Cancer is a group of diseases characterized by the uncontrolled growth and spread of abnormal cells.
Both external and internal factors cause cancer. Factors such as chemicals, radiation, viruses, hormones and inherited mutations may act together to start or further cancer. Ten or more years may pass between exposure and detectable cancer. Anyone, from children to senior citizens. In the 1980's, there were over 4.5 million cancer deaths, almost 9 million new cancer cases, and about 12 million people under medical care for cancer.