cells are particularly worrying (dysplasia).

Colorectal cancer runs in families, so that’s another factor.

One in three persons with colon or rectal cancer has a close relative who also has the illness.

Even if you were cured of colorectal cancer in the past, your risk of developing the disease again increases if you have had it before.

Type 2 diabetes 

People with this kind of non-insulin-dependent diabetes have a worse prognosis after being diagnosed and are at an increased risk of developing colon and rectal cancer

Inflammatory bowel disease (IBD)

Chronic inflammation of the large intestine is a possible complication of IBD, such as ulcerative colitis or Crohn’s disease.

The chance of developing colorectal cancer is raised as a result. You are not more likely to get colorectal cancer if you have IBS.

Adenomatous polyps (adenomas) 

While polyps themselves are not cancerous, some forms of polyps, known as adenomas, have been linked as precursor of colorectal cancer.

During a colonoscopy, in which the doctor peers into the colon using a lighted tube while the patient is under anesthesia, polyps are typically surgically removed.

Removing polyps from the colon reduces the risk of developing colorectal cancer.

Adenoma patients must frequently be screened for colorectal cancer and other polyps since they have a higher chance of developing these diseases.

Familial adenomatous polyposis (FAP), attenuated FAP (AFAP), and Gardner syndrome


These diseases are linked to the transmission of a faulty APC gene. When operating correctly, APC acts as a growth checkpoint for cells.

When mutated, it contributes to a chain of biochemical events that may cause hundreds of polyps in the colon to develop into cancer.

Lynch syndrome (hereditary non-polyposis colon cancer, or HNPCC) 


Many types of cancer, such as colorectal cancer, are more likely to develop in people with this hereditary cancer syndrome.

Usually, mutations occur in MLH1, MSH2, MSH6, PMS2, or EPCAM. DNA repair relies on these genes.

Once mutated, they lose their ability to protect against cancer-causing mutations.

Peutz–Jeghers syndrome


Most occurrences of this syndrome are caused by mutations in the STK11 gene (also called LKB1). Unaltered, the gene inhibits fast and unchecked cell division.

Colorectal polyps, which may develop into cancer if left unchecked, result from this unchecked proliferation.


Need help? Talk to Our Cancer Surgeon

Get the Most Effective Cancer Treatment in India by Consulting Dr. Nilesh Chordiya, One of the Top Cancer Surgeons in Mumbai.

Overweight or obesity

Weight problems, especially obesity, are associated with an increased chance of developing and passing away from colorectal cancer.

People who are overweight are more likely to get colon and rectal cancer, and the association seems to be greater in males than in women. Maintaining a healthy body weight may help reduce your risk.


In recent studies, eating a lot of red meat or processed meat has been linked to an increased risk of cancer.

Researchers have also looked at whether or not other dietary variables influence the risk of colorectal cancer.

However, there is less conclusive evidence that specific diets or foods increase or decrease that risk.


Long-time tobacco users risk developing and passing away from colorectal cancer more than non-users.

Although smoking is most often associated with lung cancer, it also increases the risk of many other types of malignancy

Alcohol use

There is a correlation between high or chronic alcohol use and an increased risk of colorectal cancer.

Alcohol has risks at any level of use, including moderate drinking. Stay away from booze if at all possible.

Men shouldn’t have more than two drinks daily, while women shouldn’t have more than one. The chance of developing some types of cancer may be reduced due to this.


Colorectal cancer is a consequence of damage to a cell’s DNA, resulting in genetic abnormalities called mutations.

Just a tiny fraction of colorectal cancer-causing mutations are inherited.

However, most are acquired, indicating they emerge later in life due to exposure to or choice of activities in the environment.


    About Author

    Dr. Nilesh is a renowned surgeon/ consultant practicing infinity media surge hospital, and Navkaar cancer clinic Mumbai and he is also visiting consultant at various hospitals in Mumbai, Thane, Dombivali, Kalyan, Navi Mumbai etc. With over 10+years of experience, he is highly trained and specialized in performing cancer surgery procedures from simplest to the most complicated surgeries.

    Related Blogs

    Stage One Colon Cancer Symptoms

    Stage One Colon Cancer Symptoms

    Colorectal cancer occurs in roughly 5 percent of people with a normal risk of having the disease. There is no known risk of passing on genetic alterations that cause colon cancer.

    read more