Cancer

Cancer refers to a malignant process of the growth of a certain type of cells in vertebrates: epithelial cells. Although this is the technical description, the word is often used, even by physicians, to include all the diseases caused by malignant tumors and cells. For example, malignant tumors called sarcomas arise from abnormal muscle cells, and these are derived from mesothelium rather than from epithelium. Still, Cancer Centers and specialists include treatment of sarcoma in practice, despite the fact that these tumors are not strictly cancers as far as medical terminology of tumors go.