Cancers can be grouped according to the type of cell they start in. There are 5 main categories
- Carcinoma – cancer that begins in the skin or in tissues that line or cover internal organs. There are a number of subtypes, including adenocarcinoma, basal cell carcinoma, squamous cell carcinoma, and transitional cell carcinoma
- Sarcoma – cancer that begins in the connective or supportive tissues such as bone, cartilage, fat, muscle, or blood vessels
- Leukaemia – cancer that starts in blood forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and go into the blood
- Lymphoma and myeloma – cancers that begin in the cells of the immune system
- Brain and spinal cord cancers – these are known as central nervous system cancers
Cancers can also be classified according to where they start in the body, such as breast cancer or lung cancer.