Colon Cancer – What Is It?

Colorectal Cancer (also known as bowel cancer and colon cancer) is cancer found in the colon or rectum (part of large intestines).

Most colon cancers start as a growth on the inner lining of the colon called polyps. Over time, these polyps can change into cancer.

Factors which can increase chance of cancer include:

  1. If the polyp is larger then 1 cm
  2. If more than 2 polyps are found
  3. If the cells in the polyp show pre-cancerous changes called dysplasia
Watch a video on colon cancer

How does the colon look like?

The colon is around 5 feet long for undigested food to pass through before coming out as waste. The first section is called ascending colon, the second section is the transverse colon and the third section is the descending colon.

The last 2 sections are the sigmoid and rectum where the waste products sit and wait before being excreted. If you are constipated, the waste sits here longer.

How does Colon Cancer spread?

Over time a polyp can grow into the wall o the colon deeper into the layers of the wall and finally into blood vessels or lymph nodes. The final 4th stage is when cancer has spread to other parts of the body. The chance of surviving cancer gets LESS with each increasing stage.

What are the risk factors?

1) Age

  • Most colon cancers start after 50 years old

2) Diet

  • Long term consumption of red meat or processed meat
  • High-temperature cooking such as barbecuing and pan-frying
  • Low fibre intake (constipation increases time toxins in contact with the colon)
Image source: Verywell Health

3) Smoking

  • Smoking increases the risk of colon cancer and chance of dying from colon cancer

4) Family history

  • The increase in life time risk related to family history ranges from two to six fold
  • Risks are greatest in relatives of patients diagnosed young, tow or more affected relatives or relatives of patients with colon cancers

5) Obesity

  • Being overweight, having high fat diet and physical inactivity increases the risk of colon cancer

Why screen for colon cancer?

It is important to undergo screening for colon cancer because detecting colon cancer EARLY increases the chances of survival. Late stage cancers (such as stage 3 or 4) have a worse prognosis. In fact at the polyp stage, the removal of polyp eliminates the chance of it progressing to the later stage of cancer.

Image source: Newsweek

For those who have had polyps in the past should arrange for one or two yearly screening/surveillance. The screening of colon is by using a flexible endoscope called colonoscopy.

Screening is the testing of asymptomatic individuals to determine the risk of developing colon cancer and surveillance is the ongoing monitoring of individuals who have an increased risk for the development of the disease.

In conclusion, colon cancer is a major public health concern and is the 2nd most common cancer in Malaysia.

Screening lowers the incidence and mortality of colon cancer and colon cancer is preventable through the removal of premalignant polyps and is curable if detected and treated early.

Speak to our gastroenterologists and surgeons for more information!


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