TY - JOUR T1 - Correlation of Phosphorylated HER2 with Clinicopathological Characteristics and Efficacy of Trastuzumab Treatment for Breast Cancer JF - Anticancer Research JO - Anticancer Res SP - 2509 LP - 2515 VL - 33 IS - 6 AU - SNJEŽANA RAMIĆ AU - KSENIJA ASIĆ AU - MELITA PERIĆ BALJA AU - FRANE PAIĆ AU - VESNA BENKOVIĆ AU - FABIJAN KNEŽEVIĆ Y1 - 2013/06/01 UR - http://ar.iiarjournals.org/content/33/6/2509.abstract N2 - Aim: To determine the correlation of phosphorylated human epidermal growth factor receptor-2 (pHER2) with clinicopathological characteristics of breast cancer (BC) and patients' response to trastuzumab-based therapy. Patients and Methods: pHER2 was determinated immuno-histochemically in 88 cases of HER2-positive and 50 cases of HER2-negative BC. All patients with HER2-positive BC received trastuzumab-based therapy and 16 of them (18.2%) had disease progression during therapy treatment (i.e. trastuzumab-resistant). Results: pHER2 was predominantly expressed in HER2-positive BC, with 55 cases (62.5%) of tumours expressing pHER2. Six cases of HER2-negative cancer (12.5%) displayed positive expression of pHER2. Expression of pHER2 correlated with younger age of patients and negative oestrogen receptor status. Acquisition of resistance to trastuzumab correlated with negativity for pHER2 (p=0.028). Conclusion: Positive expression of pHER2 may yield additional information regarding the poor prognosis of BC and could be used for pre-selection of patients with HER2-overexpressing BC displaying resistance to trastuzumab treatment. ER -