By examining the cancerous tissue under a microscope, a pathologist can usually tell whether the type of cell is normally found in the part of the body where the tissue sample was taken. Metastatic cancers may be found at the same time as the primary tumor, or months or years later. When cancer has metastasized, it may be treated with chemotherapy, radiation therapy, biological therapy, surgery, or a combination of these. The choice of treatment generally depends on the type of primary cancer, the size and location of the metastasis, the patient's age and general health, and the types of treatments used previously. New methods of treatment also are under study.
Clinical trials are a critical step in the development of new methods of treatment.
Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is both safe for patients and effective against the disease. Patients interested in participating in research should ask their doctor to find out whether they are eligible for a clinical trial. They can answer questions in English and Spanish and can send free printed material. In addition, CIS offices serve specific geographic areas and have information a bout cancer-related services and resources in their region. This document is also available through the NCI's CancerFax and CancerNet services, and in the News Section of the PDQ database.