@angele2times my Oncotype was elevated which is why I did the chemo. Said it decreased my chance of metastatic disease from 20% to less than 1. Not sure it was the right decision but I did it. Mine was grade 2 IDC, high Ki67, 100% estrogen responsive but lymph nodes were clear (yea) and of course oncotype positive. My oncologist uses the ca 27-29 as a tumor marker. Initially at 92 (normal is less than 37). Went down to 69 post treatment and stuck there. Then when I started ai, it started back up to 87 when he did pet scan and brain mri (both negative). Then suddenly 1 month later, went back to 69, then 59 then to 52 and stayed in the 50s for 9 months. He wasn’t concerned because it was stable. Went to 6 month recheck and it went back up to 90. Gave it 6 weeks and stayed there so redid the tests and still no areas of interest but test is till in the 80s. So I’m back to 6 week bloodwork and rechecks. Been on Anastrazole and had to change to exemestane about 16 months ago but only been off for about 2 weeks and already feel 50% better. I’ve read the same - that letrozole is the worst of the bunch but as I said, not sure I’m comfortable coming off these meds and not much left to try.