I was actually in the category for chemo from the Predict Breast model which showed 6% benefit over 10 years (so 6 women out of 100 will be alive at 10 years who did chemo relative to those who did not who would not survive with my scores). My hospital said under 3% they don't do chemo due to the risks involved which they calculate are equal to 3% over 10 years - this is things like risks to heart etc but this varies a lot by chemo. Normally 6% was straight onto chemo at my hospital though they said there were trials were 6% wasn't being put on (but suspect this is more about saving money than what is best). 3% to 5% get free oncotype testing on NHS. I was absolutely petrified of chemo and having a breakdown over it and the oncologist agreed to do oncotype at 6% but results came back high risk, chemo strongly advised and this took 3 weeks to get - UK version of test but NHS paid for it. I then decided I would do it and researched type best for heart and found weekly Pax was the best though the worst ones for heart tend not to be used anymore. I did manage to get it down to 4 cycles from 6 so 12 weeklies. My oncologist said that was controversial but some oncologists including her think the small additional benefit from 6 cycles isn't worth the extra side effects / risks. That is case by case though and the key thing in mine was I had surgery first which removed all 3 cancers, and chemo was for if cells had escaped they couldn't see.
I found chemo really awful tbh, not so much physically apart from losing a lot of hair and neuropathy but mentally especially from the steroids, there are more steroids with weekly and they made me incredibly ill. In the end they reduced them. But not every day was bad and it does end, it was 4 months out of my life with gaps for neuropathy. And now I am 2.5 years out with no reoccurrence. The difficult thing is there's no way of knowing if its doing anything with surgery first. I got through it by just viewing it as one day at a time and thinking I could stop at any point but I made it to the end much to the surprise of my oncologist. Its one of the hardest things I've ever done and not something I would be keen to repeat but I had 2 wonderful chemo buddies I paired up with (online) who helped me through and once through it I now feel if I can do that I can do lots of things. The trouble is cancer can come back in 20 plus years and I think this buys more time. Yes was glad just in 1 node though annoyed as 4.5 months earlier had said to first GP who dismissed in and on all scans not in nodes. I also only am given checks by mammo and ultrasound who only found one of the three cancers as follow up which is far from ideal. But lobular normally comes back at 5 years plus and even though if grows as a spiders web so is very hard to tell you have until stage 2 / stage 3 border I now would be more aware. If cold cap is offered to you (wasn't to me) there is a reasonable chance it will help with hair. Other symptoms just tell them and they do their best to control. Worth going to dentist now and getting anything needed done and extra fluoride toothpaste. Radio after was a breeze and hormone tablets have found OK though people vary on those. Surgery I also found OK and I have DIEP on Tuesday and weirdly looking forward to that.
Also got a cleaner once a month in chemo to do house cleans, if you can afford that strongly recommend or a weekly cleaner. Its very hard to get your head round, my head still isn't 100% round it as I can feel the effects every day still, only mildly and not so it impacts my life but I do think on balance it was the right thing to do though of course I may have had no benefit at all from it. I did ask my oncologist if she was in my position what she would do and she said she would do chemo, she was a wise and sensible woman so I trusted her. She also gave me a choice of lots of different chemos, that is unusual but it did help me feel in control though was like choosing between poisons. And in some ways its best to just get on with it asap. Keep a symptom diary as well as that will be a good guide. It does vary how people find it as well. Get a digital thermometer as well and take temp twice a day and call chemo line immediately if issues even in middle of night, that helps avoid the serious reactions. I also took handgel everywhere and stuck to outdoor activities and never got ill. Loads of anti sickness meds so even with a sickness phobia was fine on that, infact I took a lot less than they gave as was so mild. You don't need to get your head round it completely, just need to turn up. I used to wear velvet clothes so I could stroke them and it helped a bit. So sorry you are being recommended this.