chemo or no with micro metastasis

If you have any doubts, seek a second opinion but bear in mind it’s a qualified, experienced opinion, not gospel. Every medical practitioner relies on both training and experience and neither will be exactly the same. I had a mastectomy with one clearly malignant lymph node, my cancer was also hormone positive. My surgeon said maybe no chemo but that’s up to your oncologist. My oncologist (and yes, the two work together a lot) was in no doubt about recommending chemo (6 months). My choice, of course, and very few treatments are identical, but like @arpie, the ‘small percentage’ of benefit does matter depending on what side of the ledger you are on! A second opinion may settle your uncertainties. Best wishes.