Understanding Cancer

Cancer results from a destructive (malignant) transformation (carcinogenesis) of normal cells, causing them to enlarge and divide more rapidly than normal.

Cancer cells tend to be very aggressive and out of control. In contrast, a benign tumor is a localized mass of slowly multiplying cells resembling its original tissue. It's seldom life-threatening.

Cancer cells may invade nearby tissues or spread (metastasize) to other organs, traveling through the circulatory system or the lymphatic system or by seeding into an organ or a body cavity. The pattern and extent of spread determine the cancer's stage.

Measuring the extent that cells have spread is called staging. Depending on the type of cancer, a variety of imaging techniques, such as computer tomography (CT) scan or magnetic resonance imaging (MRI), may be used to stage a tumor.

Due to the variety of cancers, the ideal treatment can range from observation to complicated surgical removal with aggressive therapy. Surgery, radiation therapy, and chemotherapy can be used in combination or as individual treatments. In surgery, the diseased part of the body is removed. Neighboring healthy lymph nodes and tissues may also be removed to help control the cancer's spread.

High energy rays, focused in a beam, are used to damage the cancer cells and stop their reproduction. This local therapy is used to shrink a cancer's size either before surgical removal or after, to kill any remaining cancer cells.

Drugs given at specified intervals to enhance effectiveness and limit adverse effects disrupt the ability of cancer cells to divide. These drugs travel through the blood to act on dividing cells ― both normal and cancerous ― throughout the entire body.