I have et with jak2 mutation. what should i be concerned about and is it cancer? my hemo says no but others say yes??

ET is a pre-cancer: ET is a chronic disease which can be treated well for many years. Although it is not a true cancer to start with, but it can change into a cancer after 10-15 years. So it is best called a precancerous condition. So what your doctors have told you is largely correct. I expect you to feel well and function like a normal healthy person. I hope this helps!

By definition: All monoclonal overgrowths of blood cells are cancer by definition, since they spread and invade -- that's what blood does. This being said, essential thrombocythemia is as tame a cancer as one can have, and last I heard, doesn't even shorten life expectancy. Keep an eye on it.