Cancer came from the Latin word "crab" because when you look at a top view of a crab, the legs spread out going every way. That is like what a cancer cell looks like, spreading out through the body. You would be amazed when you look at the number of all of the people who get cancer yearly. About 1 in 3 people get it, that's about 33% of people in the World. About one fourth of those people expect to live for the next five years.
Nobody really knows what triggers cancerous cells. There could be a million different reasons for all we know. Scientists have have a little about what may cause it. They believe that about 35-50% of cancer cells can be triggered by diet, chemicals account for about 40%. Only 5% of those are chemicals other than cigarette smoke. Only 3-4% can be caused by radiation. 7% is unaccounted for. Too much sun can cause skin cancer, and some people think that certain types of sun screen may make someone get skin cancer in the future. Like we said earlier, there are probably thousands of other causes for cancer.
There are several different types of cancer. Cancer cells that start in membranes are called Carcinomas. Ones that start in structures deep inside the body, like in your liver, are called Sarkomas. Cancer cells that grow in connective tissues are called Sarcomas, and ones that start in your blood is Leukemia. Mostly all of them form tumors. A tumor can be either benign or malignant. That means that it doesn't spread, or it does spread.
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This picture taken by an electron microscope. It is a cancer cell being destroyed by white blood cells. |
