Colorectal cancer prevention and screening

Common malignant tumors like colorectal cancer have been included in the national medical insurance. Colorectal cancer is the second most common cancer after gastric cancer and esophageal cancer, and it seriously threatens human life. The incidence of colorectal cancer in China varies among regions, with Shanghai, Zhejiang, and Fujian being high-incidence areas. Young people are the mainstream population in today's society. Due to the high work pressure, irregular diet and the development of fast food culture, more and more people are suffering from colorectal cancer. Therefore, prevention and screening of colorectal cancer are key.

How to prevent and screen for colorectal cancer?

First of all, how to screen for colorectal cancer?

1. Screening of the average risk population

According to data, more than 75% of Chinese rectal cancers are low-lying rectal cancers, which can be felt during a rectal digital examination. Therefore, when elderly people have physical examinations, a rectal digital examination should be included as a routine. If the patient has symptoms such as blood in the stool, changes in bowel habits, and deformed stools, a rectal digital examination should also be performed.

Many patients found that the fecal occult blood test was positive, but failed to conduct further examination in time, resulting in delayed diagnosis and missing the precious treatment opportunity. This should be a warning. The incidence of colon cancer and rectal cancer begins to rise significantly when people are 40-50 years old. About 75% of colorectal cancer occurs in these average risk groups. For these average risk groups, fecal occult blood tests should be performed every year starting at the age of 50 for 3 consecutive times. The cancer detection rate in asymptomatic positive people is above 1%. If any specimen is positive, a sigmoidoscopy and air-barium double contrast examination should be performed. In addition, a sigmoidoscopy can be performed every 5 years, or an air-barium contrast enema can be performed every 5-10 years, or a full colonoscopy can be performed every 10 years.

2. Screening of high-risk groups

Screening tests for people at high risk of colorectal cancer include:

1. If one of your parents, siblings or children has colorectal cancer, your risk of developing the disease increases and you should start standard screening with sigmoidoscopy, fecal occult blood or both at the age of 40.

2. Those who have undergone radical resection for colorectal cancer have an increased risk of recurrent cancer or new cancer. Carcinoembryonic antigen (CEA) should be dynamically monitored after surgery. If CEA continues to not decrease or decreases in a short period of time and then increases again, the possibility of incomplete resection or recurrence should be considered, and a colonoscopy should be performed in time to detect the presence of tumors. If a thorough examination is not performed before colorectal cancer resection, a colonoscopy is recommended within 1 year after surgery. If the current or preoperative colonoscopy shows normal results, the next colonoscopy can be performed 3 years later, and then every 5 years.

3. Familial adenomatous polyposis is caused by congenital or acquired defects in the adenomatous polyposis coli (apc) gene. Mutations in this gene often occur at the age of 20-30, which can lead to hundreds or thousands of adenomas in the colon. After the age of 40, almost 100% of people carrying this gene will develop cancer. For family members of this type, genetic counseling should be received and regular colonoscopy examinations should be performed from adolescence.

4. The canceration rate of adenomatous polyps is related to the size of the polyps. The larger the polyps, the more likely they are to become cancerous. If adenoma is found during the initial examination, electrosurgical biopsy is performed. If it is confirmed to be adenoma, a follow-up colonoscopy should be performed 3 years later. If the first follow-up examination shows normal results or a single small tubular adenoma is found, the next follow-up examination can be postponed to 5 years later; on the contrary, if the polyps are large in size and large in number, the interval between examinations should be shortened.

5. Hereditary non-polyposis colorectal cancer is an autosomal dominant hereditary disease in which multiple people in the same family suffer from colorectal cancer. Individuals suspected of having this disease should undergo a colonoscopy every 1-2 years starting at the age of 20-30, and once a year after the age of 40.

6. Patients with ulcerative colitis have an increased risk of colorectal cancer. This risk begins 8 years after the onset of the disease and continues to increase steadily. Patients with pancolitis should undergo a colonoscopy every 1-2 years, starting 8 years after the onset of the disease, and patients with left-sided colitis should undergo a colonoscopy every 1-2 years, starting 15 years after the onset of the disease.

7. In the past, it was believed that the polyps of patients with Peutz-Jeghers disease would not turn into cancer. However, in recent years, medical research has found that the probability of cancer in patients with Peutz-Jeghers disease is much higher than that of normal people. A survey showed that the incidence of malignant tumors in patients with Peutz-Jeghers disease is 20%-23%. Therefore, patients with Peutz-Jeghers disease should be actively followed up and examined and treated. For patients over 10 years old, a full digestive tract radiography should be performed every two years; for patients over 20 years old, a fiber colonoscopy should also be performed every two years.

8. For polyps larger than 1 cm, especially those with abdominal symptoms, endoscopic electrocautery, elective laparotomy, or laparoscopic resection of polyps or diseased intestinal segments with the assistance of fiber colonoscopy should be performed as much as possible; after the age of 25, a comprehensive examination including the abdomen and pelvis should be performed every year; female patients should also undergo breast examination, cervical smear and pelvic B-ultrasound examination.

Secondly, how to prevent colorectal cancer?

First of all, we should pay attention to developing good eating habits and lifestyles, limit the intake of saturated fatty acids, eat more foods rich in fiber, eat more fresh vegetables and fruits, especially yellow-green vegetables containing vitamins A and C. Do some sports that are suitable for you.

Secondly, pay attention to family history. If a person's immediate family members have colorectal cancer, the risk of colorectal cancer increases. People with a family history should undergo regular screening. Regular fecal occult blood tests, rectal digital examinations, and colon endoscopy screenings for high-risk groups are effective methods for early detection of colorectal cancer.

Third, we should prevent and treat precancerous lesions of the large intestine. For colon adenomatous polyps, especially familial multiple colon polyposis, the lesions must be removed as soon as possible. Patients with chronic ulcerative colitis have a high chance of developing colorectal cancer. If the condition changes, they should go to the hospital for examination at any time and actively receive treatment.

The above is an expert’s introduction to the prevention and screening of colorectal cancer. I hope it will be helpful to colorectal cancer patients. The key to colorectal cancer is prevention and screening. Doing a good job of prevention is the key to preventing colorectal cancer. I hope colorectal cancer patients can do the above.