Dear Belleview Teacher: No, not necessarily. Some tumors begin as high grade tumors.
I often wonder what the difference is in GRADE and STAGE.
Here's hoping that Cleaveland or "Surgeon" will explain this.
Grade refers how tumor cells look under the microscope. There are various criteria by which grade is measured, and it's somewhat subjective. It includes how much different from normal they look, how many are dividing, etc. Stage refers to the tumor itself, rather than the cells, and has to do with tumor size, lymph node involvement, spread to distant organs, etc. Of the two, stage is probably more important in that it says what the tumor is actually doing. How cells look is somewhat correlated with behavior, but not as directly nor as objectively. As to whether cells change grade as the tumor lives on is a good question, to which I'm not sure there's a known answer. It's certainly known that tumors change behavior over time: one might sit there dormant for years, and then grow like wildfire. I'd assume the wildfire cells look more ugly than the dormant ones. But I'm not aware of studies that have compared the appearance of cells of a particular tumor over time.