Been through this with my girlfriend who was diagnosed with TNBC in 2015. The second opinion amounted to "guys your doctor is a rock star, there's nothing here that's amiss and you are on a good path". She was cured and remains cancer-free to this day. This doctor had the confidence to say that he would cure it, and as you can imagine myself and my girlfriend were cynical but that's what actually happened. Was round about the time David Bowie died.