cancer
Understanding CancerCancer begins in cells, the building blocks that form 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 old 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.
Benign tumors are not cancer:
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 old 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.
Benign tumors are not cancer:
- Benign tumors are rarely life-threatening.
- Generally, benign tumors can be removed, and they usually do not grow back.
- Cells from benign tumors do not invade the tissues around them.
- Cells from benign tumors do not spread to other parts of the body.
- Malignant tumors are generally more serious than benign tumors. They may be life-threatening.
- Malignant tumors often can be removed, but sometimes they grow back.
- Cells from malignant tumors can invade and damage nearby tissues and organs.
- Cells from malignant tumors can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumor and entering the bloodstream or lymphatic system. The cells can invade other organs, forming new tumors that damage these organs. The spread of cancer is called metastasis.