When do you offer PMRT for clinical T3N0 breast cancer with a pCR after neoadjuvant chemotherapy?

I think this is a very interesting question, and one about which we have relatively little data. For pathologic T3N0 disease treated with mastectomy, radiotherapy is reasonable (NCCN tells us to "consider RT") but, I believe, falling out of favor. Data from the NSABP suggest that the 10-year risk of LRR after mastectomy in this population is <10% and the EBCTCG fails to find a survival advantage for PMRT in node-negative women. However, other series suggest that the risk of LRR for node-negative...

I think you need to look at the constellation of risk factors in addition to stage. Pathologic complete response in patients with clinical stage II disease is in general associated with a low local recurrence risk and many of these patients can avoid PMRT. However, there are other risk factors for LRR, and relatively few data in the neoadjuvant chemotherapy setting. The MD Anderson series give us a lot of information, but the radiotherapy use was not randomized in those studies. Other important ...