As a general rule, the grade of a tumor corresponds to its rate of growth or aggressiveness. Poorly differentiated G4 Undifferentiated Although grading is used by pathologists to describe most cancers, it plays a more important role in treatment planning for certain types than for others. An example is the Gleason system that is specific for prostate cancer, which uses grade numbers to describe the degree of differentiation. Lower Gleason scores indicate well-differentiated cells. Intermediate scores denote tumors with moderately differentiated cells.
Higher scores describe poorly differentiated cells.
Grade is also important in some types of brain tumors and soft tissue sarcomas. The CIS, a program of the National Cancer Institute, is a nationwide telephone service for cancer patients and their families, the public, and health care professionals. 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 about cancer-related services and resources in their region.