(1) the occurrence of colorectal cancer are obvious areas of medical experts who have found tumor epidemiological studies, North America, Europe and Australia, the incidence of high and the low rate of the Japanese disease. The incidence of colorectal cancer is the first 4-6 bit about common malignancy. Generally considered in the area south of the Yangtze River, especially with the prevalence of schistosomiasis in Japan than the high incidence of the northern region.
(2) anorectal diseases colorectal adenomas, colorectal cancer patients after recurrence of colorectal cancer easy. Japan's survey found that the people in anorectal diseases detection of colorectal cancer than the average person to a high 4-8 times removed colorectal adenoma after 1 / 3 of the above, there is other parts of the colon tumor. Following further extraction, carcinogenesis may occur. Colorectal cancer patients after another with the risk of colorectal cancer than the general high three times.
(3) patients with colorectal cancer family members opportunities than most people more than three times, but patients with colorectal cancer patients spouse's parents, brothers, sisters and women suffering from colorectal cancer incidence rate has not increased. This shows that in addition to dietary factors, genetic factors in the pathogenesis of colorectal cancer should not be overlooked.
(4) the post-operative breast cancer risk of colorectal cancer patients received pelvic radiotherapy part to the incidence of colorectal cancer than the average person four times higher, most occurred in radiotherapy after 10-20 years.
(2) anorectal diseases colorectal adenomas, colorectal cancer patients after recurrence of colorectal cancer easy. Japan's survey found that the people in anorectal diseases detection of colorectal cancer than the average person to a high 4-8 times removed colorectal adenoma after 1 / 3 of the above, there is other parts of the colon tumor. Following further extraction, carcinogenesis may occur. Colorectal cancer patients after another with the risk of colorectal cancer than the general high three times.
(3) patients with colorectal cancer family members opportunities than most people more than three times, but patients with colorectal cancer patients spouse's parents, brothers, sisters and women suffering from colorectal cancer incidence rate has not increased. This shows that in addition to dietary factors, genetic factors in the pathogenesis of colorectal cancer should not be overlooked.
(4) the post-operative breast cancer risk of colorectal cancer patients received pelvic radiotherapy part to the incidence of colorectal cancer than the average person four times higher, most occurred in radiotherapy after 10-20 years.
