Grade Definition

Grade: How aggressive a cancer is can be predicted by its grade. To grade cancer, a pathologist examines a biopsied tumor under a high power microscope and notes special characteristics of the cancer cells, which can indicate how aggressively they may behave in future. Sometimes, veterinarians and oncologists use words such as “angry” or “hot,” to describe very aggressive tumors. Different grading systems are used for different tumor types, but generally the more aggressive a tumor is the higher is the number assigned. “High grade” tumors are more aggressive and “low grade” tumors are less so.