tests for tnbc reocurrence

just wondering ,for hormone positive breast cancer,people have oncotyping to see what their reoccurrance rate would be. What have we got? my MO told me I had a 40% chance of reocurrence but could knock to half if I had chemo. I was wondering how he came up with that. I had abmx and had a 1.8 cm idc with 0/7 lymph nodes they said it was early stage stage 1 grade 3 . So what would put me in that high probability for reocurrence?versus somebody else with the same dx?would the fact that its my 2nd bc after almost 14 years (1st was hormone positive) could it be 3 sisters including me had bc,or that all of us in the family have the BRCA1 gene.Or could it be that it was "worrysome" for my mo that there was no cancer when ultrasound was done after abnormal MRI and it was a cyst but 5 months later there was a lump which my oncologist felt i hr after NORMAL mamogram at the cancer clinic.The mo di say that it was worrisome cuz nothing showed up. But speaking to my surgeon 2 days later ,he said there were things in my path report that he would have prefered not to have in there but I had clear nodes and it was early stage  and he believes that the cancer had not been there and it was new. Is this how they all determine recurrence rates?