The local clinical treatment recommendations regarding NACT for BC patients did not fundamentally change during the study’s time span – taxans (96% of the patients received NACT containing taxans) were used since the beginning of neoadjuvant treatment in Southern part of Sweden and none of the included patients received dual HER2-blockage since their treatment preceded this routine; thus, stratification for time was not warranted. This evidence concerns the gene ERBB2 and breast cancer.