In a cohort of breast cancer screened patients the proportion of HER2 positive cases is lower than that earlier reported and pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases.

Human epithelial growth factor receptor 2 (HER2) overexpression and/or amplification is of predictive and prognostic value in infiltrating breast carcinoma (IBC). We evaluated the proportion of HER2-positive cases (score 3 overexpression/score 2 plus fluorescence in situ hybridization (FISH) amplification) in a consecutive series of 2163 patients. According to immunohistochemical analysis of HER2 expression, using Herceptest and FDA criteria, 839 cases had score 0, 476 score 1+, 699 score 2+, and 149 score 3+.

Pharmacogenetic interaction analysis of VEGFR-2 and IL-8 polymorphisms in advanced breast cancer patients treated with paclitaxel and bevacizumab.

Aim: To investigate pharmacogenetic interactions among VEGF-A, VEGFR-2, IL-8, HIF-1α, EPAS-1 and TSP-1 SNPs and their role on progression-free survival in a population of metastatic breast cancer patients treated with bevacizumab in combination with first-line paclitaxel.

Patients & Methods: Analyses were performed on germline DNA obtained from blood samples and SNPs were investigated by real-time polymerase chain reaction technique. The multifactor dimensionality reduction methodology was applied to investigate the interaction between SNPs.

PI3KCA mutation status is of limited prognostic relevance in ER-positive breast cancer patients treated with hormone therapy.

PI3K/AKT/mTOR pathway alterations are frequent in patients with infiltrating breast cancer (IBC). Their clinical and pathological relevance has been insufficiently documented. We evaluated PI3KCA for mutations and the expression of PTEN, AKT, mTOR and p70S6K by immunohistochemistry in 246 IBC patients treated with hormone therapy (median follow-up, 97 months).

PI3KCA mutations and/or PTEN loss in Her2-positive breast carcinomas treated with trastuzumab are not related to resistance to anti-Her2 therapy.

The purpose of this study is to evaluate whether activating mutations of the p110α catalytic subunit of class A phosphoinositide 3-kinases (PI3KCA) or complete loss of phosphatase and tensin homolog (PTEN) is associated with response to anti-human epidermal growth factor receptor 2 (Her2) treatment in breast cancer (BC). We analysed PI3KCA hot-spot mutations and PTEN immunohistochemical expression in 129 Her2-positive infiltrating BC treated with trastuzumab, including 26 cases treated with neoadjuvant therapy, 48 metastatic infiltrating breast cancer (IBC; MBC) and 55 early-stage IBC, with complete clinical information (mean follow-up 37, 66 and 32 months, respectively). PI3KCA hot-spot mutations were observed in 25 cases (19 %): 12 (9 %) in exon 9 and 13 (10 %) in exon 20.