Then normal cells divide only to replace dying cells and to repair injuries. Cancer cells, however, continue to grow and divide, spreading to other parts of the body and accumulating to form tumors that destroy normal tissue. In their new location, the cancer cells continue growing and spread to a new site, metastasis. When cancer spreads it is still named after the part of the body where it started. Different types of cancer vary in their rates of growth, patterns of spread, and responses to different types of treatment.
Different cancers have different risk factors.
Causal factors may act together or in sequence to initiate or promote cancer. Many people with one or more risk factors never develop cancer, while others with this disease have no known risk factors. Ten or more years can pass between exposures or mutations and detectable cancer. In the US, men have a one in two lifetime risk of developing cancer, women one in three. Staging is the process of describing the extent of the disease or the spread of cancer from the site of origin.