Agree with what’s posted above - no good evidence cutting out anything besides alcohol will affect your chances of recurrence. I’ve been told to eat extra dairy as I have bone thinning caused by my cancer treatment. Countries where people eat a lot of unprocessed soya products usually have lower breast cancer rates.
The Penny Brohn centre run free cancer nutrition courses in person and online that are really informative and evidence-based. I just try to follow their guidelines, which are really just a Mediterranean diet - loads of fruit and veg, pulses, beans and wholegrains, olive oil. I drink kefir and have live yoghurt for the calcium and probiotics.