49 malt but I'm pretty sure it's pathology rather than age dictating treatment - including tamoxifen, the pathology then related to your stage of menopause (pre or post).
I was told pre-op, I may or may not have to have chemo, it would depend on the surgery pathology. They were able to get a very clear margin and remove all the tumour and then some. My tumour was also pretty pathetic - grade 1, stage 1, ER+, and very slow growth rate - piss poor really. It doesn't preclude the cancer having spread to other parts of my body, it could be lurking, but hopefully not. It's really a judgement call based on the best possible advice at the time. Hopefully the tamoxifen will stop any any itinerant cells from misbehaving.
And malt I realise you are very anxious about it all, but remember cancer is a disease, it doesn't define you as a person. I feel like a freak with my one real breast, and one pretend breast, my libido seems to have flattened with tamoxifen (should I visit the disney shaggin waggin copt), but I'm much more than that. It's was a very small part of me, well 1.9cm to be precise. Day to day, I'm much more worried about the size of my bottom (vain emoticon!) and what on earth to cook for dinner!