1998 Cancer is a class of diseases characterized by an uncontrollable rate of cell division. It has been known for almost 3,500 years and there are even documentation of it in ancient medical writings, such as Ebers and Edwin Smith papyruses.
Cancer affects many species besides mammals, including fish, reptiles, and birds.
Due to their rapid growth, cancerous cells quickly infiltrate the adjacent tissues, taking up their nutrients and space. They eventually gain access to the circulatory system which transports them to other parts of the body and culminates in host's death. Modern cancer therapy involves a combination of chemotherapy, surgery and radiation. Chemotherapy has become the major focus of oncological research and drug development because of its increased selectivity and effectiveness over the other two treatments. Much of the recent research, furthermore, has focused on natural products as sources of potential anticancer compounds.