CancerQuest >> Cancer Biology >> Defining Cancer

Types of Cancer

All of our cells have similar structures and share a majority of their functions. Cancers may be categorized based on the functions/locations of the cells from which they originate. The following terms are commonly used to distinguish tumors of different origin.

• Carcinoma- a tumor derived from epithelial cells, those cells that line the surface of our skin and organs. Our digestive tract and airways are also lined with epithelial cells. This is the most common cancer type and represents about 80-90% of all cancer cases reported.
• Sarcoma-a tumor derived from muscle, bone, cartilage, fat or connective tissues.
• Leukemia- a cancer derived from white blood cells or their precursors. The cells that form both white and red blood cells are located in the bone marrow.
• Lymphoma- a cancer of bone marrow derived cells that affects the lymphatic system.
• Myelomas- a cancer involving the white blood cells responsible for the production of antibodies (B lymphocytes or B-cells).