The cells divide uncontrollably and may grow into adjacent tissue or spread to distant parts of the body. Adenocarcinomas are cancers that form on a glandular surface, such as the lung, breast, prostate, ovary, or kidney. Sarcomas are cancers that occur in supporting structures, such as bone, muscle, cartilage, fat, or fibrous tissue. Leukemias and lymphomas are cancers that occur in blood cell elements. Brain cancers, nerve cancers, melanomas, and certain testicular and ovarian cancers do not fall into a general category.
Cancers begin in a single cell, and that cell is the site of the primary cancer.
The cancer is named for the primary site of origin, such as skin, colon, or breast. Liver cancers are those that originated from a liver cell. If it spreads to the lung, it is still liver cancer, not lung cancer. When cancer spreads to the regional lymph nodes, those nodes are said to contain metastatic cancer. Cancer can spread from its original location to other parts of the body.