Tuesday 22 November 2022, 6:00 a.m.
How does colon cancer happen?
colon cancer It is a cancer that originates in the epithelium of the colon. According to the World Health Organization in 2020, colon cancer is the third most common cancer and the second leading cause of cancer death. Most develop from polyps in the colon. In which the first phase is a small polyp. But over time, when the polyp grows in size. Some of the polyps will start to become cancerous and spread further, as in Figure 1. The various symptoms of colon cancer, whether it is blood in the stool or constipation and diarrhea. It’s often found in cancers that are already large.
What are the benefits of colon cancer screening?
Colon cancer screening The aim is to be able to detect polyps in the colon before they become cancerous (Figure 2). It can be treated by cutting polyps through the gastrointestinal endoscopy. Colonoscopy and removal of colon polyps since they are not cancerous. It can prevent the occurrence of colon cancer.
Who should be screened for colon cancer?
Factors that can cause colon polyps include older age and family history of colon cancer patients. which if there are direct family members such as parents, siblings have a history of colon cancer It increases the risk of colon cancer in other family members.
When should I start screening?
For people without a family history of colon cancer It is recommended to start screening at the age of 45-50 years or more, even if there are no symptoms. It is recommended to be screened at age 40 or at age 10 before the age of patients diagnosed with colon cancer. for example If a family member is diagnosed with colon cancer at the age of 45, it is recommended that direct family members start screening at the age of 35, etc. If they meet the screening criteria, it is recommended to consult a doctor at the hospital for cancer screening. large intestine
How to screen for colon cancer
At present, there are two types of screening tests. The first is direct examination, namely colonoscopy. The doctor will insert a camera into the rectum and look at the entire colon. If colonic polyps are found can be cut out using the camera immediately or if a polyp is found that is suspected to be cancer A biopsy will be available for confirmation. This is the best method for detecting colon cancer. But there is a disadvantage. The patient must take a laxative to cleanse the colon before the colonoscopy. And during the endoscopy, complications may occur. If colonoscopy does not show any abnormalities It is recommended to repeat it every 10 years. Other less effective methods include CT colonography every 5 years, stool testing for latent blood. or a stool test for DNA The recommended method is a fecal occult blood test. It’s an easy and painless way to do it. It is recommended to check every 1 year, but if blood is detected in the stool need to be examined by colonoscopy further The other methods, such as enema into the anus. or a blood test for that cancer have a relatively low ability to detect Therefore, it is not recommended for colon cancer screening.
In summary, colorectal cancer It is a common cancer and a major cause of death. Colon cancer develops from colon polyps. Screening from the colon polyp stage is therefore important to prevent colon cancer progression.
Fig. 1 The progression to colon cancer.
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Fig. 2 Intestinal polyps (arrow, left) and colon cancer (arrow, right).
Lt. Col. (W) Ms. Thanyaporn Chantarojsiri
gastrointestinal disease work Internal Medicine Rajavithi Hospital
Royal College of Physicians of Thailand