Do the results of the GEPAR trials indicate that PMRT based on pre-neoadjuvant chemo risk factors, irrelevant of pCR, should be the standard of care until NSABP B-51 is completed?

I do not think the GEPAR ASCO 2015 abstract and presentation should be used to conclude that we should recommend PMRT for all node + positive patients regardless of response to preoperative treatment.

There are several reasons for this:

*This is an unplanned analysis of the studies, in which radiation data is missing for 40% of the patients. Radiation treatment was based loosely on clinical criteria but was not standardized in the studies.

*The mastectomy population appears to be more locally advan...

Looking at the GEPAR results, in the mastectomy group about 29 patients had pCR and no RT, and in that group RT didn't make any difference in locoregional relapse free survival. What was interesting was that patients with clinical N-positive disease who converted to ypN0 (about 40 pts in the no RT arm) seem to benefit from PMRT (LRRFS 89% vs. 75%). The part which is not known is how many of these clinical N-positive patients had significant residual disease in the breast, clinical stage III dise...

The German Breast Group has performed a number of large trials comparing different regimens of neoadjuvant chemotherapy (NACT). They presented results from these regarding local-regional recurrence (LRR) in San Antonio in 2015. However, they did not publish these data from the three “GEPAR” trials (GeparTrio, GeparQuattro, and GeparQuinto) until 2019 (Krug et al., PMID 31350646). The 5-year cumulative incidence of LRR for patients who had a pathologic complete response (pCR) was 13.8% in 17 pati...