Colon cancer
1. Introduction:
Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body. Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place. Sometimes this orderly process goes wrong. New cells form when the body does not need them, and cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor. Tumors can be benign or malignant: