Would you consider treating the regional nodes in addition to the breast in a patient with skin involvement (pT4b) after a lumpectomy with negative margins/nodes who refuses chemotherapy?   

I can't say that this is a commonly encountered scenario.  It's tough to imagine the T4 patients that's a good upfront BCT candidate.  In my opinion, it is very reasonable to consider RNI in a high risk node negative patient.  High risk N0 patients were included in MA.20 and EORTC 229...

Absolutely.  The PMRT trials included T3N0 patients (Overgaard), and that subgroup had the same benefit as the node positive group (especially in the younger pre-men patients).  Also, there is a PMRT study from Helsinki that included node neg cases that also showed a benefit of RT, but the...