Should additional molecular testing be performed on triple negative breast cancers up-front to identify potentially targetable mutations (e.g. activating HER2 mutations, homologous recombination repair deficiency assays, etc)?  

My institution does not do this routinely. For metastatic triple negative breast cancer, I try to get them on a clinical trial first line and do any trial specific molecular testing that is required if any. But usually somewhere between 1st line and subsequent lines of standard therapy, I send the t...