In some cases, for example, leukemia, the diagnosis is made from blood. For the diagnosis of most cancers, however, a tissue sample is required. At the time of surgery the surgeon often waits for the diagnosis from the pathologist before deciding how much tumor to remove if any, and what treatment is needed for that patient. The pathologist has a very life-saving position and is often never met by the patient. Cancer is a group of more than 100 different diseases that have some important things in common.
Cancer cells are abnormal and divide without control or order.
These cells can invade and destroy the tissue around them. Cancer cells can also break away from a malignant tumor and enter the bloodstream or lymphatic system. This process, called metastasis, is how cancer spreads from the original tumor to form new tumors in other parts of the body. Names of more common cancers include carcinoma, sarcoma, lymphoma and leukemia. There are some tests that help to locate DNA abnormalities.