Common causes of colorectal cancer

Colorectal cancer is a malignant tumor of the large intestinal mucosal epithelium, including colon cancer and rectal cancer. It is a very common malignant tumor, and its cause is not yet fully understood. Currently, it is mainly believed to be a combination of environmental and genetic factors.

Environmental factors

Among various environmental factors, diet is the most important. The incidence of colorectal cancer is positively correlated with the high fat consumption in the food. It is generally believed that high-fat diet and insufficient dietary fiber are the main related factors, which has been proven by a large number of epidemiological and animal experiments.

Genetic factors

From a genetic point of view, colorectal cancer can be divided into hereditary (familial) and non-hereditary (sporadic). Typical examples of the former include familial polyposis coli syndrome and familial hereditary non-polyposis colorectal cancer. The latter is mainly caused by gene mutations caused by environmental factors.

Risk factors

High-risk factors are not direct causes of disease, but they can increase the probability of developing colorectal cancer.

1. Adenomatous polyps of the colon

It is generally believed that most colorectal cancers originate from adenomas, so adenomatous polyps are considered precancerous lesions. The incidence of colorectal cancer in patients with one adenoma is 5 times higher than that in patients without adenoma, and the incidence in patients with multiple adenomas is 1 times higher than that in patients with a single adenoma.

2. Inflammatory bowel disease

Ulcerative colitis can lead to cancer, which is more common in patients with early onset, widespread lesions and a long course of illness.

3. Cholecystectomy

Statistics show that the incidence of colorectal cancer increases after cholecystectomy, which is believed to be related to the increase in secondary bile acids entering the large intestine.