I can help on the PR0. It means progesterone isn’t a factor in your breast cancer (PR scores zero), which is strongly oestrogen- and HER receptive. This will direct your team towards specific treatments out of that wide range available for hormone-receptive bc.
Ki-67 is a protein which helps them understand the rate at which a tumour may grow without treatment. You’d need to ask your oncologist to explain your figure as it seems to be borderline.
I can’t help with the grading as my hospital doesn’t use it, as far as I’m aware.
It frustrates me that this information is sent with no explanation as it inevitably leads to worry. The language of cancer, words like invasive and aggressive mean different things to oncologists whereas, to us, they may sound terrifying. In my case, I just ignored all the letters and let them get on with the treatment. The result was that, although I knew I’d had 2 primary tumours, I was never aware that one was triple negative and I had a period of peace of mind once declared NED - until Stage 4 hit me and I learned it was the TN cells that had evaded treatment. I’m kind of grateful for that period of oblivion lol.
You do know you can get quick answers to questions like this by ringing your breast care nurse or by using the support line at the number above. The nurses are very well informed and also very supportive and I can’t recommend them enough. If the nurse hadn’t advised me to ring my own bc nurse about a minor concern I had, I’d be dead by now as no GP ever expected to see breast cancer in an eye socket and I was being written off as having dermatitis over my eyelid!