colon cancer causes prognosis

Colon Cancer Causes and Prognosis

Colon, or colorectal, cancer is the third leading cause of cancer-related deaths in America. Colon cancer starts as small benign polyps in the colon. Later they suffer certain DNA changes and become cancerous. These cancerous cells grow and form tumors. They can also invade healthy tissue and spread to other organs.

There are different treatment options available for colon cancer. The most common include surgery, chemotherapy, and radiation.

As one of the most fatal cancers, you may be wondering about the causes and risk factors of colon cancer. What is the prognosis when it’s detected?

We’re going to discuss colon cancer causes and prognosis throughout this article.

colon cancer causes prognosis - blue cancer ribbon

What Causes Colon Cancer? Risk Factors to Consider

Although the exact cause of colon cancer is not known, there are several factors that may play a role.


Age is a major risk factor for colon cancer. It mostly affects older adults over the age of 50.


Your chances of developing colon cancer increase if your relatives have had it. Even if relatives have had intestinal adenomatous polyps will increase your risk.

Ulcerative Colitis or Crohn’s Disease

Individuals with ulcerative colitis or Crohn’s disease have a greater risk of colon cancer. This risk correlates with a person’s age when the disease occurs. It also depends on the amount of the colon or rectum it affects. The length of time a person has had ulcerative colitis and Crohn’s disease is a factor too.

Dietary Factors

Your diet plays a major role in your health and the development of diseases. Diets high in fat, animal protein, and refined sugars can lead to a greater risk of colon cancer. Make sure you have enough fiber in your diet too to avoid development.

Pollution and Toxins

Air and water pollution with various toxins and carcinogens are emerging risk factors. Be cautious of the chemicals you expose your body to as recent studies show they could lead to cancer.

Unhealthy Habits & Diabetes

Those with diabetes or who are obese also are at risk of developing colon cancer. Bad habits such as excessive alcohol consumption and smoking also factor into this risk.

Lynch Syndrome

Lynch syndrome, also known as hereditary nonpolyposis colorectal carcinoma, poses a risk. This inherited genetic variation causes 70-80% of people with it to develop colorectal cancer at a young age. It may also cause other forms of cancer that affect the small bowel, stomach, kidneys, ureters, and bile ducts.

MUTYH Polyposis Syndrome

MUTYH Polyposis Syndrome is a rare genetic condition. Over half of those with the genetic variation develop colorectal cancer. This often happens in the sixth decade of their life. Other forms of cancer may develop as well.

colon cancer causes prognosis - doctor talking to patient in hospital bed

What is the Prognosis of Colon Cancer?

Cancer is scary, but rest assured that many people survive colon cancer. According to the American Cancer Society, more than 1.5 million people survived in the US. The death rate has even decreased over the last decades. This is due to advanced screening methods followed by early diagnosis and treatment. Furthermore, different therapies are now available and colon cancer is easier to treat.

Doctors base the overall prognosis on several factors. It’s important to get treatment as early as possible if detected. Many people do not have symptoms in the early stages of colon cancer. When these symptoms appear, they depend on the size of the tumor and location along the colon.

Some symptoms of colon cancer include:

  • Diarrhea
  • Constipation
  • Persistent consistency changes in stool
  • Blood in the stool
  • Abdominal discomfort
  • Excessive gas
  • Fatigue

As the condition progresses, weight loss (without dieting) becomes more common.

colon cancer causes prognosis - polyp in intestine

Colon Cancer Stages

The stage and grade of colon cancer help doctors find the best treatment and evaluate the outcomes. The stage of cancer reflects the extent of cancer including how much and how far it spread to other organs.

Doctors use a TNM staging to determine the extent of cancer.

T stands for a primary tumor, which evaluates the characteristics of the tumor. These include the size and how much it has spread to other organs.

N stands for regional lymph nodes, and whether cancer spread to these lymph nodes or not.

M defines metastases, or the spread of cancer to different organs, like lungs or liver.

For each category, there is a number or letter assigned to describe the extent of cancer. The stages range from zero to four.

  • Stage 0 – The earliest stage with the most favorable prognosis and survival rate.
  • Stage 1 – The cancer is localized within the walls of the large intestine. The five-year survival rate for those treated is about 92%.
  • Stage 2 – The five-year survival rate is between 63% and 87% depending on the subtype.
  • Stage 3 – Cancerous cells spread to the lymph nodes and nearby organs. The survival rate is between 52% and 89%.
  • Stage 4 – Advanced cancer spread to distant organs and the survival rate at five years is 10% to 15%.

However, it’s important to use these numbers in context. You must assess other factors to better evaluate the prognosis.

Pathologists also classify colon cancer as low grade and high grade. They base this on how it appears under the microscope. Those who have low-grade cancer have a better prognosis.

You can find a Colon cancer survival calculator from MD Anderson Cancer Center. You need to fill in your age, gender, race, as well as the grade and stage of cancer. Keep in mind that this is an estimate used as a guideline.

In real life, there are people who can beat the odds and live longer than a calculator like this would predict. Focus on improving your overall health and make healthy lifestyle changes.