Discussion of the TNT trial was brisk at the 2014 San Antonio Breast Cancer Symposium. George Sledge, MD, Professor of Medicine and Chief of Oncology at Stanford University School of Medicine, Palo Alto, California, called the study “intriguing” and commented: “The platinum results, I believe, are pretty much what most of us would expect, but I am astonished at the response rate to docetaxel [in the non–basal-like subgroup]. This is the highest reported for a taxane in breast cancer.”

Lead author Andrew Tutt, MB, ChB, PhD, MRCP, FRCR, of Kings College and Institute of Cancer Research London, cautioned that this was shown in a small subpopulation that is not yet understood. “We will further analyze the non–basal-like subgroup, try to define how they are made up, and see where this result is coming from,” he said. “One might speculate there is a population within the non–basal-like triple-negative group that has high chemotherapy sensitivity, but we need to understand the biology before concluding too much from this.”

Ann Partridge, MD, Associate Professor of Medicine at Harvard Medical School, who moderated the session, commented for The ASCO Post in an interview and agreed with Dr. Sledge. “The most compelling things in this study are the extraordinary response rate to carboplatin for BRCA1/2 carriers and the very high response to docetaxel in non–basal-like triple-negative breast cancer,” she said. “These are findings that we definitely should look into further.”

“It may be worth pursuing docetaxel in triple-negative breast cancer patients who are non-BRCA carriers. Whether this is true only for docetaxel or other taxanes, we don’t know. But a more than 70% response is astronomical, especially in a previously treated population, the vast majority of whom had had taxanes before,” Dr. Partridge said. 

“The other take-home is that we are still not there yet, beyond BRCA, in determining who is best served by adding a platinum. It doesn’t appear that a platinum is going to be a panacea for triple-negative tumors across the board, though it’s a reasonable drug to try,” she continued. “HRD did not help us predict this, at least in this study. The other thing is that carbo­platin comes with a set of toxicities. Will it really be better than other standard agents? We don’t know yet.” ■

Disclosure: Drs. Sledge and Partridge reported no potential conflicts of interest.