Cancer is actually many different diseases with many causes.
Scientists have learned that cancer can develop in the body's cells through a series of separate changes that can take place over a period of years. Many things can affect whether of not the changes occur. One factor is the genes that a person is born with. Carcinogens include certain manmade and natural chemicals that may be present in air, water, food and the workplace. There are three major kinds of treatment for cancer - surgery, radiation therapy, and and chemotherapy.