BACKGROUND Early studies have demonstrated comparable levels of HER2/ErbB2 expression in both breast and ovarian cancer. Trastuzumab (Herceptin), a therapeutic monoclonal antibody directed against HER2, is FDA-approved for the treatment of both early and late stage breast cancer. However, clinical studies of trastuzumab in epithelial ovarian cancer (EOC) patients have not met the same level of ...

The benefit of adjuvant trastuzumab in disease-free and overall survival for human epidermal receptor 2-positive (HER2+) breast cancer patients is well established. However, the effect of trastuzumab on locoregional control remains unclear, particularly in patients treated with adjuvant radiotherapy (RT). In this study, we investigated the locoregional benefit of trastuzumab in patients with HE...

BACKGROUND In light of clinical uncertainty and the high acquisition costs of trastuzumab, we examined the value for money associated with concurrent or sequential trastuzumab in women with HER-2/neu-positive breast cancer with small node-negative tumours (T1bN0). MATERIALS AND METHODS A probabilistic economic model was developed to estimate the likelihood of adjuvant trastuzumab meeting a $1...

The antibody trastuzumab is approved for treatment of patients with HER2 (ERBB2)-overexpressing breast cancer. A significant fraction of these tumors are either intrinsically resistant or acquire resistance rendering the drug ineffective. The development of resistance has been attributed to failure of the antibody to inhibit phosphoinositide 3-kinase (PI3K), which is activated by the HER2 netwo...

Autophagy may control the de novo refractoriness of HER2 gene-amplified breast carcinomas to the monoclonal antibody trastuzumab (Herceptin). Tumor cells originally obtained from a patient who rapidly progressed on trastuzumab ab initio display increased cellular levels of the LC3-II protein--a finding that correlates with increased numbers of autophagosomes--and decreased levels of the autopha...

Leptomeningeal carcinomatosis is a fatal manifestation of metastatic breast cancer. Investigation of intrathecal (IT) trastuzumab for leptomeningeal carcinomatosis is currently underway; however, there has been no consensus. We report on two cases of human epidermal growth factor receptor 2 positive (HER2+) breast cancer following IT trastuzumab for leptomeningeal carcinomatosis. The first pati...

Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without tra...

PURPOSE Resistance to anti-HER2 monoclonal antibody trastuzumab is a relevant issue in breast cancer patients. Among the mechanisms implicated in trastuzumab resistance, increasing evidence supports a role of tumor microenvironment. We previously found that a novel toll-like receptor 9 agonist, referred to as immune modulatory oligonucleotide (IMO) and currently under clinical investigation, ac...

Trastuzumab is regarded as the primary therapy for patients with HER2-enriched breast cancer, but the pathological complete response for advanced cases is less than 30%. The underlying mechanism of trastuzumab resistance remains unclear and there are currently no conclusive biomarkers for patient response to trastuzumab. Identifying predictive biomarkers for trastuzumab response may allow treat...

PURPOSE We have previously shown that PTEN loss confers trastuzumab resistance in ErbB2-overexpressing breast cancer using cell culture, xenograft models, and patient samples. This is a critical clinical problem because trastuzumab is used in a variety of therapeutic regimens, and at the current time, there are no established clinical strategies to overcome trastuzumab resistance. Here, we did ...