the exact cause of colorectal cancer is not known. most cases begin as small growths or polyps inside the intestine. if colorectal cancer is not detected and removed it invades and destroys nearby tissues and may spread to other parts of the body. webmd medical reference from healthwise this information is not intended to replace the advice of a doctor. healthwise disclaims any liability for the decisions you make based on this information. © 1995-2011 healthwise incorporated. healthwise healthwise for every health decision and the healthwise logo are trademarks of healthwise incorporated.
what causes colorectal cancer metastatic or recurrent?