Cancer 101
What You Should Know about the Basics

The more we learn about cancer, the more answers and insights we have into its many forms. Before considering some of those answers, let's start with the most basic question:

What is cancer?


    a. Cells that eat up other cells in the body.
    b. Cells that grow more rapidly than normal cells.
    c. Cells that are caused by excessive stress in the body.
    d. None of the above.

The correct answer? None of the above. Cancer cells do not devour other cells and are not caused by stress. And it may be surprising to learn that cancer cells grow no faster than normal ones. To understand the true nature of cancer, we first need to understand the life of normal cells.

Over the course of a week or perhaps a few months, a normal cell is born, matures, does its job, grows old and dies. A replica takes its place, and goes through the same life cycle. Cells that become cancer miss steps in this cycle, including the ability to age and die. Instead, they persist and reduplicate, producing yet another cell with the same inability to mature, age and die.

Chemicals are responsible for stimulating chromosomes to send messages to normal cells to tell them what to do and when to do it. The chromosomes in cancer cells are sometimes abnormal, or they receive abnormal stimulants and send the wrong messages. We don't yet know all of the causes of these abnormalities, but we do know about many of them. Excessive stimulants can come from the outside, (such as chemicals associated with smoking), and irritate or alter the chromosomes or basic chromosome abnormalities may occur from viruses. At times there may be highly sensitive chromosomes that we inherit.

In the fight against cancer, the safety and effectiveness of treatments has increased along with our knowledge of how cancer cells live and replicate. In the past, malignancy was treated only with drugs (chemotherapy) that enter rapidly dividing cells and try to destroy them. Chemotherapy is frequently effective, but it also may destroy normal cells that can grow more rapidly than cancer cells, such as hair, mouth, intestinal and bone marrow cells.

Today, the treatment of cancer is being revolutionized by what researchers learned as they mapped DNA in the Human Genome Project. This has let us look inside a cancer cell at its chromosomes and messages. Now we have the ability to identify abnormalities of cancer cells at the molecular level and isolate the defects responsible for abnormal growth.

This is a brief review of our understanding of malignancy today. The mysteries of cancer cells are being rapidly unraveled. Already, we have examples of older chemotherapy drugs being replaced with specific agents that "teach" cancer cells to re-regulate their abnormalities. In the days ahead — in this new field of molecular oncology and others — we look forward to the development of even more effective treatments, less invasive procedures and a greater quality of life for every individual who faces this disease.

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Neil Abramson, MD, is Director of Education and Clinical Research at Baptist Cancer Institute, the region's full-service cancer center, and Clinical Professor of Medicine at University of Florida – Jacksonville.

He is the recipient of the 2003 Outstanding Clinical Research Award from the American Society of Clinical Oncology.