However, recent results of the PHERGain trial in early-stage HER2 + BC, showed that ~ 1/3 of patients with HER2 + BC treated with neoadjuvant trastuzumab and pertuzumab might be spared chemotherapy, thanks to the degree of metabolic response detected with FDG-PET/CT after just 2 cycles of the anti-HER2 combination and subsequent type of pathologic response detected after surgery51. Here, ERBB2 is linked to breast cancer.