What are the different types of cancer?
Cancers are usually named according to 2 characteristics:
1. the organ or part of the body where they start
A cancer starting in the breast is a breast cancer. The same is true for almost all cancers like, amongst others, ovarian cancer, lung cancer, prostate cancer or larynx cancer.
2. the type of cell that initially became abnormal
The following terms are widely used to describe cancers according to the origin of the cells that initially became abnormal:
- Carcinoma is a cancer that begins in epithelial cells of tissues that line or cover internal organs or skin. Carcinoma can arise, amongst others, in the breast, colon, liver, lung, prostate or stomach.
- Sarcoma is a cancer that begins in connective tissues cells. Sarcoma can arise, amongst others, in bone, cartilage, fat, muscle or blood vessels.
- Leukemia is a cancer that starts in the bone marrow where blood cells are produced. It is also called blood cancer. In leukemia, no solid tumor is formed but there is a production of a large number of abnormal blood cells, usually white blood cells.
- Lymphoma and myeloma which are cancers that begin in the cells of the immune system.
- Gliomas, neuroblastomas, schwanomas, medulloblastomas which are cancers that begin in the tissues of the brain and spinal cord.
In addition to these terms, the name of the cancer often has a prefix that describes the function or specialization of the cell from where it originated.
• Chondro = cartilage, e.g. a chondrocarcinoma is a cancer in epithelial cells of cartilage
• Erythro = red blood cell, e.g. an erythroblastic sarcoma is a cancer in erythroblasts or cells that form red blood cells, which are connective cells
• Hemangio = blood vessels, e.g. hemangiosarcoma is a cancer in cells that forms in connective cells of blood vessels
• Hepato = liver, e.g. a hepatocarcinoma is a cancer in epithelial cells of the liver
• Lipo = fat, e.g. a liposarcoma is a cancer in fatty cells which are connective cells
• Lympho = lymphocyte, e.g. a lymphosarcoma is a cancer that affects lymphatic cells in lymph nodes and the surrounding connective tissue
• Melano = pigment cell, e.g. a melanoma is a cancer in pigmented cells of the skin
• Myelo = bone marrow, e.g. a myelosarcoma: Cancer in bone marrow which is a type of connective tissue
• Myo = muscle, e.g. a myosarcoma is a cancer in the muscular cells, which are a type of connective cells
• Osteo = bone, e.g. an osteosarcoma is a cancer in bone cells, which are a type of connective cells
Most names of cancers are a combination of the characteristics mentioned before. For instance, a breast cancer is usually an adenocarcinoma of the breast.
But, there are cases where one or several metastases are identified but, the place where the first tumor has initiated cannot be found. This type of cancer is called cancer of unknown primary origin and represents between two to four percent of all cancers. In leukemia and lymphoma, the place of origin cannot be attributed to one specific location because cancer cells are found in different places at the same time but this does not mean that the cancer is metastatic. Rarely, the type of tumor cells is impossible to identify because they have become so different that they lose all characteristics of the tissue they came from. Such a cancer is called an undifferentiated cancer.