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Purpose: Treatment for HER2-low [defined as ImmunoHistoChemistry (IHC) 1 + or 2 + and negative/normal in Situ Hybridization (ISH)] breast cancer patients is rapidly evolving, yet we lack critical information about the HER2-low population., Methods: We conducted a retrospective cohort study of women aged 18 years or older diagnosed with breast cancer between 2010 and 2016 in North Carolina. Analyses were conducted for the overall cohort and a stage IV sub-cohort. We examined demographic and clinical characteristics, and characterized prevalence of HER2-low disease and healthcare utilization. We estimated adjusted rate ratios for the association between HER2 classifications and utilization outcomes, and hazard ratios for 3-year all cause mortality (stage IV only)., Results: The overall and stage IV cohorts included 12,965 and 635 patients, respectively. HER2-low patients represented more than half of both cohorts (59% overall, 53% stage IV). HER2-low patients were more likely than IHC 0 patients to have hormone receptor (HR)-positive disease. In the stage IV cohort, HER2-low patients were more likely to be Black (26% vs. 16% IHC 0, p = 0.0159). In both cohorts, rates of hospitalizations were slightly higher among HER2-low patients. There were no survival differences between HER2-low and IHC 0 among stage IV patients., Conclusion: New treatment options for HER2-low breast cancer may have potential for significant impact at the population level particularly for patients with stage IV disease. In light of racial differences between HER2-low and IHC 0 patients observed in our cohort, research- and practice-based efforts to ensure equitable adoption of new treatment guidelines for patients with HER2-low metastatic breast cancer will be essential., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Multi-gene expression assays have been developed with the aim of predicting late recurrence in patients with estrogen receptor (ER)-positive breast cancer. However, establishment of alternative markers based on immunohistochemistry is also important for achieving practical use. Based on our previous study, forkhead box A1 (FOXA1) protein was tested as a potentially useful predictive marker for late recurrence., Methods: 117 patients with ER-positive HER2-negative invasive breast cancer who developed distant metastasis following curative surgery were retrospectively investigated. We also evaluated responsiveness to endocrine therapy according to FOXA1 expression. Furthermore, publicly available mRNA microarray data were analyzed to examine patterns of metastasis according to FOXA1 mRNA expression, employing the Kaplan-Meier plotter., Results: High expression of FOXA1 was an independent factor predicting long disease-free survival (DFS), along with small tumor size (p = 0.010 and 0.016, respectively). Discrimination of DFS was improved by combining these two factors, i.e., patients with FOXA1-high small tumors had the longest DFS while those with FOXA1-low large tumors had the shortest DFS. Moreover, we revealed that risk of distant metastasis started to increase after the completion of adjuvant endocrine therapy in patients with FOXA1-high tumors., Conclusion: Among patients who developed distant metastasis, those with FOXA1-high tumors had significantly longer DFS. We believe our data to raise the possibility of FOXA1 being a useful predictive marker for late recurrence and to provide new insights into the biology of FOXA1-high breast cancers.

Purpose: Anti-human epidermal growth factor receptor 2 (HER2) therapies are associated with interstitial lung disease (ILD), also referred to as pneumonitis. In this literature review, we describe the incidence of ILD among patients with HER2-positive metastatic breast cancer (MBC) receiving anti-HER2 therapies, and we describe existing recommendations for monitoring and managing drug-induced ILD among these patients., Methods: We searched PubMed and Embase to identify clinical trials and postmarket observational studies that investigated anti-HER2 therapies for HER2-positive MBC, reported on ILD, and were published during January 1, 2009 to July 15, 2019. Articles were screened by two researchers; data were extracted from the full-text articles., Results: The 18 articles selected for this review assessed 9,886 patients who received trastuzumab (8 articles), lapatinib (4 articles), trastuzumab emtansine (3 articles), trastuzumab deruxtecan (2 articles), or trastuzumab duocarmazine (1 article). The overall incidence of all-grade ILD was 2.4% (n = 234), with 66.7% (n = 156) occurring as grade 1-2 events, 0.5% grade 3-4 (n = 54; incidence), and 0.2% grade 5 (n = 16; incidence). The highest ILD incidence (21.4%) was among patients receiving trastuzumab combined with everolimus and paclitaxel. Ten studies indicated that ILD events were managed via dose interruption, dose reduction, or treatment discontinuation; two studies included detailed guidelines on managing drug-induced ILD., Conclusions: ILD is a well-described adverse drug reaction associated with several anti-HER2 drugs. Published ILD management guidelines are available for few anti-HER2 treatment regimens; however, guidance for monitoring for anti-HER2 drug-induced ILD is lacking.

Objectives: The NR5A2 and RYR2 genes are important players in steroid metabolism and play an important role in cancer research. In this research, we want to evaluate the effect of NR5A2 and RYR2 polymorphisms on breast cancer (BC)., Methods: Four single nucleotide polymorphisms on NR5A2 and RYR2 were selected to genotype by Agena MassARRAY in 379 BC patients and 407 healthy controls. Using the PLINK software to calculate the Odds ratio (OR) and 95% confidence intervals (CIs) via the logistic regression analysis to evaluate the risk for BC., Results: We found that NR5A2 rs2246209 significantly decreased the risk of BC with the AA genotype (OR 0.58, 95%CI 0.34-0.99, p = 0.049), and recessive model (OR 0.59, 95%CI 0.35-0.99, p = 0.046); rs12594 in the RYR2 gene significantly decreased the risk of BC in the GG genotype (OR 0.44, 95%CI 0.22-0.88, p = 0.020), and recessive model (OR 0.43, 95%CI 0.21-0.85, p = 0.016). Further stratification analysis showed that NR5A2 rs2246209 was related to a lower incidence of BC affected by age, lymph nodes metastasis, and tumor stage; RYR2 rs12594 was related to a decreased BC risk restricted by age, estrogen receptor (ER), progesterone receptor (PR), menopausal status, tumor size, and tumor stage. Rs12594 in the RyR2 gene remained significant on the genetic susceptibility of PR-positive BC after Bonferroni correction (p < 0.0125)., Conclusions: This study provides an evidence that NR5A2 rs2246209 and RYR2 rs12594 decreased the risk of breast cancer.

Background: The estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) statuses are frequently discordant between the primary tumor and metastatic lesions in metastatic breast cancer. This can have important therapeutic implications., Patients and Methods: In all, 541 patients with available receptor statuses from both primary tumor and metastatic lesion treated at Heidelberg and Tuebingen University Hospitals between 1982 and 2018 were included., Results: Statistically significant discordance rates of 14% and 32% were found for ER and PR. HER2 status was statistically insignificantly discordant in 15% of patients. Gain in HER2 positivity was associated with an improved overall survival, whereas loss of HR positivity was associated with worse overall survival. Antiendocrine treatment differed in 20% of cases before and after biopsy and HER2-directed treatment in 14% of cases., Conclusions: Receptor statuses are discordant between primary tumor and metastasis in a considerable fraction of patients with metastatic breast cancer. Next to a highly presumed predictive value with respect to efficacy of endocrine and HER2-targeted therapy, discordance seems to provide prognostically relevant information. Where feasible, metastatic lesions should be biopsied in accordance with current guidelines.

Purpose: The proliferation-associated biomarker Ki67 has potential utility in breast cancer, including aiding decisions based on prognosis, but has unacceptable inter- and intralaboratory variability. The aim of this study was to compare the prognostic potential for Ki67 hot spot scoring and global scoring using different digital image analysis (DIA) platforms., Methods: An ER+/HER2- breast cancer cohort (n = 139) with whole slide images of sequential sections stained for hematoxylin-eosin, pancytokeratin and Ki67, was analyzed using two DIA platforms. For hot spot analysis virtual dual staining was applied, aligning pancytokeratin and Ki67 images and 22 hot spot algorithms with different features were designed. For global Ki67 scoring an automated QuPath algorithm was applied on Ki67-stained whole slide images. Clinicopathological data included overall survival (OS) and recurrence-free survival (RFS) along with PAM50 molecular subtypes., Results: We show significant variations in Ki67 hot spot scoring depending on number of included tumor cells, hot spot size, shape and location. The higher the number of scored tumor cells, the higher the reproducibility of Ki67 proliferation values. Hot spot scoring had greater prognostic potential for RFS in high versus low Ki67 subgroups (hazard ratio (HR) 6.88, CI 2.07-22.87, p = 0.002), compared to global scoring (HR 3.13, CI 1.41-6.96, p = 0.005). Regarding OS, global scoring (HR 7.46, CI 2.46-22.58, p < 0.001) was slightly better than hot spot scoring (HR 6.93, CI 1.61-29.91, p = 0.009). In adjusted multivariate analysis, only global scoring was an independent prognostic marker for both RFS and OS. In addition, global Ki67-based surrogate subtypes reached higher concordance with PAM50 molecular subtype for luminal A and B tumors (66.3% concordance rate, κ = 0.345), than using hot spot scoring (55.8% concordance rate, κ = 0.250)., Conclusions: We conclude that the automated global Ki67 scoring is feasible and shows clinical validity, which, however, needs to be confirmed in a larger cohort before clinical implementation.

Purpose: This study aimed to develop mathematical tools to predict the likelihood of recurrence after neoadjuvant chemotherapy (NAC) plus trastuzumab in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer., Methods: Data of 776 patients from a multicenter retrospective cohort study were collected. All patients had HER2-positive breast cancer and received NAC plus trastuzumab between 2001 and 2010. Two mathematical tools using a machine learning method were developed to predict the likelihood of disease-free survival (DFS) (DFS model) and brain metastasis (BM) (BM model) within 5 years after surgery. For validation, bootstrap analyses were conducted. The area under the receiver operating characteristics curve (AUC) was calculated to examine the discrimination., Results: The AUC values were 0.785 (95% CI 0.740-0.831, P < 0.001) for the DFS model and 0.871 (95% CI 0.830-0.912, P < 0.001) for the BM model. Patients with low-risk DFS or BM events, as predicted by the models, showed better 5-year DFS and BM rates than those with high-risk DFS or BM events (89% vs. 61% for the DFS model, P < 0.001; 99% vs. 87% for the BM model, P < 0.001). These models maintained discrimination abilities in both luminal and non-luminal subtypes, providing prognostic information independent of pathological response. Bootstrap validation confirmed the high generalization abilities of the models., Conclusions: The DFS and BM models have a high accuracy to predict prognosis among HER2-positive patients treated with NAC plus trastuzumab. Our models can help optimize adjuvant therapy and postoperative surveillance.

Purpose: Based on improvement in pathologic complete response (pCR) in the NeoSphere and TRYPHAENA studies, the FDA approved neoadjuvant pertuzumab for HER2+ localized breast cancer. These studies demonstrated high pCR rates with THP (docetaxel + HP), FEC (5-fluorouracil, epirubicin, and cyclophosphamide)-THP, and TCHP (docetaxel, carboplatin + HP). However, in the United States, doxorubicin/cyclophosphamide (AC) is favored over FEC despite no data comparing neoadjuvant AC-THP with AC-TH or TCHP. Here we report outcomes for patients with localized HER2+ breast cancer treated with pertuzumab-containing neoadjuvant regimens and AC-TH., Methods: We reviewed clinicopathological characteristics of patients with HER2+ breast cancer (Stage I-III) treated with either a neoadjuvant pertuzumab-containing regimen or dose-dense (dd) AC-TH, from 2011 to 2016 at a large academic medical institution and two affiliated community sites. pCR was defined as ypT0/is ypN0. Fisher's exact test and logistic regression analysis were used for statistical analysis., Results: In this study (N = 121), pCR was numerically higher with pertuzumab-based regimens, including ddAC-THP (60%), TCHP (63%), THP (55%), as compared with ddAC-TH (46%). THP resulted in significantly less cycle delays due to toxicity compared to the other regimens (p = 0.02). THP also resulted in the least dose reductions, lowest rate of hospitalization, and lowest rate of treatment discontinuation., Conclusions: Pertuzumab-based regimens, including THP, resulted in higher pCR rates as compared to ddAC-TH, with the THP regimen associated with the best tolerability among patients with localized HER2+ breast cancer. Given the various neoadjuvant regimens, additional studies are needed to determine optimal treatment sequencing and escalation/de-escalation strategies to personalize neoadjuvant regimens for localized HER2+ breast cancer.

Purpose: Although age is a recognized independent prognostic risk factor, its relative importance among molecular subtypes of Breast cancer (BCA) is not well documented. The aim of this study was to evaluate the prognostic role of age at diagnosis among different immunohistochemical subtypes of BCA., Methods: We conducted a retrospective study of women with invasive BCA undergoing surgery at the Johns Hopkins Hospital, excluding patients presenting with stage IV breast cancer. Patients were stratified into three age groups: ≤ 40, 41-60, and > 60 years, and multivariable analysis was performed using Cox regression. We also identified differentially expressed genes (DEG) between age groups among BCA subtypes in the public TCGA dataset. Finally, we identified key driver genes within the DEGs using a weighted gene co-expression network analysis., Results: Luminal A breast cancer patients had significantly lower 5 year disease-free survival (DFS) and distant metastasis-free survival (DMFS) in the ≤ 40 year age group compared to the 41-60 year age group, while the other molecular subtypes showed no significant association of DFS or DMFS with age. Age was a stronger outcome predictor than tumor grade or proliferative index in Luminal A BCA patients, but not other subtypes. BCA TCGA gene expression data were divided into two groups (≤ 40 years, > 40 years). We identified 374 DEGs in the Luminal A BCA subset, which were enriched in seven pathways and two modules of co-expressed genes. No age group-specific DEGs were identified in non-Luminal A subtypes., Conclusions: Age at diagnosis may be an important prognostic factor in Luminal A BCA.

Background/purpose: The 21-gene recurrence score (RS) assay predicts the likelihood of distant recurrence and chemotherapy benefit in early-stage, estrogen receptor (ER)-positive, HER2-negative breast cancer. Data on the RS of special histologic subtypes of invasive breast carcinoma with favorable prognosis are limited., Methods: We reviewed our institutional database to identify patients with special histologic subtypes of breast cancer associated with favorable prognosis and available RS results. Our cohort consists of fifty-seven women: thirty-three patients with pure mucinous carcinoma (MC), ten with tubular carcinoma (TC), nine with encapsulated papillary carcinoma (EPC), and five with solid papillary carcinoma (SPC)., Results: Most (44/57, 77.2%) carcinomas had low RS (≤17), and none had high RS (≥31). All EPCs had low RS, but other subtypes had RS 18-30. Higher RS was associated with lower progesterone receptor (PR) expression by immunohistochemistry and lower PR mRNA scores (P ≤ 0.007). No morphologic feature (tumor grade, biopsy site changes, cellular stroma, inflammatory cells) was associated with RS ≥ 18. At a median follow-up of 40 months, the distant recurrence-free survival was 100%. One patient with SPC developed locoregional recurrence at 22 months., Conclusions: As the largest series to date, our study raises the question of whether the RS assay is necessary for breast cancers with favorable histology. Reflex testing of node-negative, ER+/HER2- breast cancers may be deferred for these special histologic subtypes, emphasizing the need for multidisciplinary discussions between breast pathologists and other members of the breast cancer team.

The effect of race on breast cancer outcome is confounded by tumor and treatment heterogeneity. We examined a cohort of women with stage II-III breast cancer treated uniformly with neoadjuvant chemotherapy to identify factors associated with racial differences in chemotherapeutic response and long-term survival. Using a prospective database, we identified women with stage II-III breast cancer treated with neoadjuvant chemotherapy from 1998 to 2011. Race was categorized as African-American (AA) or non-AA. Preplanned subtype analyses were stratified by hormone receptor (HR) and HER2. Pathologic response to chemotherapy (pCR), time to recurrence (TTR), and overall survival (OS) were assessed using logistic regression, Kaplan-Meier method, and Cox proportional hazards regression analyses. Of 349 women identified, 102 (29 %) were AA, who were younger (p = 0.03), more obese (p < 0.001), and less likely to have HR+/HER2- tumors (p = 0.01). No significant differences in pCR rate by race were found. At median follow-up of 6.5 years, AA had worse TTR (hazard ratio 1.51, 95 % CI 1.02-2.24), which was attenuated in multivariable modeling, and there was no significant difference in OS. When stratified by HR, worse outcomes were limited to HR+AA (TTR hazard ratio 1.85, 95 % CI 1.09-3.14; OS hazard ratio 2.42 95 % CI 1.37-4.28), which remained significant in multivariable analysis including pCR rate and BMI. With long-term follow-up, racial disparity in outcome was limited to HR+ breast cancer, with no apparent contribution of chemotherapy sensitivity. This suggests that disparity root causes may be driven by HR+ factors such as unmeasured molecular differences, endocrine therapy sensitivity, or adherence.

African American (AA) women are more likely than white women to be obese and to be diagnosed with ER- and triple-negative (TN) breast cancer, but few studies have evaluated the impact of obesity and body fat distribution on breast cancer subtypes in AA women. We evaluated these associations in the AMBER Consortium by pooling data from four large studies. Cases were categorized according to hormone receptor status as ER+, ER-, and TN (ER-, PR-, and HER2-) based on pathology data. A total of 2104 ER+ cases, 1070 ER- cases (including 491 TN cases), and 12,060 controls were included. Odds ratios (OR) and 95 % confidence intervals (CI) were computed using logistic regression, taking into account breast cancer risk factors. In postmenopausal women, higher recent (most proximal value to diagnosis/index date) BMI was associated with increased risk of ER+ cancer (OR 1.31; 95 % CI 1.02-1.67 for BMI ≥ 35 vs. <25 kg/m(2)) and with decreased risk of TN tumors (OR 0.60; 95 % CI 0.39-0.93 for BMI ≥ 35 vs. <25). High young adult BMI was associated with decreased premenopausal ER+ cancer and all subtypes of postmenopausal cancer, and high recent waist-to-hip ratio with increased risk of premenopausal ER+ tumors (OR 1.35; 95 % CI 1.01-1.80) and all tumor subtypes combined in postmenopausal women (OR 1.26; 95 % CI 1.02-1.56). The impact of general and central obesity varies by menopausal status and hormone receptor subtype in AA women. Our findings imply different mechanisms for associations of adiposity with TN and ER+ breast cancers.

Epithelial mesenchymal transition (EMT), as defined by loss of epithelial characteristics and gain of a mesenchymal phenotype, has been reported in vivo although the occurrence of events remains unclear. This study aims at exploration of EMT portraits of breast cancer (BC) with relevance to different molecular pathways, especially potential EMT triggers and BC molecular subtypes. Immunohistochemical (IHC) expression of markers/triggers of EMT was studied on a well-defined cohort of invasive non-lobular BC (n = 1,035), prepared as tissue microarrays. IHC panel of biomarkers included cadherins (cad; E-cad and N-cad), TGFβ1, PIK3CA, pAkt, and others. Reverse phase protein array (RPPA) was performed for quantitative analysis of proteins extracted from formalin fixed paraffin embedded tissues of a subset of cases from this cohort. Four combinatorial phenotypic groups representing cadherin switch were defined, including E-cad(+)/N-cad(-), E-cad(-)/N-cad(-), E-cad(+)/N-cad(+), and E-cad(-)/N-cad(+). Statistically significant association was noticed between these phenotypes and histological tumour grade, tumour type and size and NPI staging classes. The E-cad/N-cad switch occurred more frequently in the triple negative molecular class, both basal and non-basal, and in the HER2(+) subtype than in luminal BC. Significant outcome differences were observed between cadherin switch combinatorial groups regarding BCSS and DMFS (p < 0.001). Results of RPPA confirm those observed using IHC regarding differential expressions of EMT markers/triggers. EMT/cadherin switch programs in BC appear to occur in synergy with TGFβ1 and PIK3/Akt pathways activation. These data explain, at translational proteomic level, the molecular heterogeneity and in turn the varied clinical behaviour of BC molecular subtypes. RPPA is a promising high-throughput technique in monitoring subtle quantitative changes in protein expression in archival material.

NSABP B-43 is the first prospective, randomized phase III multi-institution clinical trial targeting high-risk, HER2-positive DCIS. It compares whole breast irradiation alone with WBI given concurrently with trastuzumab in women with HER2-positive DCIS treated by lumpectomy. The primary aim is to determine if trastuzumab plus radiation will reduce in-breast tumor recurrence. HER2-positive DCIS was previously estimated at >50 %, occurring primarily in ER-negative, comedo-type DCIS of high nuclear grade. There has been no documented centralized multi-institutional HER2 analysis of DCIS. NSABP B-43 provides a unique opportunity to evaluate this in a large cohort of DCIS patients. Patients undergoing lumpectomy for DCIS without evidence of an invasive component are eligible. A central review of each patient's pure DCIS lesion is carried out by immunohistochemistry analysis. If the lesion is 2+, FISH analysis is performed. Patients whose tumors are HER2 3+ or FISH-positive are randomly assigned to receive two doses of trastuzumab during WBI or WBI alone. NSABP B-43 opened 11/9/08. As of 7/31/2013, 5,861 patients have had specimens received centrally, and 5,645 of those had analyzable blocks; 1,969 (34.9 %) were HER2 positive. A total of 1,428 patients have been accrued, 1,137 (79.6 %) of whom have follow-up information. The average follow-up time for the 1,137 patients is 23.3 months. No grade 4 or 5 toxicity has been observed. In NSABP B-43 the HER2-positive rate for pure DCIS among patients undergoing breast-preserving surgery is 34.9 %, lower than the previously reported rate. No trastuzumab-related safety signals have been observed. Interest in this trial has been robust.

Clinical trials have shown the efficacy of trastuzumab-based adjuvant therapy in HER2-positive breast cancers, but routine clinical use awaits evaluation of compliance, safety, and effectiveness. Adjuvant trastuzumab-based therapy in routine clinical use was evaluated in the retrospective study GHEA, recording 1,002 patients treated according to the HERA protocol between March 2005 and December 2009 in 42 Italian oncology departments; 874 (87.23 %) patients completed 1-year trastuzumab treatment. In 128 patients (12.77 %), trastuzumab was withdrawn due to cardiac or non-cardiac toxicity (28 and 29 patients, respectively), disease progression (5 patients) or the clinician's decision (66 patients). In addition, 156 patients experienced minor non-cardiac toxicities; 10 and 44 patients showed CHF and decreased LVEF, respectively, at the end of treatment. Compliance and safety of adjuvant trastuzumab-based therapy in Italian hospitals were high and close to those reported in the HERA trial. With a median follow-up of 32 months, 107 breast cancer relapses were recorded (overall frequency, 10.67 %), and lymph node involvement, estrogen receptor negativity, lymphoid infiltration, and vascular invasion were identified as independent prognostic factors for tumor recurrence, indicating that relapses were associated with advanced tumor stage. Analysis of site and frequency of distant metastases showed that bone metastases were significantly more frequent during or immediately after trastuzumab (<18 months from the start of treatment) compared to recurrences in bone after the end of treatment and wash-out of the drug (>18 months from the start of treatment) (35.89 vs. 14.28 %, p = 0.0240); no significant differences were observed in recurrences in the other recorded body sites, raising the possibility that the protection exerted by trastuzumab is lower in bone metastases.

The heterogeneity of breast cancer makes its diagnosis and treatment far from being optimal. Analysis of traditional pathological and prognostic markers based on immunohistochemistry (IHC) is inadequate in elucidating the inherent heterogeneity of breast cancer, especially basal-like breast carcinoma (BLBC) which displays complex and unique epidemiological, phenotypic, and molecular features with distinctive relapse patterns and poor clinical outcomes. Gene expression profiling opened an avenue in research as independent predictors by classifying breast cancers into discrete groups with prognostic references, but it is not cost-effective in clinical application. It is necessary to develop an effective predictive gene list from gene profiling to optimize the treatment with traditional markers. In this report, we analyzed the correlation between IHC and gene profiling of breast cancer with an emphasis on the BLBC, highlighting the potential discovery of diagnostic markers and cellular mechanisms that may guide the development of BLBC-targeted therapy. Random forest-based classification and PAM50 gene-sets were used in the comparison analysis of traditional prognostic markers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and microarray profiles. An intrinsic 40-gene set was developed to classify breast cancer subtypes, and genes expression differentiations were used to explore the different mechanisms between the BLBC and non-BLBC subtypes based on the comparison of clinicopathological markers and microarray profiling. Pathways and DNA repairs were analyzed to evaluate the biological mechanisms in BLBC and other breast cancer subtypes. It is reasonable to define BLBC as those tumors that are negative for ER, PR, and HER2 by IHC for their accordance with gene expression profiles. Focal adhesion kinase, ERBB, and their signaling pathways may play crucial role in BLBC. The intrinsic 40-gene set can be used to classify breast cancer and help to optimize therapeutic management of BLBC.

Trastuzumab is effective in the treatment of HER2/neu over-expressing breast cancer, but not all patients benefit from it. In vitro data suggest a role for HER3 in the initiation of signaling activity involving the AKT–mTOR pathway leading to trastuzumab insensitivity. We sought to investigate the potential of HER3 alone and in the context of p95HER2 (p95), a trastuzumab resistance marker, as biomarkers of trastuzumab escape. Using the VeraTag® assay platform, we developed a dual antibody proximity-based assay for the precise quantitation of HER3 total protein (H3T) from formalin-fixed paraffin-embedded (FFPE) breast tumors. We then measured H3T in 89 patients with metastatic breast cancer treated with trastuzumab-based therapy, and correlated the results with progression-free survival and overall survival using Kaplan–Meier and decision tree analyses that also included HER2 total (H2T) and p95 expression levels. Within the sub-population of patients that over-expressed HER2, high levels of HER3 and/or p95 protein expression were significantly associated with poor clinical outcomes on trastuzumab-based therapy. Based on quantitative H3T, p95, and H2T measurements, multiple subtypes of HER2-positive breast cancer were identified that differ in their outcome following trastuzumab therapy. These data suggest that HER3 and p95 are informative biomarkers of clinical outcomes on trastuzumab therapy, and that multiple subtypes of HER2-positive breast cancer may be defined by quantitative measurements of H3T, p95, and H2T.

The aim of this study was to analyze the correlation between the pathologic complete response (pCR) rate after neoadjuvant chemotherapy and long-term outcome (distant metastases-free survival [DMFS]) in patients with early-stage breast cancer using BluePrint and MammaPrint molecular subtyping versus clinical subtyping using immunohistochemistry/fluorescence in situ hybridization (IHC/FISH) for the determination of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2 (HER2). Data were analyzed from 437 patients in four neoadjuvant chemotherapy trials. BluePrint and MammaPrint outcomes were determined from 44K Agilent arrays, the I-SPY 1 data portal, or Affymetrix U133A arrays. The pCR rate differed substantially among BluePrint molecular subgroups: 6 % in Luminal A-type, 10 % in Luminal B-type, 47 % in HER2-type, and 37 % in Basal-type patients. In the Luminal A-type group (n = 90; including seven HER2-positive patients and eight triple-negative patients by IHC/FISH), the 5-year DMFS rate was 93 %. The pCR rate provided no prognostic information, suggesting these patients may not benefit from chemotherapy. Forty-three of 107 (40 %) HER2-positive patients were classified as Luminal-type by BluePrint and may have lower response rates to targeted therapy. Molecular subtyping identified 90 of 435 (21 %) patients as Luminal A-type (BluePrint Luminal-type/MammaPrint Low Risk) with excellent survival. The pCR rate provided no prognostic information. Molecular subtyping can improve the stratification of patients in the neoadjuvant setting: Luminal A-type (MammaPrint Low Risk) patients have a good prognosis with excellent survival and do not seem to benefit from chemotherapy. We observed marked benefit in response and DMFS to neoadjuvant treatment in patients subtyped as HER2-type and Basal-type. BluePrint with MammaPrint molecular subtyping helps to improve prognostic estimation and the choice of therapy versus IHC/FISH.

The 70-gene prognosis-signature is validated as a good predictor of recurrence for hormone receptor-positive (ER+), lymph node-negative (LN-), human epidermal growth factor receptor type 2-negative (HER2-) early stage breast cancer (ESBC) in Japanese patient population. Its high cost and potential in avoiding unnecessary adjuvant chemotherapy arouse interest in its economic impact. This study evaluates the cost-effectiveness of including the assay into Japan's social health insurance benefit package. An economic decision tree and Markov model under Japan's health system from the societal perspective is constructed with clinical evidence from the pool analysis of validation studies. One-way sensitivity analyses are also performed. Incremental cost-effectiveness ratio is estimated as ¥3,873,922/quality adjusted life year (QALY) (US$43,044/QALY), which is not more than the suggested social willingness-to-pay for one QALY gain from an innovative medical intervention in Japan, ¥5,000,000/QALY (US$55,556/QALY). However, sensitivity analyses show the instability of this estimation. The introduction of the assay into Japanese practice of ER+, LN-, HER2- ESBC treatment by including it to Japan's social health insurance benefit package has a reasonable chance to be judged as cost-effective and may be justified as an efficient deployment of finite health care resources.

HER2 overexpression/amplification is linked with poor prognosis in early breast cancer. Co-expression of HER2 and HER3 is associated with endocrine and chemotherapy resistance, driven not simply by expression but by signalling via HER2:HER3 or HER2:HER2 dimers. Proximity ligation assays (PLAs) detect protein-protein complexes at a single-molecule level and allow study of signalling pathways in situ. A cohort of 100 tumours was analyzed by PLA, IHC and FISH. HER complexes were analyzed by PLA in a further 321 tumours from the BR9601 trial comparing cyclophosphamide, methotrexate and fluorouracil (CMF) with epirubicin followed by CMF (epi-CMF). The relationships between HER dimer expression and RFS and OS were investigated, and multivariate regression analysis identified factors influencing patient prognosis. PLA successfully and reproducibly detected HER2:HER2 and HER2:HER3 protein complexes in vivo. A significant association (P < 0.00001) was identified between HER2 homodimerization and HER2 gene amplification. Following a minimum p value approach high levels of HER2:HER2 dimers were significantly associated with reduced relapse-free (RFS; hazard ratio = 1.72, 95% confidence interval 1.15-2.56, P = 0.008) and overall survival (OS HR = 1.69 95% CI = 1.09-2.62, P = 0.019). Similarly, high levels of HER2:HER3 dimers were associated with reduced RFS (HR = 2.18, 95% CI = 1.46-3.26, P = 0.00016) and OS (HR = 2.21, 95% CI = 1.41-3.47, P = 0.001). This study demonstrates that in situ detection of HER2 and HER2:3 protein:protein complexes can be performed robustly and reproducibly in clinical specimens, provides novel prognostic information and opens a significant novel opportunity to probe the clinical impact of cellular signalling processes.

At recurrence of breast cancer, the therapeutic target is the metastases. However, it is current practice to base the choice of systemic treatment on the biomarker profile of the primary tumor. In the present study, confirmatory biopsies were obtained from suspected metastatic lesions and compared with the primary tumors with respect to ER, HER2, and TOP2A. In the prospective tissue-collection study, 81 patients had biopsy from a suspected relapse. Additional archived paired material was included, leaving a total of 119 patients with paired primary tumor, synchronous axillary nodes (available in 52 patients) and asyncronous metastases available for analysis. ER, HER2, and TOP2A expression of primary tumors, axillary nodes and metastases were re-analysed and determined centrally by immunohistochemistry, chromogenic in situ hybridization, and fluorescence in situ hybridization. Of the 81 patients with a biopsy from a suspected relapse, 65 (80%) were diagnosed with recurrent breast carcinoma, 3 (4%) were diagnosed with other malignancies, 6 (7%) had benign conditions, and in 7 (9%) patients the biopsy was non-representative. Discordance in ER, HER2, and TOP2A (aberration vs. normal) status between primary tumor and corresponding asynchronous metastasis was 12% (14/118), 9% (10/114), and 23% (17/75), respectively. There were no significant associations with biomarker discordance and prior adjuvant therapy, or location of biopsy. Expression of ER, HER2, and TOP2A displayed discordance with a sufficient frequency to emphasize the role of confirmatory biopsies from metastatic lesions in future management of recurrent breast cancer.

Although there are some studies to investigate germline mutations in BRCA1/2 genes in Chinese women with familial breast cancer, many of them suffer relatively small sample size. In this study, we screened germline mutations in BRCA1/2 genes in a cohort of 409 Chinese women with familial breast cancer from north China by using a PCR-sequencing assay. A total of 43 deleterious mutations in BRCA1/2 genes were identified in this cohort, including 17 novel mutations and 6 recurrent mutations. The frequencies of BRCA1 and BRCA2 mutations were 3.9% (16/409) and 6.6% (27/409), respectively; the mutation rate of BRCA2 was 1.7-fold higher than that of BRCA1. The entire mutation rate of BRCA1/2 was 10.5% in this cohort; however, the mutation rate of BRCA1/2 genes was 23.0% in 78 familial breast cancer patients whose tumors were diagnosed at or before the age of 40. The mean age at diagnosis of breast cancer in BRCA1 carriers (42.8 years) and BRCA2 carriers (45.1 years) was younger than non-carriers (51.0 years) in this cohort (P = 0.005; P = 0.01, respectively). In addition, both BRCA1 carriers and BRCA2 carriers were more likely to exhibit triple-negative breast cancer (ER-, PgR-, and HER2-) than non-carriers (BRCA1 carriers vs. non-carriers, 69.2 vs. 23.0%, P = 0.001; BRCA2 carriers vs. non-carriers, 45.8 vs. 23.0%, P = 0.01). Our study suggested that the spectrum and characteristics of BRCA1/2 mutations in Chinese familial breast cancer exhibit some unique features, and Chinese women with familial breast cancer whose tumors are diagnosed at or before the age of 40 are good candidates for BRCA1/2 testing.

The aim of this study is to compare two published nomograms, the "Institut Gustave Roussy/M.D. Anderson Cancer Center" (IGR/MDACC) and the Colleoni nomograms, in predicting pathologic complete responses (pCR) to preoperative chemotherapy in an independent cohort and to assess the impact of HER2 status. Data from 200 patients with breast carcinoma treated with preoperative chemotherapy were collected. We calculated pCR rate predictions with the two nomograms and compared the predictions with the outcomes. Sixty percent of the patients with HER2-positive tumors received trastuzumab concomitantly with taxanes. Model performances were quantified with respect to discrimination and calibration. In the whole population, the area under the ROC curve (AUC) for the IGR/MDACC nomogram and the Colleoni nomogram were 0.74 and 0.75, respectively. Both of them underestimated the pCR rate (P = 0.026 and 0.0005). When patients treated with trastuzumab were excluded, the AUC were excellent: 0.78 for both nomograms with no significant difference between the predicted and the observed pCR (P = 0.14 and 0.15). When the specific population treated with trastuzumab preoperatively was analyzed, the AUC for the IGR/MDACC nomogram and the Colleoni nomogram were poor, 0.52 and 0.53, respectively. The IGR/MDACC and the Colleoni nomograms were accurate in predicting the probability of pCR after preoperative chemotherapy in the HER2-negative population but did not correctly predict pCR in the HER2-positive patients who received trastuzumab. This suggests that responses to preoperative chemotherapy, including trastuzumab, are biologically driven and that a specific nomogram or predictor for HER2-positive patients has to be developed.

An addition of trastuzumab preoperatively to chemotherapy for human epidermal growth factor receptor 2 (HER2) positive breast cancer improved relapse-free survival (RFS). This study was designed to evaluate the efficacy and safety of preoperative paclitaxel, gemcitabine, and trastuzumab (PGH) combination for HER2-positive breast caner. Pathologically, proven node positive stage II/III breast cancer patients with adequate organ function and no history of anti-cancer therapy were eligible. Patients received weekly trastuzumab with paclitaxel 80 mg/m(2) and gemcitabine 1,200 mg/m(2) on days 1 and 8, every 3 weeks for 6 cycles. Postoperatively, patients completed trastuzumab for 1 year and hormone therapy for 5 years if indicated. All patients received postoperative radiation therapy. Of 53 enrolled patients with a median tumor of 5.3 (range, 2.0 to >12) cm; 43.4%, T3/T4; 75.4%, N2/N3; and 45.3%, positive hormone receptors. The pathologic complete response (pCR) rate was 58.5% in both tumor and lymph nodes. Grade 3/4 adverse events were neutropenia (32%), febrile neutropenia (0.6%), and transient elevation of AST/ALT (1.6%) during a total of 318 cycles. All patients maintained normal cardiac function. With a median follow-up of 40 months, 3-year RFS rate was 84% with 91.7% distant metastasis-free survival rates. Remarkable pCR rate was obtained with non-anthracycline-based PGH therapy for HER2-positive stage II/III breast cancer. Adverse events were mild with few incidences of febrile neutropenia.

A cut-off of 5 circulating tumor cells (CTCs) per 7.5 ml of blood in metastatic breast cancer (MBC) patients is highly predictive of outcome. We analyzed the relationship between CTCs as a continuous variable and overall survival in immunohistochemically defined primary tumor molecular subtypes using an artificial neural network (ANN) prognostic tool to determine the shape of the relationship between risk of death and CTC count and to predict individual survival. We analyzed a training dataset of 311 of 517 (60%) consecutive MBC patients who had been treated at MD Anderson Cancer Center from September 2004 to 2009 and who had undergone pre-therapy CTC counts (CellSearch(®)). Age; estrogen, progesterone receptor, and HER2 status; visceral metastasis; metastatic disease sites; therapy type and line; and CTCs as a continuous value were evaluated using ANN. A model with parameter estimates obtained from the training data was tested in a validation set of the remaining 206 (40%) patients. The model estimates were accurate, with good discrimination and calibration. Risk of death, as estimated by ANN, linearly increased with increasing CTC count in all molecular tumor subtypes but was higher in ER+ and triple-negative MBC than in HER2+. The probabilities of survival for the four subtypes with 0 CTC were as follows: ER+/HER2- 0.947, ER+/HER2+ 0.959, ER-/HER2+ 0.902, and ER-/HER2- 0.875. For patients with 200 CTCs, they were ER+/HER2- 0.439, ER+/HER2+ 0.621, ER-/HER2+ 0.307, ER-/HER2- 0.130. In this large study, ANN revealed a linear increase of risk of death in MBC patients with increasing CTC counts in all tumor subtypes. CTCs' prognostic effect was less evident in HER2+ MBC patients treated with targeted therapy. This study may support the concept that the number of CTCs, along with the biologic characteristics, needs to be carefully taken into account in future analysis.

Breast cancer has a long natural history. Established and emerging biologic markers address overall risk but not necessarily timing of recurrence. 346 adjuvant naïve breast cancer cases from Guy's Hospital with 23 years minimum follow-up and archival blocks were recut and reassessed for hormone-receptors (HR), HER2-receptor and grade. Disease-specific survival (DSS) was analyzed by recursive partitioning. To validate insights from this analysis, gene-signatures (proliferative and HR-negative) were evaluated for their ability to predict early versus late metastatic risk in 683 node-negative, adjuvant naïve breast cancers annotated with expression microarray data. Risk partitioning showed that adjuvant naïve node-negative outcome risk was primarily partitioned by tumor receptor status and grade but not tumor size. HR-positive and HER2-negative (HRpos) risk was partitioned by tumor grade; low grade cases have very low early risk but a 20% fall-off in DSS 10 or more years after diagnosis. Higher grade HRpos cases have risk over >20 years. Triple-negative (Tneg) and HER2-positive (HER2pos) cases DSS events occurred primarily within the first 5 years. Among node-positive cases, only low grade conferred late risk, suggesting that proliferative gene signatures that identify proliferation would be important for predicting early but not late recurrence. Using pooled data from four publicly available data sets for node-negative tumors annotated with gene expression and outcome data, we evaluated four prognostic gene signatures: two proliferation-based and two immune function-based. Tumor proliferative capacity predicted early but not late metastatic risk for HRpos cases. The immune function or HRneg specific signatures predicted only early metastatic risk in Tneg and HER2pos cases. Breast cancer prognostic signatures need to inform both risk and timing of metastatic events and may best be applied within subsets. Current signatures predict for outcome risk within 5 years of diagnosis. Predictors of late risk for HR positive disease are needed.

Knowledge is limited about prognostic significance of breast cancer subtypes among women with small invasive node-negative breast tumours. We explored patterns of recurrence in 1691 women with pT1mic/T1a/T1b, pN0 and M0 breast cancer according to four immunohistochemically defined tumour subtypes: (i) Luminal A (ER-positive, PgR-positive, HER2-negative and Ki-67 < 14%); (ii) Luminal B (ER-positive and/or PgR-positive, HER2-positive and/or Ki-67 ≥ 14%); (iii) HER2-positive, both endocrine receptors absent; and (iv) Triple Negative. At multivariate analysis, women with the Triple Negative breast cancer subtype had an increased risk of loco-regional relapse (LRR) (Hazards Ratio (HR) 3.58; 95%CI: 1.40-9.13) and breast cancer related events (HR 2.18; 95%CI: 1.04-4.57). Overall, Luminal B subtype was not associated with a statistically significant increased risk of recurrence compared with Luminal A, while patients with Luminal B subtype tumours overexpressing HER2 had a 2 fold risk of reduced breast cancer related survival (BCS), but not an increased risk of LRR and distant metastases. Women with HER2 breast cancer subtype had a statistically significant increased risk of LRR (HR 4.53; 95%CI: 1.56-13.1), distant metastases and reduced BCS (HR 3.22; 95%CI: 1.44-7.18) and overall survival (HR 2.87; 95%CI: 1.05-7.89) when compared with the Luminal A subtype, at multivariate analysis. In conclusion, women with small size, node-negative, breast cancer are at higher risk of relapse if with HER2-positive endocrine receptor absent or Triple Negative disease.

The authors have investigated the expression of the microcephalin (MCPH1) protein to evaluate its prognostic importance in breast cancer. Microcephalin is a damage response protein involved in the regulation of BRCA1 and BRCA2. BRCA1 mutations are often associated with basal-like breast cancer, which are also often negative for oestrogen receptor (ER), progesterone receptor (PR) and HER2. MCPH1 immunohistochemistry was performed on 319 breast cancers prepared as tissue microarray and correlated with pathology, survival, ER, PR, HER2, EGFR, CK5/6, CK14 and BRCA1 expression. After performing continuous data analysis, mean microcephalin expression decreased with increasing grade (P < 0.006). Mean microcephalin expression was lower in ER/PR negative (P < 0.001) and triple negative cancers (P < 0.004). Conversely, an association with HER2-positive cancers was also identified (P < 0.034). Reduced microcephalin also correlated with reduced nuclear BRCA1 staining (P < 0.001). No association was identified with basal markers. After dichotomising the data into low and high microcephalin expression, reduced expression was identified in 29% (93/319) of breast cancers. An association with low expression was identified in invasive ductal carcinomas with breast cancer-specific survival (BCSS) (P = 0.052). Multivariate analysis of ductal carcinomas showed that microcephalin, together with lymph node involvement and tumour size were independent predictors of BCSS (P = 0.037). Microcephalin expression is reduced in 29% of breast cancers, particularly in higher grade tumours and BRCA1-negative cases. Microcephalin is an independent predictor of BCSS in invasive ductal breast cancer patients and may prove to be a useful biomarker for the identification of aggressive breast cancers.

This retrospective study investigates the correlation of intra-individual HER2 status between primary breast cancers and corresponding recurrences in a population derived cohort. The REMARK criteria were used as reference. In 151 breast cancer patients, primary tumors were analyzed for HER2 status on histopathology sections using immunohistochemistry (IHC) confirmed by fluorescence in situ hybridization (FISH) for IHC 2+ and 3+. Recurrences (loco regional and distant) were investigated by aspiration cytology, using HER2 immunocytochemistry (ICC) or FISH (ICC in 84 patients and FISH in 102 patients). In the 151 patients, sites of recurrence were bone/bone marrow 30%, liver 16%, local recurrence 18%, lung/pleura 10%, axillary lymph nodes 9%, skin (non-local) 7%, supra clavicular lymph nodes 5%, and other sites 7%. In 15 patients (10%) HER2 status changed, 7 of 108 patients (6%) from HER2 negative to HER2 positive and 8 of 43 (19%) from HER2 positive to HER2 negative. Intra-patient agreement in HER2 status was 76% (95% CI 64-87%), and the disagreement was 10% (95% CI 5-15%). The multivariable Cox analysis showed a significantly increased risk of dying in the patient group with changed HER2 status compared to patients with concordant positive HER2 status. Overall survival HR is 5.47 (95% CI 2.01-14.91) and survival from relapse HR is 3.22 (95% CI 1.18-8.77). The unstable status for HER2 in breast cancer is clinically significant and should motivate more frequent testing of recurrences.

The Forkhead Box Protein 3 is highly expressed not only in regulatory T cells, but also in tumor cells, acting as a transcriptional repressor of breast oncogenes including HER2. We investigated the prognostic significance of Foxp3 expression in cancer cells in a large cohort of patients with HER2-overexpressing breast carcinoma treated with neoadjuvant chemotherapy. Foxp3-positive tumor cells were detected by immunohistochemistry in 103 patients with primary invasive HER2-overexpressing breast carcinoma, and treated with neoadjuvant chemotherapy, with or without trastuzumab. Kaplan-Meier analysis and Cox regression model were used to assess relapse-free and overall survival, respectively, and according to the presence or the absence of Foxp3 expression in tumor cells. Breast cancer cells were Foxp3+ in 57% of tumors. Foxp3 expression in breast cancer cells was associated with better relapse-free (P = 0.005) and overall survival (P = 0.03). By multivariate analysis, the presence of Foxp3+ tumor cells produced an independent prognostic factor for both better relapse-free (P = 0.006) and overall survival (P = 0.03). These findings indicate that the presence of Foxp3+ tumor cells represents a new independent prognostic factor of improved outcome in HER2-overexpressing breast carcinoma, which could help identify high-risk patients for additional therapies after neoadjuvant chemotherapy.

HAb18G is a recently identified hepatoma-associated antigen and its association with tumor growth, invasion, and angiogenesis has been studied in a variety of tumors. However, its role in the tumor progression of breast cancer has not been explored. HAb18G expression was examined by immunohistochemistry in pathological sections of 1,637 breast tissue samples and by in situ hybridization in 41 cases of invasive breast carcinomas (BC). While not detected in any cases of tumor-like conditions or benign tumors of breast, and only rarely in normal tissue (4.4%), HAb18G expression was gradually up-regulated from atypical ductal hyperplasia (27.3%), to ductal carcinoma-in situ (59.8%), and to BC (61.4%) (P < 0.01). Its expression in BC was correlated positively with C-erbB-2 expression and histologic grade (P < 0.001), and negatively with the expression of estrogen and progesterone receptors (P < 0.001). Significant differences of expression were also identified among the subgroups of BC examined: in decreasing order from invasive micropapillary carcinoma, ductal carcinoma, lobular carcinoma, papillary carcinoma, medullary carcinoma, to mucinous adenocarcinoma (P = 0.001), corresponding to their known clinical aggressiveness. In an expanded group of 186 BC patients with proper follow up, our previous findings were confirmed: HAb18G expression was significantly associated with local recurrence, distant metastasis and tumor mortality (P < 0.01). We also demonstrated that up-regulated tumor expression of HAb18G was a significant predictor of reduced disease progression-free survival rate and a shorter overall survival, independent of systemic therapies. In conclusion, this study suggests that HAb18G expression is associated with BC progression and prognosis. Further evaluation of this new marker in breast cancer is indicated.

Trastuzumab has conferred significant clinical benefits in HER-2-positive breast carcinomas. HER-2 status is determined by immunohistochemistry (IHC) and/or fluorescence in situ hybridisation (FISH), but appropriate assessment of HER2 status remains subject to considerable debate. Data on the health economic impact of HER-2 test strategies are limited. A life-long Markov state transition model was used to assess costs and effectiveness of HER-2 assay strategies (based on IHC, FISH, both combined or FISH confirmation of IHC2+) for a hypothetical cohort of early breast cancer patients from the perspective of the Swiss health system. We compared clinically relevant strategies of predictive testing and subsequent trastuzumab treatment of HER-2-positive patients only. FISH testing was the most cost-effective strategy with an incremental cost-effectiveness ratio of €12,245 per additional quality-adjusted life-year (QALY) gained, compared to no trastuzumab treatment. The next best strategy was parallel IHC and FISH, with costs of €400,154/QALY gained compared to FISH alone. FISH as primary HER-2 testing modality remained the preferred option in deterministic and probabilistic sensitivity analysis. Predictive testing to identify adjuvant breast cancer patients who benefit from trastuzumab treatment is a clinical and economic necessity. Our model identifies FISH as the most cost-effective approach.

We investigated the association between the risk of locoregional recurrence (LRR) and biological subtypes defined by hormonal receptors (HR) and HER-2 status in women with invasive breast cancer (BC). A total of 618 newly diagnosed BC patients were identified from a cancer registry within a single institution with standardized methods of tumor assessment for estrogen receptor (ER), progesterone receptor (PR), and HER-2. Patients were stratified based on surgical treatment, breast-conserving therapy (BCT) versus modified radical mastectomy (MRM), as well as biological subtypes: HR+/HER-2- (ER-positive or PR-positive, HER-2-negative), HR+/HER-2+ (ER-positive or PR-positive, HER-2-positive), HR-/HER-2+ (ER-negative and PR-negative, HER-2-positive) and TN (ER-negative, PR-negative and HER-2-negative). The association between clinicopathological factors, biological subtype and LRR was evaluated with univariate and multivariate Cox analysis. With a median follow-up of 4.8 years, the rate of LRR was 7.5%. On multivariate analysis, TN, tumor size ≥2 cm and lymph node (LN) positivity were associated with increased risk of LRR (P = 0.023, P = 0.048, and P = 0.0034, respectively). In BCT group, HR-/HER-2+ and LN positivity were associated with increased risk of LRR (HR 11.13; 95% CI 2.78-44.53; P = 0.0007 and HR 5.40; 95% CI 1.67-17.43; P = 0.0048, respectively). In MRM group, TN subtype and LN positivity were associated with increased risk of LRR (HR 4.72; 95% CI 1.53-14.52; P = 0.0069 and HR 3.23; 95% CI 1.44-7.29; P = 0.0047, respectively). Compared to HR+/HER-2-, HR-/HER-2+ treated by BCT and TN treated by MRM showed a significant decrease of 5-year LRR free survival (P = 0.0002 and P = 0.002, respectively). Tumor profiling using ER, PR, and HER-2 biomarkers is a promising tool to identify patients at high risk of LRR based on surgical treatment. Our findings suggest a different follow-up and locoregional treatment for patients with HR-/HER-2+ and TN subtypes.

This study was designed to quantify and identify differences in protein levels between tumor and adjacent normal breast tissue from the same breast in 18 women with stage I/II ER positive/Her2/neu negative invasive breast cancer. Eighteen separate difference gel electrophoresis (DIGE) gels were run (1 gel per patient). Relative quantification was based on DIGE analysis. After excision and tryptic digestion, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and peptide mass mapping were used to identify protein spots. Two hundred and forty-three spots were differentially abundant between normal and cancer tissues. Fifty spots were identified: 41 were over abundant and nine were less abundant in cancers than in normal breast tissue. Western blotting provided independent confirmation for three of the most biologically and statistically interesting proteins. All 18 gels were replicated by another technician and 32% of the differentially abundant proteins were verified by the duplicate analysis. Follow-up studies are now examining these proteins as biomarkers in blood.

Absence of hormonal receptors (HR) expression is a predictive factor of high pathologic complete response (pCR) rate after neo-adjuvant chemotherapy. However, HR-positive tumors are less chemosensitive. In the present study, we evaluated the predictive value of estrogen (ER) and progesterone (PgR) semi-quantitative expression in patients with HR-positive tumors treated uniformly with antracycline-based neoadjuvant chemotherapy without hormonal treatment. Value of HR expression as a predictive factor was then evaluated in a multivariate analysis with tumor grade, Ki67 index and HER2 expression. From January 2000 and December 2006, 177 patients with HR-positive breast ductal invasive carcinoma ≥2 cm in its largest diameter were treated with six cycles of an anthracycline-based neo-adjuvant chemotherapy. Tumor grade, ER, PgR, HER2 status and Ki67 index were determined on microbiopsy performed before chemotherapy. A semi-quantitative evaluation of ER and PgR expression by IHC was performed using the Barnes'score. pCR rate was significantly different (P < 0.001) according to the ER expression score. pCR rate was 28% for low score, 9% for medium score and 3% for high score. On the contrary, pCR rate was not significantly different (P = 0.49) according to the PgR expression score. In the multivariate analysis, ER expression score (P = 0.0002) and Ki67 index (P = 0.02) were the only predictive factors of response for HR-positive tumors. pCR after anthracycline-based chemotherapy is significantly correlated with the ER expression score.

In order to explore the effect of neoadjuvant chemotherapy (NACT) on clinical mid-course and pathological complete response (pCR) at surgery in different biological breast cancer subtypes. The GeparTrio study included 2,072 patients with operable or locally advanced breast cancer. After two cycles with docetaxel, doxorubicin and cyclophosphamide (TAC) patients were randomized according to their clinical response. Clinical and biological factors were assessed for predicting clinically mid-course response and pCR at surgery. The overall pCR rate, defined as no invasive residuals in breast and axilla, was 20.5%. The highest pCR rate of 57% was observed in patients below 40 years of age with triple negative or grade 3 tumors. Independent factors for mid-course response and pCR were: young age, non-T4 tumors, high grade, and hormone receptor status, the strongest single predictive factor. Within the biological subtypes, grading was an independent factor to predict pCR for luminal tumors, clinical tumor stage for the HER2 like tumors and age for the triple negative ones. Grading gave independent information for mid-course response within the triple negative group. No factor predicted mid-course response within the other groups. Grading and age can identify subgroups within the luminal and triple negative patients who have an increased benefit from NACT.

In order to examine the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-P) in combination with bevacizumab (B) and gemcitabine (G) for the first-line treatment of patients with HER2-negative metastatic breast cancer (MBC). In this single-center, open-label phase II trial, patients with HER2-negative MBC received gemcitabine 1500 mg/m(2), nab-paclitaxel 150 mg/m(2), and bevacizumab 10 mg/kg (each administered intravenously) on days 1 and 15 of a 28-day cycle. The primary end point was progression free survival (PFS); secondary end points were overall response rate (ORR), complete (CR) and partial (PR) response rates, clinical benefit (ORR + stable disease), overall survival (OS), and safety. Thirty patients were enrolled. One patient was ineligible and was not included in analysis. Median PFS was 10.4 months (95% CI: 5.6-15.2 months). ORR was 75.9%, comprising eight (27.6%) CRs and 14 (48.3%) PRs; five patients had stable disease (SD) and two patients (6.9%) had progressive disease (PD) as their best response. The clinical benefit rate was 93.1% (27/29) in the overall group and 84.6% in the triple-negative cohort (11/13). The 18-month survival rate was 77.2% (95% CI: 51.1-90.5%). Eight (27.6%) patients experienced grade 3 or 4 toxicity: grade 4 neutropenic fever (n = 1) and grade 3 infection (n = 6), leukopenia, thrombocytopenia, peripheral neuropathy, seizure, shortness of breath, hematuria, and cardiac tamponade (one each). First-line therapy with nab-P, B, and G demonstrated a median PFS of 10.4 months and a 75.9% ORR with acceptable toxicity; this novel combination warrants investigation in a randomized study.

The aim of this study is to test the hypothesis that antiangiogenic treatment with sunitinib consolidation can prolong remissions induced by taxane-based chemotherapy in women with metastatic breast cancer. The method involves a two-arm open-label (2:1 randomization) multicenter, randomized phase II trial evaluating the efficacy of sunitinib (arm A) versus no therapy (arm B) in patients with HER-2-negative metastatic breast cancer who achieved an objective response to taxane-based chemotherapy. The results of this study indicates that the primary endpoint of progression-free survival (PFS) > or =5 months was achieved in 10 of 36 patients (28%) in arm A and 4 of 19 patients (21%) in arm B. The median PFS was 2.8 and 3.1 months, respectively. A protocol amendment to the sunitinib dosing schedule was made because 53% (17/32) of patients treated at a starting dose of 50 mg (4 weeks on/2 weeks off) required dose reduction. Changing the starting dose to sunitinib 37.5 mg continuously resulted in dose reductions in 44% (7/16) of patients. Grades III-IV toxicity occurred in 69% of patients in arm A (fatigue 31%, musculoskeletal pain 11%, neutropenia and thrombopenia 8%) and 11% in arm B. The proof-of-principle study does not confirm the hypothesis that sunitinib consolidation therapy can lead to a predefined clinically relevant proportion of patients with PFS of > or =5 months after an objective response to taxanes. Furthermore, toxicity was significant.

nab-Paclitaxel has shown favorable efficacy and toxicity profiles compared to other taxanes in the treatment of metastatic breast cancer. In this pilot trial, we evaluated a nab-paclitaxel-containing adjuvant regimen in patients with early stage breast cancer. Patients with node-positive or high-risk node-negative early-stage breast cancer were eligible following completion of standard primary therapy. All the patients received four cycles, at 21-day intervals, of nab-paclitaxel (100 mg/m(2) IV days 1, 8, and 15) and cyclophosphamide (600 mg/m(2) IV day 1). HER2-positive patients also received trastuzumab 8 mg/kg IV on cycle 1 day 1, followed by 6 mg/kg every 21 days for a total of 52 weeks. The purpose of this trial was to evaluate feasibility and toxicity of this nab-paclitaxel-containing adjuvant regimen. 62 patients were treated between 2/08 and 11/08. The majority of the patients (87%) were HER2-negative. This adjuvant regimen was well tolerated, and full doses of all agents were administered in >90% of cycles. Grade 3/4 neutropenia occurred in 53% of the patients; however, only one episode of febrile neutropenia occurred in a total of 249 cycles administered. Other grade 3/4 adverse events occurred in less than 5% of patients. After short follow-up, all the patients remain alive and disease-free. The combination of nab-paclitaxel and cyclophosphamide, with or without trastuzumab, is feasible and well tolerated in patients with early stage breast cancer. Further investigation of the role of nab-paclitaxel in adjuvant breast cancer therapy is indicated, but definitive evaluation will require randomized phase III trials.

The implications of Phosphatidylinositol 3-kinase (PIK3CA) mutations and its aberrant protein expression in breast cancer (BC) different molecular subtypes and patients' outcome remain controversial. The aims of this study were to assess the prevalence and clinical significance of PIK3CA protein expression in BC and to determine its association with its different molecular classes. PIK3CA protein expression was assessed in a well-characterized series of early stage BC (n = 1,394) with long-term follow-up, using tissue microarrays and immunohistochemistry. Associations between PIK3CA expression and clinicopathological variables, molecular classes, and patients' outcome were investigated. Positive PIK3CA expression was associated with poor prognostic variables including higher grade, larger size, nodal involvement, vascular invasion, and higher proliferative fraction (P < 0.001). Increased PIK3CA expression was associated with the basal-like breast cancer (BLBC) and HER2-positive classes as well as triple negative non-basal (TNnon-B) tumors (P < 0.001). The luminal class showed reduced PIK3CA expression relative to other classes. Patients with PIK3CA positive tumors had shorter BC specific and disease free survival, independent of other prognostic factors except grade. Similar associations with outcome were found when the analysis was restricted to the large luminal class of tumors. PIK3CA is an oncogenic biomarker associated with poor prognosis in BC. Although, PIK3CA over-expression was more prevalent in BLBC and HER2-positive tumors it appeared to be a marker of poor differentiation rather than of a particular subtype. Thus, targeting of PIK3CA using specific inhibitors could potentially be beneficial, particularly for patients with more aggressive poorly differentiated tumors, irrespective of their molecular subtype.

Breast cancers can be classified into those that express the estrogen (ER) and progesterone (PR) receptors, those with ERBB2 (HER-2/Neu) amplification, and those without expression of ER, PR, or amplification of ERBB2 (referred to as triple-negative or basal-like breast cancer). In order to identify potential molecular targets in breast cancer, we performed a synthetic siRNA-mediated RNAi screen of the human tyrosine kinome. A primary RNAi screen conducted in the triple-negative/basal-like breast cancer cell line MDA-MB231 followed by secondary RNAi screens and further studies in this cell line and two additional triple-negative/basal-like breast cancer cell lines, BT20 and HCC1937, identified the G2/M checkpoint protein, WEE1, as a potential therapeutic target. Similar sensitivity to WEE1 inhibition was observed in cell lines from all subtypes of breast cancer. RNAi-mediated silencing or small compound inhibition of WEE1 in breast cancer cell lines resulted in an increase in gammaH2AX levels, arrest in the S-phase of the cell cycle, and a significant decrease in cell proliferation. WEE1-inhibited cells underwent apoptosis as demonstrated by positive Annexin V staining, increased sub-G1 DNA content, apoptotic morphology, caspase activation, and rescue by the pan-caspase inhibitor, Z-VAD-FMK. In contrast, the non-transformed mammary epithelial cell line, MCF10A, did not exhibit any of these downstream effects following WEE1 silencing or inhibition. These results identify WEE1 as a potential molecular target in breast cancer.

Decreased expression of Numb, resulting in activation of the proto-oncogene Notch1 and reduction in the tumor suppressor p53, has been demonstrated in mammary carcinomas. The aim of this study was to investigate the relationship between Numb protein expression and clinicopathological characteristics, tumor biological subtypes and putative cancer stem cell markers in a well-characterized cohort of primary human breast cancers. Immunohistochemistry was performed on tissue microarrays of primary invasive breast tumors using a polyclonal anti-Numb primary antibody. Of the 241 tumors evaluated, 50 (21%) displayed deficient or reduced Numb immunoreactivity. Retained Numb expression was significantly correlated to estrogen (ER) and progesterone receptor (PR) positivity (P < 0.001 and P = 0.004, respectively). Interestingly, we found that a higher percentage of the tumors with deficient or reduced Numb expression belonged to the triple-negative (ER-/PR-/HER2-) subgroup compared to tumors with retained Numb expression (P = 0.004). Transcriptional profiling of a subset of these tumors linked NOTCH1 and BIRC5, both downstream targets of Numb, to the triple-negative subgroup in an inverse manner. Typically, subgroups characterized by the low expression of Numb expressed higher levels of NOTCH1 and BIRC5 (encoding survivin). We also found deficient expression of Numb in a significantly higher proportion of BRCA1 dependent tumors, which are usually triple-negative, compared to sporadic tumors. The expression of Numb in 14 breast cancer cell lines correlated similarly to their respective molecular subtypes. We further established an inverse correlation between the Numb expression levels and the CD44+/CD24- cancer stem cell phenotype (P = 0.05) in primary tumors. Finally, decreased Numb expression was associated with poorer distant disease-free survival (P = 0.01). Taken together, our results indicate that loss of Numb expression is a marker of tumor aggressiveness, potentially linked to BRCA1 status and a cancer stem cell phenotype in primary breast cancer.

Pooling of microarray datasets seems to be a reasonable approach to increase sample size when a heterogeneous disease like breast cancer is concerned. Different methods for the adaption of datasets have been used in the literature. We have analyzed influences of these strategies using a pool of 3,030 Affymetrix U133A microarrays from breast cancer samples. We present data on the resulting concordance with biochemical assays of well known parameters and highlight critical pitfalls. We further propose a method for the inference of cutoff values directly from the data without prior knowledge of the true result. The cutoffs derived by this method displayed high specificity and sensitivity. Markers with a bimodal distribution like ER, PgR, and HER2 discriminate different biological subtypes of disease with distinct clinical courses. In contrast, markers displaying a continuous distribution like proliferation markers as Ki67 rather describe the composition of the mixture of cells in the tumor.

The present study was designed to assess the clinical characteristics and outcomes of metaplastic breast cancer (MBC) compared to general invasive ductal carcinoma (IDC) and the triple-negative subtype (TN-IDC). The study population included 35 MBC and 2,839 IDC patients, including 473 TN-IDC diagnoses, from the National Cancer Center, Korea between 2001 and 2008. The clinicopathological characteristics and clinical outcomes were retrospectively reviewed. Mean age of patients was 47.4 years for the MBC group and 48.3 years for the IDC group. The MBC patients presented with a larger tumor size (>/=T2, 74.3% vs. 38.8%, P < 0.001), more distant metastasis at the first diagnosis (8.6% vs. 2.0%, P = 0.04), higher histologic grade (grade 3, 65.7% vs. 41.4%, P < 0.001), fewer estrogen receptor (ER), and progesterone receptor (PgR) positivity (ER+, 5.7% vs. 65.4%, P < 0.001; PgR+, 8.6% vs. 55.8%, P < 0.001), higher Ki-67 expression (35.5 +/- 26.2% vs. 20.6 +/- 19.8%, P = 0.024), and more TN subtypes (80.0% vs. 16.7%, P < 0.001) compared to the IDC group. Fifteen (46.8%) MBC patients and 260 (9.3%) IDC patients experienced disease recurrence with a median follow-up of 47.2 months (range 4.9-100.6 months). MBC was a poor prognostic factor for disease recurrence and overall survival in univariate and multivariate analysis (HR 3.89 in recurrence, 95% CI: 1.36-11.14, P = 0.01; HR 5.29 in death, 95% CI: 2.15-13.01, P < 0.001). MBC patients also experienced more disease recurrence (HR 3.99, 95% CI: 1.31-12.19, P = 0.01) and poorer overall survival (HR 3.14, 95% CI: 1.19-8.29, P = 0.02) compared to the 473 TN-IDC patients, as reflected by aggressive pathological features. Patients with MBC appeared to have inherently aggressive tumor biology with poorer clinical outcomes than those with general IDC or TN-IDC.

Obtaining negative margins is critical for breast cancer patients undergoing conservation therapy in order to reduce the reemergence of the original cancer. Currently, breast cancer tumor margins are examined in a pathology lab either while the patient is anesthetized or after the surgical procedure has been terminated. These current methods often result in cancer cells present at the surgical resection margin due to inadequate margin assessment at the point of care. Due to such limitations evident in current diagnoses, tools for increasing the accuracy and speed of tumor margin detection directly in the operating room are still needed. We are exploring the potential of using a nano-biophotonics system to facilitate intraoperative tumor margin assessment ex vivo at the cellular level. By combining bioconjugated silica-based gold nanoshells, which scatter light in the near-infrared, with a portable FDA-approved reflectance confocal microscope, we first validate the use of gold nanoshells as effective reflectance-based imaging probes by evaluating the contrast enhancement of three different HER2-overexpressing cell lines. Additionally, we demonstrate the ability to detect HER2-overexpressing cells in human tissue sections within 5 min of incubation time. This work supports the use of targeted silica-based gold nanoshells as potential real-time molecular probes for HER2-overexpression in human tissue.

Historical data have indicated the potential for the histologically-normal breast to harbor pre-malignant changes at the molecular level. We postulated that a histologically-normal tissue with "tumor-like" gene expression pattern might harbor substantial risk for future cancer development. Genes associated with these high-risk tissues were considered to be "malignancy-risk genes". From a total of 90 breast cancer patients, we collected a set of 143 histologically-normal breast tissues derived from patients harboring breast cancer who underwent curative mastectomy, as well as a set of 42 invasive ductal carcinomas (IDC) of various histologic grades. All samples were assessed for global gene expression differences using microarray analysis. For the purpose of this study we defined normal breast tissue to include histologically normal and benign lesions. Here we report the discovery of a "malignancy-risk" gene signature that may portend risk of breast cancer development in benign, but molecularly-abnormal, breast tissue. Pathway analysis showed that the malignancy-risk signature had a dramatic enrichment for genes with proliferative function, but appears to be independent of ER, PR, and HER2 status. The signature was validated by RT-PCR, with a high correlation (Pearson correlation = 0.95 with P < 0.0001) with microarray data. These results suggest a predictive role for the malignancy-risk signature in normal breast tissue. Proliferative biology dominates the earliest stages of tumor development.

Oestrogen receptor (ER) negative breast cancers are more likely to achieve a pathological complete response (pCR) to neoadjuvant chemotherapy compared to those with ER positive tumours. ER positive tumours exhibit low proliferation and ER negative cancers high proliferation. The aim of this study was to determine to what extent the better response of ER negative cancers correlates with proliferation rate. A retrospective analysis of a prospectively maintained database identified 175 neoadjuvant chemotherapy patients with tissue available for Ki67 analysis. On univariate analysis, pre-therapy Ki67 (P = 0.04), ER status (P = 0.002), HER2 status (P = 0.004) and grade (P = 0.0009) were associated with a pCR. In a multivariate model, HER2 was the only significant predictor of pCR. No significant relationship between pre-therapy Ki67 and relapse-free and overall survival was demonstrated. Ki67 is not an independent predictor of clinical CR or pCR. Aspects of ER status beyond its inverse relationship with proliferation may contribute to its predictive value for pCR.

The CAN-NCIC-MA22 phase I/II clinical trial evaluated women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel at 2 or 3 weekly intervals in sequential cohorts. The relationship between various biomarkers and treatment response was assessed. Breast biopsy cores were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of estrogen receptor (ER), progesterone receptor (PR), Her2/Neu protein (HER2), and topoisomerase II (Topo 2),expressed as percent positive stain. Tumor RNA integrity(RIN) and tumor cellularity were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after hematoxylin/eosin staining, respectively.Associations between 1) maximum RIN and 2) tumor cellularity at the three time points with baseline levels of ER,PR, Her2, and topo II were assessed using Spearman and Pearson correlation coefficients. Associations between RIN and tumor cellularity with chemotherapy dose level orpathologic response were assessed using one-way ANOVA.In this study, we observed that low mid-treatment maximum RIN (but not tumor cellularity) was associated with high chemotherapy drug dose level (P = 0.05) and eventual pathologic complete response (pCR) (P = 0.01). Posttreatment,low maximum RIN was found to be associated with low tumor cellularity (P = 0.004), and low tumor cellularity with pCR (P = 0.01). Post-treatment tumor cellularity was lowest in patients with tumors having high baseline PR levels (P = 0.05). The association of midtreatment RIN with drug dose level and with pCR suggests that tumor RIN may represent an important new biomarker for measuring response to chemotherapy in breast cancer patients.

Mutations in the alpha catalytic subunit of phosphoinositol-3-kinase (PIK3CA) occur in approximately 30% of ER positive breast cancers. We therefore sought to determine the impact of PIK3CA mutation on response to neoadjuvant endocrine therapy. Exons 9 (helical domain) and 20 (kinase domain-KD) mutations in PIK3CA were determined samples from four neoadjuvant endocrine therapy trials.Interactions with clinical, pathological, and biomarker response parameters were examined. A weak negative interaction between PIK3CA mutation status and clinical response to neoadjuvant endocrine treatment was detected(N = 235 P < or = 0.05), but not with treatment-induced changes in Ki67-based proliferation index (N = 418). Despite these findings, PIK3CA KD mutation was a favorable prognostic factor for relapse-free survival (RFS log-rank P = 0.02) in the P024 trial (N = 153). The favorable prognostic effect was maintained in a multivariable analysis(N = 125) that included the preoperative endocrine prognostic index, an approach to predicting RFS based on post neoadjuvant endocrine therapy pathological stage, ER, and Ki67 levels (HR for no PIK3CA KD mutation, 14, CI 1.9-105 P = 0.01). PIK3CA mutation status did not strongly interact with neoadjuvant endocrine therapy responsiveness in estrogen receptor-positive breast cancer. Nonetheless, as with other recent studies, a favorable interaction between PIK3CA KD mutation and prognosis was detected. The mechanism for the favorable prognostic impact of PIK3CA mutation status therefore remains unexplained.