Status of colorectal cancer (a) morbidity and mortality
The world average incidence of colon cancer was 16.6/10 million men, women 14.7/10 million; average incidence of cancer for men 11.9 / 100,000, female 7.7/10 million. The world, Hawaii's Japanese-American male colon cancer incidence rate was the highest 37.15n million; women of New Zealand highest 30.46/10 million. The lowest incidence of colon cancer between men and women in Africa and India. Men around the world the highest incidence of colorectal cancer in Hungary, up to 20.46/10 million; women of New Zealand highest 12.31/10 million.
In the U.S., colorectal cancer ranks second cause of cancer death, behind lung cancer. 1977 average adjustment of colorectal cancer mortality 3.54/10 million, accounting for 5.29% cancer death, ranking sixth; 1990 "- '1992 National sample survey of one-tenth of the population, colorectal cancer mortality rate was 4.54 average adjustment / 10 million, accounting for 4.9% of cancer deaths, ranking the fifth largest city in China at present colorectal cancer incidence and mortality rank second.
(B) the geographical distribution of
Colorectal cancer is one of the most common gastrointestinal cancer, there are significant differences in geographical distribution, high incidence, such as North America, Western Europe, Australia and New Zealand; in the prone areas such as Eastern Europe, Southern Europe, Latin America; low incidence regions such as Africa, Asia and South America. In areas with high and low morbidity and mortality of a difference of as much as 10 "- '20 times. In China, the incidence of colorectal cancer mortality in the geographical distribution and characteristics: the eastern coastal areas than inland northwest high, the tallest of the Yangtze River region, which is a high incidence of economically developed areas, urban than rural high, big cities and smaller urban high.
(C) population distribution
1. Age
Age of the domestic to 40 "- '60-year-old up, but 30 years of age account for 1 / 5. Literatures the youngest, 9 months. Sun Yat-sen Cancer Hospital data, 57.5% 40-59 years old, the youngest, 7-year-old . of patients with colorectal cancer younger than 12-18 years earlier reported in Europe and America.
2. Gender
In other countries, the incidence of little difference between men and women. In Taiwan, more men than women, about 2:103. Race by the migration of colorectal cancer to the high incidence of low-incidence area of the second generation immigrants, the incidence rate, location and distribution of mortality and morbidity is similar with the local population, and significantly higher than local residents. Thus speculated that the incidence of colorectal cancer and environmental factors, living habits and diet, but not with race relations is not.
(D) the time trend
Colorectal cancer incidence and mortality changes over time. Different changes in different regions, the original high incidence rate of easing rising or falling, but the low, medium hair area continued to rise. The United States from 1973 to 1995, 20.5% colorectal cancer mortality, the incidence rate dropped 7.4%, in particular the decline rate accelerated after 1986. So far, the world incidence of colorectal cancer was still increased by 2% per year. Past two decades, China's colorectal cancer incidence time trends as well. A Case of Shanghai, 1993 — 1994 compared with 19,721,974 men and colon cancer increased 104%, 99% increase in female, male and female standardized incidence rate of colon cancer increased by 100%, an annual increase of 4%. In 1999, the men and women were 16.2/10 million colon cancer, and 14.5/10 million. Smaller rate of increase of rectal cancer for men increased by 11%, 7% of women. In short, compared to 90's and 70's, the incidence of colorectal cancer in the city rose 31.95 percent, rose 8.51% in rural areas.
(E) epidemiological features of colorectal cancer
(1) more males than females;
(2) significantly earlier age of onset, our median age of onset of colorectal cancer was 50 — 55 years earlier than in Europe and other countries 12-18 years;
(3) cancer more common than colon cancer, colorectal cancer in China accounted for more than 50%, colorectal cancer, 80% of the tumor is located away from the dirty door 8em below the rectal examination found the Book of Changes, Europe and the United States Zeyi colon cancer is more common;
(4) combined schistosomiasis are more domestic in Jiangsu and Zhejiang as high, consistent with the schistosomiasis endemic areas, where colorectal cancer is often associated with schistosomiasis.
Status of colorectal cancer causes of colorectal cancer as the other, as yet clear, but it has been noted with the following factors may be relevant.
1. Genetics and Colorectal Cancer
The risk of colorectal cancer in the general population is 1 / 50, the first generation of pro-cancer patients increases the risk three times: 1 / 17, generation of any two of the pro-cancer, the risk rose to 1 / 6. The family history of colon cancer is more common than cancer. L is generally believed that dietary factors, high animal protein, high fat and low-fiber diet is the high incidence of colorectal cancer factors. Eating fatty, too much bile secretion, followed by acid decomposition products will rise, also increased activity of intestinal anaerobic bacteria that may cause intestinal carcinogens, tumor promoters increase in the original form, leading to colorectal carcinogenesis. For example, anaerobic fusiform bacillus deoxycholic acid can be transformed into 3 – A E benefits, which has proved to be carcinogenic.
Established non-cancerous colon diseases such as chronic ulcerative colitis, polyposis, adenoma and so on. It is estimated that about 3% -5% of ulcerative colitis a major Young cancer. History of ulcerative colitis for 20 years to cancer 12.5%; 30 years, up to 40%. Some people think that about 15% – 40% of the cancer originated in the colon with multiple polyps, the pre-cancerous disease duration was 52 years. Adenoma to cancer, cancer rates in diameter were 0.9%, 1em, 2.5em diameter of more than 12% of cancer 4. Parasitic diseases of data shows that about 10.8% _14. 5% of the change late schistosomiasis concurrent colon cancer. In Egypt, schistosomiasis mansoni colorectal cancer combined accounted for 12.5% _17. 34%.
5. Other
For example, the relevant environmental factors and colorectal cancer, lack of aluminum regional colorectal cancer, colorectal cancer in asbestos workers pay more. Another example is the bowel habits, stool volume, intestinal bacteria and the relationship between colorectal cancer study some people.
Understanding of the above risk factors, conducive to the prevention of colorectal cancer occurred.
(1) reasonable arrangements for meals: eat more fresh vegetables, fruits and other carbohydrate-rich foods and crude fiber. Adequate intake of calcium, aluminum, smashing help prevent colon cancer. Dietary calcium in the intestine and bile acid, forming insoluble calcium compound, protect the intestinal mucosa against bile acid toxicity damage from the anti-cancer effect.
(2) actively controlling.
(3) active treatment of ulcerative colitis, polyps and adenomas.
Status of colorectal cancer (4) Census: The population census, the large intestine of early diagnosis and treatment of diseases, the prevention of colorectal cancer development and prevention of colorectal cancer to the late, have an important role in reducing mortality. Available in the population census sequential fecal occult blood test, that is, first discovered by chemical screening positive patients, and then removing the false-positive immunoassay, and finally confirmed by endoscopy.