I have ET with the CALR mutation. My platelets are at 651. I am on only a baby aspirin for now, but I think I will be on Hydrea next month as my count keeps going up. During my last doctor visit I was given a choice to go on the chemo or just take aspirin. My doctor said that either choice would be fine, so I declined the Hydrea, but I am sure I will not be given a choice next visit as I suspect my counts will be higher. I am 74, and have no symptoms except fatigue, which could be due to my age. I found this site to be very helpful, so you might get some of the answers you need here.