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Background. Bones constitute the most frequent localization of distant failure in breast cancer patients. Treatment of bone metastases is virtually palliative, but in a proportion of patients can effectively prolong survival and improve quality of life. Currently, there are no effective strategies to prevent bone dissemination with systemic adjuvant therapies. Thus, better molecular selection and identification of patients who have particularly high risk of skeletal metastases may facilitate designing future clinical trials. In this study we analyzed expression of selected tumor proteins potentially associated with skeletal metastases in breast cancer patients. Patients and methods. The study group included 184 metastatic breast cancer patients; 113 with clinically diagnosed bone metastases and 71 with exclusively other sites of metastases, respectively. In all patients, using tissue microarrays technology, IHC expression of the following proteins was evaluated in the primary tumor: estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), Ki67, cyclooxygenase 2 (COX2), chemokine receptor CXCR4, osteopontin (OPN), calcium sensing receptor (CaSR), cytokeratins 5/6 (CK5/6) and parathyroid hormone-related protein receptor 1 (PTHrPR1). Additionally based on ER/PR, HER2 and Ki67 expression, following molecular breast cancer subtypes were selected: luminal A, luminal B HER2-negative, luminal B HER2-positive, nonluminal HER2-positive and triple negative. Results. Median survival in patients with bone vs. other site of metastases was 56 vs. 37 months respectively (p = 0.0098). ER expression was more common in patients who did, compared with those who did not develop bone metastases (74.% vs. 45% respectively; p = 0.0001), whereas cytoplasmic overexpression of OPN (1.9% vs. 14% respectively; p = 0.002) and PTHrPR1 (16% vs. 34% respectively; p = 0.007) was more common in patients with other sites of metastases. The impact of ER and cytoplasmic OPN expression on the risk of bone dissemination was confirmed in the multivariate analysis (Table 1). Luminal A breast cancer subtype (43% vs. 23% respectively; p = 0.009) and luminal B HER2-positive (16% vs. 4.9%, respectively; p = 0.032) were more common among patients with bone dissemination, whereas triple negative tumors prevailed in patients with other sites of metastases (16% vs. 38%; p = 0.002). Median survival of patients with luminal A subtype was significantly longer than that with remaining subtypes (67 vs. 38 months respectively; p = 0.0004). Conclusions. These results suggest that ER expression and lack of OPN expression are independent factors predicting increased risk of bone dissemination in breast cancer patients. Bone metastases are specifically associated with luminal A and luminal B HER2-positive subtypes. [ABSTRACT FROM AUTHOR]

Background: About 10-30% of breast cancer patients will develop brain metastases. In untreated patients with brain metastases the median survival is 1-2 months, and in those undergoing palliative radiotherapy -- 3-6 months. The mechanism of brain metastases remains largely unknown. The identification of molecular markers might help in selecting high risk patients, and enable active surveillance, prevention and early treatment. The aim of this study was to analyze predictive value of expression of selected tumor proteins for the risk of brain metastases in breast cancer patients. Material and methods: This study included 198 advanced breast cancer patients treated between 2001 and 2007 in 11 oncology centers in Poland, including 96 woman with and 102 without overt brain metastases, respectively. The median age at diagnosis in these two groups was 52 and 60 years, respectively, with 52% and 32% of patients being premenopausal. Stage at diagnosis was similar in both groups and ductal carcinoma was a dominant histological type (76% and 86% of cases, respectively). Immunohistochemistry was performed on formalin-fixed paraffin embedded microarray cores derived from the primary tumor. Expression analysis included ER, PR, HER2, Ki67, CK5/6, EGFR, HER3, CXCR4, RAD51, E-cadherin, and claudin 3 and 4. Cox regression model was used to estimate the relative risk of brain metastases. Results: Expression of HER2, CK5/6, EGFR, RAD51 (both cytoplasmatic and nuclear staining), CXCR4 (cytoplasmatic staining) and Ki67 ≥14%, as well as ER or PR negativity was associated with increased risk of brain metastases in the univariate analysis (Table 1). Of those, Ki67 ≥ 14% (HR 2.76 [95%CI 1.70-4.48]; p < 0.001), cytoplasmatic expression of double strand DNA repair gene RAD51 (HR 1.87 [95%CI 1.14-3.08]; p = 0.014) and ER negativity (HR 1.72 [95%CI 0.36-0.94]; p = 0.029) were found to be significantly related to the risk of brain relapse in the multivariate analysis. Four molecular profiles composed of the latter three markers were created, of which a profile including ER, Ki67 and RAD51 was associated with the highest risk of brain metastases (HR 4.43 [95%CI 2.69-7.27]; p < 0.001). Molecular subtype analysis showed the highest risk of BM in the ER/PR/ HER2-negative (triple negative) subset (HR 1.21 [95%CI 1.11-1.32]; p < 0.001). Conclusion: Expression of proteins related to high tumor proliferation, DNA repair and ER negativity is associated with increased risk of brain metastases in breast cancer patients. [ABSTRACT FROM AUTHOR]

Background: Expression of p95HER2 (p95), a truncated form of HER2 also known as p110 or M611-CTF, is a possible trastuzumab resistance mechanism and has been associated with poor prognosis in trastuzumab-treated HER2-positive metastatic breast cancer (MBC). Previously we reported on optimal clinical cutoffs for quantitative p95 (Clin Cancer Res, 16:4226, 2010) and quantitative HER2 protein expression (H2T) by HERmark® (Cancer, 116:5168, 2010) that defined patient subsets with different progression-free survival (PFS). These cutoffs were confirmed in an independent trastuzumab-treated MBC cohort (ASCO 2011, #586). Here, using individual patient data, we performed an analysis on the combined data set of 243 cases from the discovery and validation cohorts to derive optimal cutoffs for quantitative p95 and H2T. Methods: Both quantitative H2T (HERmark, Monogram Biosciences) and p95 assays employed the VeraTag® method to quantify protein expression in formalin-fixed, paraffin-embedded tumor samples from two cohorts of 101 and 142 cases of trastuzumab-treated MBC with 7.4 and 9.2 months median PFS, respectively. All analyses were stratified by hormone receptor status, tumor grade (3 vs. 1+2) and cohort. H2T measurements were compared to pre -specified cutoffs for HERmark negative (H2T<10.5 Relative Fluorescence/mm² tumor [RF/mm²]) and HERmark positive (H2T>17.8 RF/mm²), derived from the <5th percentile of centrally determined HER2-positives and the >95th percentile of centrally determined HER2-negatives, respectively, within a reference database of 1,090 breast cancer patient samples. Results: Patients classified as HERmark-positive had longer PFS than those classified as HERmark-negative (HR = 0.52; p = 0.0006; medians 10.0 and 5.9 months). The previously determined optimal H2T cutoff of 13.8 RF/mm² in the center of the HERmark-equivocal zone, gave a similar result (HR = 0.54; p = 0.0005). This was close to the optimal cutoff of 12.75 RF/mm² (HR = 0.48; p < 0.0001, unadjusted) for the combined data set. The PFS for the small group of patients in the HERmark-equivocal zone (n = 20) was more similar to the HERmark-negatives (equivocal vs. negative: HR=0.98; p = 0.9) than the HERmark-positives (positive vs. equivocal: HR=0.57; p = 0.057). The pre-specified p95 cutoff at 2.8 RF/mm² separated the 174 HERmark-positive cases into two groups of longer (p95<2.8 RF/mm²) vs. shorter PFS (HR = 1.9; p = 0.0014; medians 13.1 and 7.4 months). Increasing continuous p95 also correlated with shorter PFS (HR = 1.9/log; p = 0.022) in the HERmark-positive subset. An optimal p95 cutoff was identified at 2.7 RF/mm² (HR = 2.0; p = 0.0009, unadjusted), although a slightly higher local HR maximum was found at 1.55 RF/mm² (HR = 2.3; p = 0.0004, unadjusted). Conclusions: HERmark positive and negative categories, defined by analytical comparison with centrally determined HER2 status, were confirmed to have significantly different PFS in trastuzumab-treated MBC patients. The optimal H2T clinical cutoff for this combined analysis was centered in the HERmark analytical equivocal zone. An optimal p95 clinical cutoff of 2.7 RF/mm² derived from this combined analysis was nearly identical to the previously established cutoff of 2.8 RF/mm². [ABSTRACT FROM AUTHOR]