Cancer
Bladder Cancer
Breast Cancer
Colon And Rectal Cancer
Kidney Cancer
Cancer of the Larynx
Leukemia
Non-Hodgkin's Lymphoma
Lung Cancer
Melanoma
Ovarian Cancer
Prostate Cancer
Skin Cancer
Stomach Cancer
Cancer of the Uterus
All Other Cancers

What Is Cancer?

Cancer is a group of many different diseases that have some important things in common. They all arise in cells, the body's basic unit of life. To understand different types of cancer, it is helpful to know about normal cells and what happens when they become cancerous.

The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes cells keep dividing when new cells are not needed. These cells may form a mass of extra tissue called a growth or tumor. Tumors can be "benign" or "malignant".

• Benign tumors are not cancer. They can usually be removed, and in most cases, they don't come back. Most important, the cells in benign tumors do not invade other tissues and do not spread to other parts of the body. Benign breast tumors are not a threat to life.
• Malignant tumors are cancer. Cells in these tumors can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or lymphatic system. That is how breast cancer spreads and forms secondary tumors in other parts of the body. The spread of cancer is called metastasis.