What are cancer stages and grades?

 Cancer staging is the process of classifying a cancer by the extent of the cancer's spread. The stage of a cancer is based on factors such as the size of the tumor, whether it has invaded nearby tissues or organs, and whether it has metastasized (spread) to other parts of the body.

Cancer grading is a system that assigns a number to reflect how aggressive a tumor appears under a microscope. The lower the grade number, the less aggressive and dangerous the tumor appears to be. Grades range from 1 (least aggressive) to 4 (most aggressive).