OW 1223 Street Ave. Normal cells have a characteristic shape and size, and they grow and divide according to a well-ordered schedule. The schedule of growth and division is determined by signals that cells receive from neighboring cells and tissues. But cancer cells lose their characteristic shape and size and they divide uncontrollably. This results in the development of a mass called a tumor which can damage neighboring tissues.
Many tumors are malignant .
This means that they can spread and cause death. The process of invasion is called metastasis . There are different classes of cancer. A sarcoma originates in cells from deeper tissues such as bone or muscle. Different kinds of cancer have different names, depending on the tissue of origin.