Overview
The colon (large intestine) is a tube-shaped organ about 1.5 meters long in the digestive system, responsible for absorbing water from stool. Colon cancer usually begins as benign polyps in the colon lining that become malignant over time. Adopting a healthy lifestyle can help reduce the risk.
- According to GLOBOCAN 2020, Vietnam recorded nearly 16,000 new cases and more than 8,200 deaths. It is common in people over 50 but is rising rapidly among younger people. It is the 5th most common cancer in Vietnam. Colon cancer is usually grouped with rectal cancer (together called colorectal cancer).
Risk factors
- Age: Risk increases with age, especially over 50.
- History of colorectal polyps (especially adenomas) or previous colorectal cancer.
- Inflammatory bowel disease (IBD) such as ulcerative colitis or Crohn’s disease.
- Family history of colorectal cancer in first-degree relatives, especially at a young age.
- Genetic syndromes: Familial adenomatous polyposis (FAP) and Lynch syndrome.
- Obesity and overweight from an unhealthy diet and inactivity.
- Smoking and exposure to tobacco smoke.
- Type 2 diabetes and insulin resistance.
- Excessive alcohol use.
- A diet high in red and processed meat (salted, fermented, smoked).
- Prior abdominal radiation for cancer treatment.
Stages of colon cancer
Colon cancer usually causes no obvious symptoms in its early stages, so it is hard to detect without regular screening. It has 5 stages:
Stage 0: Cancer in situ — cancer cells are only in the mucosa (inner lining) of the colon or rectum.
Stage I: Cancer has invaded through the mucosa into the muscle layer, without reaching nearby tissue or lymph nodes.
Stage II: Cancer has grown through the wall of the colon or rectum to the visceral peritoneum and nearby structures, without spreading to lymph nodes or other organs.
Stage III: Cancer has spread to nearby lymph nodes but not to distant organs.
Stage IV: Cancer has spread to distant organs.
Colon cancer screening
The fecal immunochemical test (FIT) is used to screen for colon cancer. Intestinal polyps and colon cancer cells often have fragile blood vessels that bleed easily during digestion; FIT detects this hidden blood — an early sign of precancerous or cancerous cells. Advantages: high sensitivity, fewer false positives, no dietary restrictions before sampling, and it can be done at home on a random stool sample. At NURA, a high-quality FIT kit (developed in Japan) requires only a very small stool sample and gives accurate results in about 5 minutes.