National Cancer Prevention Awareness Week | 5 methods of colorectal cancer screening you must master

April 15 to 21, 2022 is the 28th National Cancer Prevention Awareness Week. The theme of this year’s awareness week is “Early Action for Cancer Prevention and Control”, which aims to actively advocate everyone Be the first responsible person for your own health, correctly understand cancer, actively prevent and control cancer, establish the concept of tertiary cancer prevention, practice a healthy and civilized lifestyle, take the initiative to participate in cancer prevention health examinations, and achieve early prevention, early detection, and early diagnosis , early treatment, reduce cancer morbidity and mortality, improve cancer early diagnosis rate and survival rate, effectively curb the harm of cancer, and improve the health of the people.

Colorectal cancer is one of the most common malignant tumors in the world, and it is also one of the most common malignant tumors in my country. In 2020, in my country, the incidence of colorectal cancer jumped to the second place, and the number of new cases reached 550,000. Its death toll reached 280,000. Compared with the statistical data released by the National Cancer Center in 2019, the incidence and mortality of colorectal cancer in my country are significantly higher than in the past. Therefore, the situation of colorectal cancer prevention and control is not optimistic.

Fortunately, colorectal cancer is a tumor that is especially suitable for early screening. The incidence of colorectal cancer is relatively long, starting from the common precancerous lesions adenomatous polyps, and ending at the early stage. It takes about five to ten years to form cancer, and almost 90% of colorectal cancers develop from this process, so there is a long screening interval for us to participate in to prevent the occurrence of tumors.

Experts recommend that the starting age of colorectal cancer screening for the general population is 40 years old. Now, five common screening methods are recommended as follows:

1. Colonoscopy screening. It is the gold standard for colorectal cancer screening. The endoscopist can completely inspect the entire colorectum under the visual lens, take tissue biopsy for the suspicious lesions found to further clarify the pathological diagnosis, and can also perform endoscopic treatment of early tumor lesions.

2. Immunoquantitative fecal occult blood screening. Human hemoglobin in stool samples is detected by specific antibodies, and high-precision instruments are used to obtain quantitative detection results, which in turn indicate the existence of intestinal lesions. It can be used for the screening of early colorectal cancer. When there is trace bleeding in the lesion tissue, it can be detected from the patient’s feces. It has a sensitivity of 88% and a specificity of 90% for the diagnosis of intestinal disease. Those with positive occult blood screening will undergo targeted colonoscopy to make a final diagnosis, which can greatly improve the disease detection efficiency of colonoscopy.

3. Screening sigmoidoscopy. It can be used for the screening of rectal and rectal cancer and related diseases, and it has high sensitivity and specificity for distal colorectal cancer.

4. Colon CT imaging screening. It can be used for colorectal cancer screening under certain conditions, and has certain screening capabilities for colorectal cancer and precancerous lesions.

5. Multi-target stool DNA detection and screening. Individual comprehensive risk scores are formed by detecting DNA mutations in fecal exfoliated cells by laboratory techniques. Subjects whose comprehensive scores exceed a preset threshold are defined as high-risk groups, and then targeted colonoscopy is performed.

< td>


Screening Technology


Grades of Recommendation

GRADE Evidence

Screening cycles


Gold standard for screening



every 5-10 years


fecal occult blood

It is suitable for colorectal cancer screening, which has high sensitivity for colorectal cancer diagnosis and limited sensitivity for precancerous lesions



every year

1 time


Can be used for colorectal cancer screening, and it has high sensitivity and specificity for distal colorectal cancer


< span>Every 3-5 years

Colon CT

Imaging techniques

can be used for colorectal cancer screening under certain conditions, and have certain effects on colorectal cancer and precancerous lesions Screening capacity



every 5 years


< span>Multi-target stool DNA assay

can be used for colorectal cancer screening under certain conditions, and it can be used for colorectal cancer and precancerous lesions Have certain screening ability



every 3 years


< /td>

As Shenyang City Colorectal Early Cancer Screening and Standardized Diagnosis and Treatment Center, the Municipal Anorectal Hospital undertakes To provide screening and standardized diagnosis and treatment services for early colorectal cancer for the vast number of patients in Shenyang and surrounding areas, our short-term goal is to increase the screening rate of the population and the detection rate of early tumors; our ultimate goal is to reduce the rate of colorectal cancer in the population. Cancer mortality and morbidity.

[Experts in this issue]

Wang Tianfu, Deputy Chief Physician of the Colorectal Early Cancer Screening Center of Shenyang Anorectal Hospital. Engaged in early diagnosis and treatment of gastrointestinal related tumors, good at clinical diagnosis and treatment of various common and difficult diseases of gastrointestinal tract, anus and pelvic floor.