I'm not sure but all I can say is that they told me my cancer was grade 3, poorly differentiated. They said this was the most agressive type of breast cancer but also the one that responed best to chemotherapy. This proved to be the case and all my cancer had disappeared before I finished chemo and everything I do now is just to enure it stays gone. It may not be the same thing.

Thank You for your reply!

Your query got me wondering - so I've done a bit of Googling and this is the best explanation I could find. I hope it helps. "In biology, (differentiation) describes the processes by which immature cells become mature cells with specific functions. In cancer, this describes how much or how little tumor tissue looks like the normal tissue it came from. Well-differentiated cancer cells look more like normal cells and tend to grow and spread more slowly than poorly differentiated or undifferentiated cancer cells. Differentiation is used in tumor grading systems, which are different for each type of cancer."

www.cancer.gov/.../cancer-terms