Cancer is an uncontrolled growth of cells that can occur in any tissue in the body. All cancers occur as a result of damage or changes in the genes of a cell. Most often several changes in different genes contribute to cause a cancer to develop and progress. Cancers can be described as either benign or malignant.
Benign cancers tend to stay in a single part of the body without spreading.
This process of spreading from an original tumor to another part of the body is known as metastasis. A tumor can metastasize through the blood stream or through the lymphatic vessels of the body. Cancers can develop from any normal part of the body. The tissue type from which a cancer develops as well as the underlying genetic changes associated with the cancer largely determines the behavior of cancer. Considerable progress has been made in our understanding of the causes of cancer.