Loss of HER2 positivity and prognosis after neoadjuvant therapy in HER2-positive breast cancer patients

Change in HER2 status after neoadjuvant chemotherapy and the prognostic impact in patients with primary breast cancer

“…Two retrospective studies have assessed the prognostic impact of the change in HER2 status after NAC in patients with primary breast cancer . These studies demonstrated that patients with HER2 loss tended to have a higher risk of recurrence than patients in whom HER2 positivity was maintained.…”

“…Because trastuzumab is used in NAC setting, changes in the HER2 status of surgical specimens have been reported . However, the incidence of HER2 discordance between before (in needle biopsy specimens) and after chemotherapy (in surgical specimens), and the prognostic impact of such discordance remain unclear . In a metastatic setting, Niikura et al demonstrated that patients with discordant HER2 status between primary tumor and metastatic tumor had shorter overall survival than patients with concordant HER2 status (hazard ratio [HR], 0.43; P = 0.003) .…”

HER2 loss in HER2‐positive gastric or gastroesophageal cancer after trastuzumab therapy: Implication for further clinical research

“…Therefore, current practice guidelines recommend that metastatic disease at the first recurrence should be biopsied as a part of a workup for patients with recurrent or stage IV disease, and HER2 status should be reevaluated if it is unknown, negative, or not over‐expressed . Several previous studies showed that chemotherapy with or without anti‐HER2 agents, including trastuzumab, influences HER2 expression . HER‐2 loss may be due to changes of HER2 status during tumor progression, differential effects of treatments on clonal subsets, and heterogeneity of HER2 expression, or even technical errors.…”

“…However, acquired resistance to first‐line trastuzumab‐based treatment might have induced resistance to subsequent anti‐HER2‐based therapies. In breast cancer, the selective pressure of treatments—either trastuzumab‐based or even cytotoxics alone—may preferentially eradicate HER2‐overexpressing cancer clones, while the HER2‐negative ones may emerge and drive tumor progression . This phenomenon may be observed also for gastric cancer, being even more relevant because of its marked heterogeneity.…”

Correlation Between Mammograghic Findings and Clinical/Pathologic Features in Women with Small Invasive Breast Carcinomas

“…Human epidermal growth factor receptor 2 (ErbB-2/HER2), a major player in the breast cancer scenario, which belongs to one of the members of the ErbB family of membrane receptor tyrosine kinases, is low-expression in normal breast tissue while over expression is only present in 20%-30% breast cancer (Victorino et al, 2014). Studies have indicated that a HER2-positive status is one of the most powerful poor prognostic factors (Guarneri et al, 2013). Moreover, no significant correlation was found between mammograghic features and ER/PR/HER2 in the current study.…”