Cancer grade and stage

When a cancer is evaluated, two words come up that seem alike but do not mean the same thing: grade and stage. Grade is like a close-up photo of the cells, and stage is like a map of how far the cancer has reached.

Grade is the close-up photo. A pathologist, the doctor who studies tissues, looks at the cancer cells under a microscope and notes how normal or abnormal they look. The higher the grade, the more abnormal the cells look, and the more likely that cancer is to grow and spread quickly.

Stage is the map. It looks not at each cell but at the extent of the cancer: how big the tumor is and whether it has spread. The most widely used system for drawing that map is TNM. T refers to the size and extent of the main tumor; N, to how many nearby lymph nodes, small organs of the immune system found throughout the body, contain cancer; and M, to whether there is metastasis, meaning whether the cancer has already traveled from the main tumor to other parts of the body.