Colorectal cancer is one of the most common malignant tumors. Its incidence ranks third in the world as malignant tumors, and its mortality rate ranks second in the world. It is the malignant tumor of the digestive system that accounts for the highest incidence and death globally.
In recent years, the incidence of colorectal cancer in China has shown an overall upward trend, and it has become the second most common malignant tumor in the digestive system in China. In 2018, there were 376,000 new cases of colorectal cancer in China and 191,000 deaths.
Why is the incidence and mortality of colorectal cancer so high? How to prevent it?
More than 85% of colorectal cancer is found to be advanced
According to relevant data, the current 5-year survival rate of colorectal cancer in China is much lower than that of the United States, Japan, and South Korea. More than 85% of colorectal cancers are already at an advanced stage once discovered.
Why are most colorectal cancers only discovered in advanced stages?
1. Early colorectal cancer or asymptomatic and good at disguising
Late colorectal cancer may show changes in bowel habits, constipation, diarrhea, blood in the stool, abdominal pain, bloating, intestinal obstruction and other gastrointestinal symptoms, as well as systemic manifestations such as anemia, fatigue, fatigue, and fever. However, early colorectal cancer may have no obvious symptoms.
These symptoms are easily confused with symptoms of other diseases such as hemorrhoids, and are easily treated as common diseases by patients. Therefore, once bowel cancer is discovered, it is often in the middle and advanced stages, and the best time for treatment is missed.
2. Chinese people are not very aware of screening
For colorectal cancer, early screening is the best prevention method, early detection, early treatment, and a relatively high cure rate!
For advanced colorectal cancer, even after comprehensive treatment such as surgery, radiotherapy, chemotherapy, and targeted therapy, the 5-year survival rate of patients is still significantly lower than 40%; on the contrary, the 5-year survival rate after treatment for early colorectal cancer can exceed 95%, even It can be completely cured.
However, at this stage, the diagnosis rate of early colorectal cancer in China is less than 10%. This is related to the lack of awareness of early screening among Chinese residents. They often think of colorectal cancer screening when they have particularly uncomfortable symptoms. In the first year of physical examination, I will also give up screening because I have a bad experience such as having a colonoscopy, which makes it difficult to detect bowel cancer early.
It should be understood that due to obesity and poor eating habits, the incidence of colorectal cancer in developed countries is usually higher than that in developing countries. However, although the incidence of colorectal cancer in the United States and some European and American countries is high, the mortality rate has continued to decrease in the past 25 years, and the decline in men has been 47% of women, a decrease of 44% for women, thanks to the popularity of screening.
According to the 2018 American Cancer Annual Report, only from 2000 to 2015, the proportion of people over the age of 50 using colonoscopy in the United States tripled (from 21% in 2000 to 60% in 2015). Although there are more early patients, the cure rate is All are above 95%.
People over 50 should be screened annually
Both clinical research and practice for colorectal cancer screening show that screening is the most effective means to reduce the mortality rate of colorectal cancer.
According to China's national conditions and clinical epidemiological data of colorectal cancer, population screening recommends 50-75 years as the target age group; people with family history can advance to 40 years old, and if there are intestinal polyps, they should be reviewed regularly every year. For people with related symptoms and signs, especially warning symptoms such as blood in the stool, blood in the mucus in the stool, changes in bowel habits, unexplained anemia, weight loss, etc., age restrictions are not required and should be screened as soon as possible.
Specifically, the following groups of people need early screening:
1. First-degree relatives have a history of colorectal cancer
2. I have a history of cancer (any malignant tumor history)
3. I have a history of intestinal polyps
4. Those who have 2 or more of the following
(1) Chronic constipation (constipation of more than 2 months per year in the past 2 years);
(2) Chronic diarrhea (diarrhea has lasted more than 3 months cumulatively in the past 2 years, and the duration of each episode is more than 1 week);
(3) Mucus and blood in the stool;
(4) History of chronic appendicitis or appendectomy;
(5) History of chronic biliary disease or history of cholecystectomy.
Warm reminder: Those who meet any of the above items or more are all high-risk groups of colon tumors, and it is recommended to screen as soon as possible.
1% increase in colonoscopy rate
3% lower risk of death from colorectal cancer
There are many ways to screen for colorectal cancer, the following 8 are commonly used:
• Fecal occult blood test: chemical fecal occult blood test, immunochemical fecal occult blood test
• Fecal DNA testing
• Sigmoidoscopy screening
• Colon CT imaging technology
• Colon capsule endoscopy screening
• Plasma Septin9 (SEPT9) gene methylation detection
• Fecal pyruvate kinase (M2-PIE) test
Among them, colonoscopy occupies a unique and irreplaceable position in colorectal cancer screening, and is the core link of the entire colorectal cancer screening process. Colonoscopy can directly observe the inner wall of the colorectal cavity, which is the most sensitive way to find intestinal tumors. For every 1% increase in the colonoscopy rate, the risk of death from colorectal cancer will be reduced by 3%.
 Bai Yu, Yang Fan, Zhao Shengbing, Pan Peng, etc. Expert consensus on the screening process for early colorectal cancer in China (2019, Shanghai) [J]. Chinese Medical Journal, 2019(38):1-10