On this page:

• What is Cancer?
• Signs of Cancer
• Cancer Stages

What is Cancer?

Cancer is not one particular disease but rather a group of diseases in which abnormal cells grow in an irregular way.

Our bodies are made of billions of normal cells that are like the bricks and mortar of a building. Each tiny cell has a specific job to do, whether it's relaying messages to the brain, digesting food or pumping blood.

Normal cells grow and divide in an orderly fashion and respect the boundaries of neighboring cells.

A cancer usually develops from a normal cell that has changed or mutated. The change or mutation that occurs in the cell is usually from an unknown cause. However, changes may occur because of a virus, chemical or radiation injury, or a family predisposition.

This abnormal cell grows without following the rules that direct normal cells. Some cancers grow quickly; others more slowly. As the cancer grows, it can invade normal organs, causing normal body functions to be compromised or stopped. Tumors can squeeze organs or block passages. This will eventually cause symptoms or problems.

Cancer also tends to spread (metastasize) to other parts of the body. This spread is accomplished in one of three ways:

• By directly moving from the tumor to other body parts. Projections from the main tumor can be seen.
• By crossing into the blood vessels and floating along until the cancer cell takes root in another area.
• By crossing into the lymph system which normally acts as a filtering system for bacteria and debris.

Eventually the lymph system empties into the blood. A cancer cell may be trapped in a lymph node (filtering station) and grow there or it may find its way into the blood stream and the rest of the body.

For more information, read "Understanding Cancer," a Health Talk & You article published by the University of Minnesota Academic Health Center.

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Signs of Cancer

Most cancers in their earliest stages do not cause symptoms or pain. That's why you should see your doctor for regular checkups and not wait for problems to occur. But you should also know that the following symptoms may be associated with cancer:

• Changes in bowel or bladder habits
• A sore that does not heal
• Unusual bleeding or discharge
• A thickening or lump in the breast or any other part of the body
• Indigestion or difficulty swallowing
• An obvious change in a wart or mole
• A nagging cough or hoarseness

These symptoms are not always a sign of cancer. They can also be caused by less serious conditions. Only a doctor can make a diagnosis. It is important to see a doctor. Don't wait to feel pain. Early cancer usually does not cause pain.

Source: What You Need to Know About Cancer, National Cancer Institute, NIH Publication No. 94-1563, Revised April 1993.

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Cancer Stages

Cancers are often "staged" or rated on how extensive they are before treatment. By determining the correct stage, a physician can plan the best therapy and evaluate the results. Many systems are used to stage or grade tumors. The earlier the stage when diagnosed, the greater the opportunity for cure or improvement. Typically, the stages are:

• Stage I, the simplest form, indicates that the tumor is small and confined to the organ or tissue where it began. The best chance for cure is when the tumor is still in Stage I.
• Stage II means the tumor has spread to surrounding tissues.
• Stage III means the tumor has spread into surrounding tissues and lymph nodes.
• Stage IV signifies more extensive spread, often to many organs or parts of the body.

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