Cancer is any of more than 100 diseases characterized by excessive, uncontrolled growth of abnormal cells, which invade and destroy other tissues. Cancer develops in almost any organ or tissue of the body, but certain types of cancer are more lethal than others. The condition is caused by the presence of a malignant tumor or growth that arises when cells multiply uncontrollably, destroying healthy tissue. The different forms are sarcomas, carcinomas, leukemias, and lymphomas.
