Colon Cancer Screening and Prevention

Colon Cancer Screening and Prevention

Colon cancer is one of the most diagnosed cancers in Thailand. It is one of the top three leading cancers in both males and females. The lifetime risk of developing colon cancer is as high as 4 % in the Thai general population.

More than half of the patients with colon cancer are diagnosed at the later stages of the disease. The symptoms usually become obvious when tumors are larger in size. Those symptoms include changes in bowel habits such as alternating diarrhea and constipation or rectal bleeding. They may also lead to large-bowel obstruction, colon perforation, and severe rectal bleeding, attended by worse prognosis, increasing cancer-related deaths and higher medical expenses.

However, colon cancer is preventable. Before developing into cancer cells, abnormal cells start as small clump of non-cancerous cells (polyps). These cells are the result of abnormal colonic cell proliferation due to unregulated cell division and gene mutation. The development of polyps into cancerous tumors generally takes up to 10-20 years. Polyps are usually small and cause no symptoms. If they are removed before developing into cancerous tumors, colon cancer and complications can be prevented. Colon cancer screening is recommended to people with high risks.

Risk Factors

Risks factors of colon cancer can be categorized into 2 categories. Controllable risk factors include smoking, overweight, alcohol and excessive red meat intake. Uncontrollable risk factors are old age and family history of colon cancer. 10% of people older than 50 are diagnosed with colon polyps. Nevertheless, 80% of patients with colon cancer do not have family history of this cancer.

Prevention

It is recommended for people at average risk (no immediate family history of colon cancer) to have colon cancer screening starting at the age of 50 or above (in some countries, the screening may start at the age of 45.) even without any signs or symptoms because older age is one of the risk factors of colon cancer. The screening is to detect and remove polyps in the colon at the early stages to prevent later cancerous development. For those who have an immediate family member with colon cancer at young age, the screening should begin 10 years younger than the age when that family member was diagnosed with cancer.  For example: if your father was diagnosed with colon cancer at the age of 52, you should have the screening at 42.

Colon Cancer Screening

Standard colon cancer screening for those in good health without familial history of colon cancer includes fecal occult blood test (FOBT) every year or colonoscopy every 10 years at the recommended age mentioned. Fecal occult blood test is to check for the presence of blood in stool which is not visible to the naked eye. The unseen blood in stool can be a sign of polyps in the colonic wall; it may bleed when stools move through the colon. If blood in stool is detected, colonoscopy is necessary to diagnose colonic lesions. Colonoscopy can diagnose, detect, and remove polyps at the same sitting. If you have a normal colonoscopy, it needs not be repeated more often than every 10 years. If polyps are identified and removed, the next colonoscopy may be repeated earlier than 10 years based on the type, size, and quantity of the polyps.

In conclusion, colon cancer is a common cancer, often diagnosed when symptomatic at later stages of the disease. Colon cancer screening for people age of 50 or above by colonoscopy or fecal occult blood test for precancerous polyps is a highly necessary and important preventive measure to decrease cancer-related complications and deaths and minimize the cost of treatments.