The following is a list of cancer types. Cancer is a group of diseases that involve abnormal increases in the number of cells, with the potential to invade or spread to other parts of the body. Not all tumors or lumps are cancerous; benign tumors are not classified as being cancer because they do not spread to other parts of the body. There are over 100 different known cancers that affect humans. For some common cancers, the English organ name is used. For example, the most common type of breast cancer is called ductal carcinoma of the breast.