How does colon cancer develop? Doctor: This piece of extra flesh is the culprit

Intestinal cancer is not simply a cancer of the large intestine. It includes many intestinal systems, such as the rectum, colon, and anal canal. The incidence of colorectal cancer is extremely high in Western countries, almost ranking second or third in the incidence of cancer. In my country, the incidence of colorectal cancer has changed significantly over the years. Before the reform and opening up, the incidence was extremely low. After the reform and opening up, especially in modern times, the incidence has increased significantly. What exactly causes colorectal cancer?

95% of colorectal cancers are caused by colon polyps <br/>Clinical medicine has confirmed that 95% of colorectal cancers are caused by colon polyps. Colon polyps evolve into precancerous lesions in about 30 years, and into cancer in 5-10 years, and then infiltrate and metastasize. However, not all polyps will develop at the same pace as cancer. Polyps that are precancerous lesions and have a high chance of becoming cancerous include serrated adenomas, adenomatosis (including familial adenomatous polyposis and non-familial adenomatous polyposis), and dysplasia associated with inflammatory bowel disease.

Note:
Only a small number of polyps will not develop into colon cancer. Clinically, most polyps are adenomatous polyps, which will undergo malignant transformation.
Killing polyps starts with screening <br/>Once the cause is found, the progression of the disease can be well controlled. In other words, eliminating colon polyps can reduce the incidence of colorectal cancer. First of all, we must start with screening.

1. Screening of key populations
Screening age:
Start at age 50. The start time and interval of screening vary according to individual circumstances.
High-risk groups:
Positive fecal occult blood test; first-degree relative with a history of colorectal cancer; previous history of intestinal adenoma; personal history of cancer; changes in bowel habits; all people with colorectal alarm symptoms such as blood in the stool, black stool, anemia and weight loss; chronic diarrhea, chronic constipation, bloody stools with mucus, chronic appendicitis or history of appendectomy, chronic cholecystitis or history of cholecystectomy, long-term mental depression, etc.
General risk groups:
Those without symptoms of high-risk groups.

2. Screening plan ① For those without abnormalities, the screening interval is less than 10 years; if obvious symptoms or abnormalities occur during this period, timely examination must be carried out and the interval time must be adjusted.
② Those with a first-degree family history should start screening at the age of 40. If there are no abnormalities, screening should be conducted every 5 years. If abnormalities are found, screening should be conducted in a timely manner and regular reexaminations should be conducted according to the doctor's advice.
③ For those with a history of low-risk intestinal adenoma, colonoscopy should be repeated within 5-10 years after treatment. For those with a history of high-risk intestinal adenoma, colonoscopy should be repeated within 3 years after treatment. If no abnormalities are found in the first review, the follow-up interval can be extended to 5-10 years.
Low-risk adenomas include: 1-2 tubular adenomas found during a colonoscopy, and their diameters are less than 10 mm;
High-risk adenomas include: 3 or more adenomas found in one colonoscopy, or 1 adenoma with a diameter of 10 mm or more, or more than 1/3 of the adenomas have villous structures or high-grade intraepithelial neoplasia.
④ For patients who have undergone radical surgery for colon cancer, it is recommended to have a colonoscopy within 1 year after surgery, and then every 2-3 years; for patients who have undergone radical surgery for rectal cancer, it is recommended to have a colonoscopy every 3-6 months in the first 3 years, and then every 2-3 years.
⑤For female patients with endometrial cancer and ovarian cancer, it is recommended to undergo a colonoscopy every 5 years from the date of diagnosis.
⑥For patients with inflammatory bowel disease, it is recommended to start screening 8-10 years after the onset of symptoms.