Cancer is a complicated disease often described by those who know it well in confusing medical, technical, and scientific terms. There's a way to understand it in simple terms, though. And a recent CBS news story features a great run-down on the disease, its causes, how it grows, and more.Think about this:
- Cancer refers to any one of a large number of diseases characterized by the uncontrollable growth of abnormal cells. These cells have the ability to infiltrate and destroy normal tissue and can spread -- metastasize -- throughout the body.
- Cancer is caused by damage in the DNA. DNA is like a set of instructions for cells and tells cells how to grow and divide. Normal cells can develop mutations in their DNA but can repair most of them. If they cannot make a repair, the cells often die. But certain mutated cells don't repair and don't die. They instead grow and become cancerous.
- Normal, healthy cells grow in an orderly, well-controlled way. They live for a set period of time and then die on schedule. Dead cells are replaced by new normal cells. Cancer cells, in contrast, grow in an uncontrolled manner. They don't die. They accumulate. One malignant cell becomes two, two become four, four become eight, and so on, until a mass of cells -- a tumor -- is created. Tumors remain small until they're able to attract their own blood supply, which allows them to obtain the oxygen and nutrients they need to grow larger.
- Not all cancers form tumors. Leukemia, for example, is a cancer of the blood, bone marrow, lymphatic system, and spleen.
- Cancer can take decades to develop. By the time a cancerous mass is detected, it's likely that 100 million to one billion cancer cells are present, and the original cancer may have been dividing for five years or more.
- Lung cancer is the top cancer killer among men and women and will kill 160,390 people in 2007.
