Balanced diet interrupts the sneak attackof colorectal cancer

　　In April, the Global Burden of Disease,Injury and Risk Factors Study Group released a report on the global burden ofdisease for colorectal cancer from 1990-2019. The report noted that in the past30 years, colorectal cancer cases worldwide jumped from 842,000 to 2.17million, and deaths increased from 518,000 to 1.09 million. With the continuousdevelopment of economy and society and the change of people's lifestyle, theincidence rate and mortality rate of colorectal cancer in China are also on therise. What are the clinical manifestations of colorectal cancer? What are themost common causative factors? How to prevent it in daily life? What benefitswill a balanced diet bring? Recently, Huang Rui, an expert of CFS, a member ofTumor Metastasis Committee of China Anti-Cancer Association and a professor ofColorectal Oncology Surgery of the Second Affiliated Hospital of Harbin MedicalUniversity, made a popular interpretation of these concerns, aiming to let thepublic have a deeper understanding of the hazards of colorectal cancer and stopthe attack of colorectal cancer from the source.

　　Data show that the incidence rate ofcolorectal cancer in China ranks the second in malignant tumors and themortality rate ranks the fourth in malignant tumors, and the trend of youngerpopulation is becoming more and more obvious. The study also found that theincidence of colorectal cancer in China has certain geographicalcharacteristics, for example, the incidence rate in urban areas is higher thanthat in rural areas, and the incidence rate in developed areas is higher thanthat in less developed areas, among which the incidence rate in eastern areasis 33.37%, which is significantly higher than that in other areas. Expertsbelieve that there may be a positive correlation between the incidence ofcolorectal cancer and the improvement of living standards. Some studies haveshown that the risk of colorectal cancer is pulled up when the intake ratio offat, red meat and sugary drinks in the diet structure increases.

　　Huang Rui introduced that colorectalcancer, commonly known as colorectal cancer, is insidious and silent, and manyearly colorectal cancers and precancerous lesions do not even have any"traces", or only feel discomfort, indigestion, fecal occult blood.As the cancer progresses, the symptoms such as change in stool habit, abdominalpain, blood in stool, abdominal mass, intestinal obstruction, etc. will appear,and some of them may be accompanied by systemic symptoms such as anemia, feverand emaciation. From the anatomical pathogenesis of colorectal cancer, theincidence of colorectal cancer is from high to low: rectum, sigmoid colon,cecum, ascending colon, descending colon and transverse colon, and there is atrend of development to the proximal end (right hemicolectomy). In addition,colorectal tumors can also metastasize and infiltrate other organs, spreadingto liver, lung, bone, brain, ovary and other important parts, resulting inserious consequences.

　　Huang Rui said, at present, the cause ofcolorectal cancer is still unclear, but there is a lot of research evidenceshowing that colorectal cancer is closely related to the patient's environment,gender, age, family genetics, lifestyle, diet and nutrition, disease drugs andother factors.

　　Firstly, environmental geography.According to the world epidemiological survey, colorectal cancer has thehighest incidence rate in North America, Western Europe, Australia and NewZealand, ranking among the top two visceral tumors, but the incidence rate islow in Asia, Africa and Latin America. According to the statistics of theNational Cancer Center, the incidence of colorectal cancer in China is in theorder of eastern, central and western regions; in the east, the incidence ishigh in the middle and lower reaches of Yangtze River, such as Shanghai andZhejiang. Thus, colorectal cancer is a disease of the rich and the poor.

　　The second is gender and age. There aremore men than women with colorectal cancer, and the incidence rate is highestin the age group of 40-50. In 2015, for example, there were 388,000 new casesof colorectal cancer in China, accounting for 9.9% of all malignant tumorcases, of which 225,000 cases were men and 163,000 cases were women. Meanwhile,the incidence rate of colorectal cancer is at a low level before the age of 25,and climbs rapidly after the age of 25, reaching the "ceiling" at theage of 80-84. The incidence of colorectal cancer also increases inpostmenopausal women, and it is assumed that estrogen/progesterone may haveanti-cancer effects through a number of biological reasons. When women reachthe middle and later years, the level of estrogen/progesterone in their bodiesgradually decreases, and they naturally lose their defensive function.

　　Third, family history. Family history ofcolorectal cancer is strongly associated with increased risk of colorectal cancer.A quantitative systematic analysis by foreign scholars of 63 studies with atotal of 9.28 million people found that the risk of colorectal cancer amongfirst-degree relatives (parents, children and close siblings) was 1.76 timeshigher than that of the general population. A cohort study in China included atotal of 73,358 women with an average follow-up time of 7 years and showed thatthe risk of colorectal cancer in women with first-degree relatives was 2.07times higher than that in the general population.

　　Fourth, inflammatory diseases. Certainpatients with inflammatory bowel disease and diabetes are often considered tobe at high risk of developing colorectal cancer. Among them, patients withinflammatory bowel disease, including ulcerative colitis and Crohn's disease,are 2.4 times more likely to develop the disease than the general population;while patients with diabetes have 1.38 times and 1.20 times the risk of colonand rectal cancer, respectively, than the healthy population. In addition, polypsand adenomas contribute significantly to the formation of colorectal cancer.

　　Fifth, dietary nutrition. Obesity is theroot cause of many diseases and is likewise one of the scourges of colorectalcancer. For every 5 increase in body mass index, the risk of colorectal cancerincreases by 5%; for every 10 cm increase in waist circumference, the risk ofcolorectal cancer increases by 2%. Data from domestic studies show that forevery 1 standard deviation increase in waist circumference, the risk of colorectalcancer increases by 16% in Chinese people. Another study reported that forevery 10g, 90g and 400g increase in daily dietary fiber, whole grain and dairyintake respectively, the risk of colorectal cancer incidence was reduced by 9%,17% and 13% respectively.