Colorectal cancer metastasizes directly from the inner lining through the muscle wall of the intestine and into adjacent tissues. It may metastasize through the lymphoid system to nearby lymph nodes, to the liver and sometimes through the bloodstream to the bones or lungs. The most common type of colorectal cancers are adenocarcinomas, which develop in the glands of the inner lining of the colon or rectum. Advancing age, usually being older than age 40, is the single most important risk factor for the development of colorectal cancer. A diet high in animal fats and low in fiber, High consumption of charcoal-broiled foods, Inactivity and constipation, and Workers exposed to asbestos and glue.
Colorectal cancer can cause different symptoms based on the location of the tumor.
Cancers of the right colon often result in frequent blood in the stool, but usually do not block the colon. Cancers in the left colon may obstruct the bowel, causing a change in bowel habits, diarrhea or constipation and changes in stool size. A feeling that the bowel does not empty completely, and As in all cancers, fatigue, weight loss and loss of appetite are common symptoms. Surgery is the most common treatment. Most patients have part of the colon or rectum removed in an operation called a colectomy.