WHAT IS CANCER?

In a healthy body, there are natural mechanisms that regulate the creation, growth and death of cells (called apoptosis). Through the natural cycle of life, cells divide to create new tissue as older cells die off. When tissue is injured, for instance by a cut on the hand, the body's cell growth regulators react by speeding up the process of cell division to create new tissue in the injured area as fast as possible. When the body has healed, the creation of new tissue through cell division goes back to the normal pace.

Cancer is a disease where the natural regulators malfunction and cells do not die off at the right rate. There is a failure of apoptosis, and as a result, cell growth exceeds cell death. Cancer cells divide without their normal control, accumulating into a mass of extra tissue—a tumor. As a tumor grows, it promotes the formation of new blood vessels (called angiogenesis) to bring in the oxygen and nutrients it needs. Cancer cells can also leave the tumor site and travel through the blood stream and lymphatic system (the network connecting lymph nodes throughout the body) to other parts of the body, such as the liver, lungs or bones. This process of cancer cells leaving the original tumor and appearing elsewhere is called metastasis (meh-TAS-ta-sis). In the new location, cancer cells may again begin to divide abnormally to create a tumor. A person with cancer may eventually die of the disease if vital organs like the liver or lungs are invaded and destroyed.

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