Canavan disease

cancer An abnormal growth of cells that tend to proliferate in an uncontrolled way and, in some cases, to metastasize (spread) to other areas of the body. Cancer is not one disease; rather, it is a host of more than 100 different and distinctive diseases. A tumor can involve any tissue of the body. Most types of cancer are named for the type of cell or organ in which they start. If a cancer metastasizes, the new tumor bears the same name as the original primary tumor. Skin cancer is the most common type of cancer in both men and women. The second most common types of cancer are prostate cancer in men and breast cancer in women. Lung cancer is the leading cause of death from cancer for both men and women in the US. Cancer is not contagious. Also known as malignancy, malignant tumor, and malignant neoplasm. See also cancer, causes.