According to the National Cancer Institute (NCI), there are more than 100 different types of cancer. Cancers are categorized by the organ involved and the type of cell that gave rise to the cancer. The four overarching groups of cancerous tumors are carcinomas, sarcomas, central nervous system cancers, lymphomas and myelomas. Carcinomas are the most common kind of cancerous tumor.
Carcinomas
Carcinomas arise from epithelial cells that have undergone a cancerous transformation. Epithelial cells cover internal and external body surfaces and line internal organs. Examples of epithelial cells include the skin, the lining of the nose, mouth and airways, the inner surface of the stomach and intestines, the lining of the abdominal cavity and glands cells. Carcinomas that arise from glandular epithelial cells are called adenocarcinomas. The overwhelming majority of human cancers are carcinomas. The most common cancers in the U.S.--skin, lung, breast, prostate and colorectal cancers--are nearly always carcinomas.
Sarcomas
Sarcomas arise from structural tissues such as muscle, cartilage, bone, blood vessels and fat. The word sarcoma comes from a Greek word that means fleshy or meaty, which might help you remember this kind of cancer. Examples of sarcomas include Ewing sarcoma and osteosarcoma (bone cancers), rhabdomyosarcoma and leiomyosarcoma (muscle cancers) and liposarcoma (cancer arising from fatty tissue). Bone sarcomas occur almost exclusively in children and teenagers. Other sarcomas occur in children and adults. NCI estimates that more than 13,000 Americans were diagnosed with sarcomas in 2009.
Central Nervous System Cancers
Central nervous system (CNS) cancers arise from the specialized tissues of the brain or spinal cord. The majority of these cancers occur in the brain or its support tissues. Glioblastomas and meningiomas are the most common CNS tumors in adults. Astrocytomas and embryonal tumors are most common in children. The American Cancer Society estimates more than 22,000 new cases of brain and nervous system cancer were diagnosed in the U.S. in 2009.
Lymphomas and Myelomas
Lymphomas and myelomas arise from immune cells, primarily lymphocytes. Lymphomas occur in both children and adults. Common childhood lymphomas include Burkitt's lymphoma, lymphoblastic lymphoma and large cell lymphoma. Common adult lymphomas include large B-cell lymphoma and follicular lymphoma. Multiple myeloma is a cancer of the antibody-producing cells of the immune system. This cancer is seen almost exclusively in adults, and incidence increases with age. The American Cancer Society estimates more than 95,000 Americans received a cancer diagnosis of lymphoma or myeloma in 2009.
References
- National Cancer Institute: Defining Cancers
- National Cancer Institute: Cellular Classification of Non-Small Cell Lung Cancer
- National Cancer Institute: Cellular Classification of Small Cell Lung Cancer
- National Cancer Institute: General Information about Breast Cancer
- National Cancer Institute: Colon Cancer Cellular Classification
