Clinicopathological and surgical factors associated with long-term survival in patients with HER2-positive metastatic breast cancer.

Trastuzumab-based treatment has dramatically improved the outcomes of HER2-positive (HER2+) metastatic breast cancer (MBC) patients, with some patients achieving prolonged survival times. In this study, we aim to identify factors that are associated with long-term survival. Patients with HER2+ MBC treated with anti-HER2 target therapy were identified. Patients were grouped according to overall survival (OS) and categorized as long-term survivors (LTS, OS ≥ 5 years), or non-long-term survivors (non-LTS, OS < 5 years). Descriptive statistics and multivariable logistic regression modeling were used. A sensitivity analysis was carried out, including only patients diagnosed before 2007; therefore, 5 years of potential follow-up was possible. 1063 patients with HER2+ MBC diagnosed between 1994 and 2012 and treated with anti-HER2 therapy were identified. Among them, 154 (14.5 %) patients were categorized as LTS (median OS 92.2 months). Among LTS, 63.4 % were HR-positive and 32 % had de novo stage IV disease. Hormone receptor positivity (OR) 1.69; 95 % CI 1.17-2.44), resection of metastases (OR 2.38; 95 % CI 1.53-3.69), and primary breast surgery in patients with de novo stage IV (OR 2.88; 95 % CI 1.47-5.66) were associated with improved long-term survival. Greater number of metastatic sites (≥3 vs. 1, OR 0.41; 95 % CI 0.23-0.72) and visceral metastases (OR 0.61; 95 % CI 0.4-0.91) were associated with poor survival. Hormone receptor positivity, low burden of disease, metastasis to soft and bone tissues, and surgical management with resection of the metastatic site and the primary tumor were associated with long-term survival in patients with MBC who received anti-HER2 treatment.

A Set of miRNAs, Their Gene and Protein Targets and Stromal Genes Distinguish Early from Late Onset ER Positive Breast Cancer.

UNLABELLED: Breast cancer (BC) in young adult patients (YA) has a more aggressive biological behavior and is associated with a worse prognosis than BC arising in middle aged patients (MA). We proposed that differentially expressed miRNAs could regulate genes and proteins underlying aggressive phenotypes of breast tumors in YA patients when compared to those arising in MA patients. OBJECTIVE: Using integrated expression analyses of miRs, their mRNA and protein targets and stromal gene expression, we aimed to identify differentially expressed profiles between tumors from YA-BC and MA-BC. METHODOLOGY AND RESULTS: Samples of ER+ invasive ductal breast carcinomas, divided into two groups: YA-BC (35 years or less) or MA-BC (50-65 years) were evaluated. Screening for BRCA1/2 status according to the BOADICEA program indicated low risk of patients being carriers of these mutations. Aggressive characteristics were more evident in YA-BC versus MA-BC. Performing qPCR, we identified eight miRs differentially expressed (miR-9, 18b, 33b, 106a, 106b, 210, 518a-3p and miR-372) between YA-BC and MA-BC tumors with high confidence statement, which were associated with aggressive clinicopathological characteristics. The expression profiles by microarray identified 602 predicted target genes associated to proliferation, cell cycle and development biological functions. Performing RPPA, 24 target proteins differed between both groups and 21 were interconnected within a network protein-protein interactions associated with proliferation, development and metabolism pathways over represented in YA-BC. Combination of eight mRNA targets or the combination of eight target proteins defined indicators able to classify individual samples into YA-BC or MA-BC groups. Fibroblast-enriched stroma expression profile analysis resulted in 308 stromal genes differentially expressed between YA-BC and MA-BC. CONCLUSION: We defined a set of differentially expressed miRNAs, their mRNAs and protein targets and stromal genes that distinguish early onset from late onset ER positive breast cancers which may be involved with tumor aggressiveness of YA-BC.

A preoperative nomogram to predict the risk of synchronous distant metastases at diagnosis of primary breast cancer.

BACKGROUND: The detection of synchronous metastases at primary diagnosis of breast cancer (BC) affects its initial management. A risk calculator that incorporates many factors to evaluate an individual's risk of harbouring synchronous metastases would be useful to adapt cancer management. PATIENTS AND METHODS: Patients with primary diagnosis of BC were identified from three institutional databases sharing homogeneous work-up recommendations. A risk score for synchronous metastases was estimated and a nomogram was constructed using the first database. Its performance was assessed by receiver characteristic (ROC) analysis. The nomogram was externally validated in the two independent cohorts. RESULTS: A preoperative nomogram based on the clinical tumour size (P<0.001), clinical nodal status (P<0.001), oestrogen (P=0.17) and progesterone receptors (P=0.04) was developed. The nomogram accuracy was 87.3% (95% confidence interval (CI), 84.45-90.2%). Overall, the area under the ROC curve (AUC) was 86.1% for the validation set from the Institut Curie-René Huguenin, and 63.8% for the MD Anderson validation set. The negative predictive value (NPV) was high in the three cohorts (97-99%). CONCLUSIONS: We developed and validated a strong metastasis risk calculator that can evaluate with high accuracy an individual's risk of harbouring synchronous metastases at diagnosis of primary BC. CONDENSED ABSTRACT: A nomogram to predict synchronous metastases at diagnosis of breast cancer was developed and externally validated. This tool allows avoiding unnecessary expensive work-up.

Effect of adjuvant trastuzumab among patients treated with anti-HER2-based neoadjuvant therapy.

PURPOSE: To study the impact of adjuvant trastuzumab among patients achieving a pathologic complete response (pCR) after trastuzumab-based neoadjuvant systemic therapy (NST). PATIENTS AND METHODS: Patients with primary HER2-positive breast cancer treated with trastuzumab-based NST were categorised according to adjuvant trastuzumab administration and pCR status. Adjuvant trastuzumab became standard of care in 2006, this was the main reason patients in our cohort did not receive adjuvant trastuzumab. Kaplan-Meier was used to estimate survival. A test for interaction between adjuvant trastuzumab and pCR was completed. FINDINGS: Of 589 patients, 203 (34.5%) achieved a pCR. After surgery, 109 (18.5%) patients in the entire cohort did not receive adjuvant trastuzumab. Among patients achieving a pCR, 31.3% received adjuvant trastuzumab compared with 68.8% among those who did not achieve a pCR (P=0.0006). Among patients achieving pCR, adjuvant trastuzumab did not further improve overall survival (OS) or relapse-free survival (RFS) (P=0.35 and P=0.93, respectively). Any benefit of adjuvant trastuzumab in OS and RFS among patients without a pCR did not achieve statistical significance (P=0.3 and P=0.44, respectively). CONCLUSIONS: In this cohort, patients treated with trastuzumab-based NST who achieved a pCR have excellent outcome regardless of whether they received adjuvant trastuzumab.

P-REX1 creates a positive feedback loop to activate growth factor receptor, PI3K/AKT and MEK/ERK signaling in breast cancer.

Phosphatidylinositol 3-kinase (PI3K) promotes cancer cell survival, migration, growth and proliferation by generating phosphatidylinositol 3,4,5-trisphosphate (PIP3) in the inner leaflet of the plasma membrane. PIP3 recruits pleckstrin homology domain-containing proteins to the membrane to activate oncogenic signaling cascades. Anticancer therapeutics targeting the PI3K/AKT/mTOR (mammalian target of rapamycin) pathway are in clinical development. In a mass spectrometric screen to identify PIP3-regulated proteins in breast cancer cells, levels of the Rac activator PIP3-dependent Rac exchange factor-1 (P-REX1) increased in response to PI3K inhibition, and decreased upon loss of the PI3K antagonist phosphatase and tensin homolog (PTEN). P-REX1 mRNA and protein levels were positively correlated with ER expression, and inversely correlated with PI3K pathway activation in breast tumors as assessed by gene expression and phosphoproteomic analyses. P-REX1 increased activation of Rac1, PI3K/AKT and MEK/ERK signaling in a PTEN-independent manner, and promoted cell and tumor viability. Loss of P-REX1 or inhibition of Rac suppressed PI3K/AKT and MEK/ERK, and decreased viability. P-REX1 also promoted insulin-like growth factor-1 receptor activation, suggesting that P-REX1 provides positive feedback to activators upstream of PI3K. In support of a model where PIP3-driven P-REX1 promotes both PI3K/AKT and MEK/ERK signaling, high levels of P-REX1 mRNA (but not phospho-AKT or a transcriptomic signature of PI3K activation) were predictive of sensitivity to PI3K inhibitors among breast cancer cell lines. P-REX1 expression was highest in estrogen receptor-positive breast tumors compared with many other cancer subtypes, suggesting that neutralizing the P-REX1/Rac axis may provide a novel therapeutic approach to selectively abrogate oncogenic signaling in breast cancer cells.

Survival of women with inflammatory breast cancer: a large population-based study.

BACKGROUND: Our group has previously reported that women with inflammatory breast cancer (IBC) continue to have worse outcome compared with those with non-IBC. We undertook this population-based study to see if there have been improvements in survival among women with stage III IBC, over time. PATIENT AND METHODS: We searched the Surveillance, Epidemiology and End Results Registry to identify female patients diagnosed with stage III IBC between 1990 and 2010. Patients were divided into four groups according to year of diagnosis: 1990-1995, 1996-2000, 2001-2005, and 2006-2010. Breast cancer-specific survival (BCSS) was estimated using the Kaplan-Meier method and compared across groups using the log-rank test. Cox models were then fit to determine the association of year of diagnosis and BCSS after adjusting for patient and tumor characteristics. RESULTS: A total of 7679 patients with IBC were identified of whom 1084 patients (14.1%) were diagnosed between 1990 and 1995, 1614 patients (21.0%) between 1996 and 2000, 2683 patients (34.9%) between 2001 and 2005, and 2298 patients (29.9%) between 2006 and 2010. The 2-year BCSS for the whole cohort was 71%. Two-year BCSS were 62%, 67%, 72%, and 76% for patients diagnosed between 1990-1995, 1996-2000, 2001-2005, and 2006-2010, respectively (P < 0.0001). In the multivariable analysis, increasing year of diagnosis (modeled as a continuous variable) was associated with decreasing risks of death from breast cancer (HR = 0.98, 95% confidence interval 0.97-0.99, P < 0.0001). CONCLUSION: There has been a significant improvement in survival of patients diagnosed with IBC over a two-decade time span in this large population-based study. This suggests that therapeutic strategies researched and evolved in the context of non-IBC have also had a positive impact in women with IBC.

Open-label randomized clinical trial of standard neoadjuvant chemotherapy with paclitaxel followed by FEC versus the combination of paclitaxel and everolimus followed by FEC in women with triple receptor-negative breast cancer†.

BACKGROUND: Everolimus synergistically enhances taxane-induced cytotoxicity in breast cancer cells in vitro and in vivo in addition to demonstrating a direct antiproliferative activity. We aim to determine pharmacodynamics changes and response of adding everolimus to standard neoadjuvant chemotherapy in triple-negative breast cancer (TNBC). PATIENTS AND METHODS: Phase II study in patients with primary TNBC randomized to T-FEC (paclitaxel 80 mg/m(2) i.v. weekly for 12 weeks, followed by 5-fluorouracil 500 mg/m(2), epirubicin 100 mg/m(2), and cyclophosphamide 500 mg/m(2) every 3 weeks for four cycles) versus TR-FEC (paclitaxel 80 mg/m(2) i.v. and everolimus 30 mg PO weekly for 12 weeks, followed by FEC). Tumor samples were collected to assess molecular changes in the PI3K/AKT/mTOR pathway, at baseline, 48 h, 12 weeks, and at surgery by reverse phase protein arrays (RPPA). Clinical end points included 12-week clinical response rate (12-week RR), pathological complete response (pCR), and toxicity. RESULTS: Sixty-two patients were registered, and 50 were randomized, 27 received T-FEC, and 23 received TR-FEC. Median age was 48 (range 31-75). There was downregulation of the mTOR pathway at 48 h in the TR-FEC arm. Twelve-week RR by ultrasound were 29.6% versus 47.8%, (P = 0.075), and pCR were 25.9% versus 30.4% (P = 0.76) for T-FEC and TR-FEC, respectively. mTOR downregulation at 48 h did not correlate with 12-week RR in the TR-FEC group (P = 0.58). Main NCI grade 3/4 toxicities included anemia, neutropenia, rash/desquamation, and vomiting in both arms. There was one case of grade 3 pneumonitis in the TR-FEC arm. No grade 3/4 stomatitis occurred. CONCLUSION: The addition of everolimus to paclitaxel was well tolerated. Everolimus downregulated mTOR signaling but downregulation of mTOR at 48 h did not correlate with 12-week RR in the TR-FEC group. CLINICAL TRIAL NUMBER: NCT00499603.

Long-term treatment efficacy in primary inflammatory breast cancer by hormonal receptor- and HER2-defined subtypes.

BACKGROUND: Subtypes defined by hormonal receptor (HR) and HER2 status have not been well studied in inflammatory breast cancer (IBC). We characterized clinical parameters and long-term outcomes, and compared pathological complete response (pCR) rates by HR/HER2 subtype in a large IBC patient population. We also compared disease-free survival (DFS) and overall survival (OS) between IBC patients who received targeted therapies (anti-hormonal, anti-HER2) and those who did not. PATIENTS AND METHODS: We retrospectively reviewed the records of patients diagnosed with IBC and treated at MD Anderson Cancer Center from January 1989 to January 2011. Of those, 527 patients had received neoadjuvant chemotherapy and had available information on estrogen receptor (ER), progesterone receptor (PR), and HER2 status. HR status was considered positive if either ER or PR status was positive. Using the Kaplan-Meier method, we estimated median DFS and OS durations from the time of definitive surgery. Using the Cox proportional hazards regression model, we determined the effect of prognostic factors on DFS and OS. Results were compared by subtype. RESULTS: The overall pCR rate in stage III IBC was 15.2%, with the HR-positive/HER2-negative subtype showing the lowest rate (7.5%) and the HR-negative/HER2-positive subtype, the highest (30.6%). The HR-negative, HER2-negative subtype (triple-negative breast cancer, TNBC) had the worst survival rate. HR-positive disease, irrespective of HER2 status, had poor prognosis that did not differ from that of the HR-negative/HER2-positive subtype with regard to OS or DFS. Achieving pCR, no evidence of vascular invasion, non-TNBC, adjuvant hormonal therapy, and radiotherapy were associated with longer DFS and OS. CONCLUSIONS: Hormone receptor and HER2 molecular subtypes had limited predictive and prognostic power in our IBC population. All molecular subtypes of IBC had a poor prognosis. HR-positive status did not necessarily confer a good prognosis. For all IBC subtypes, novel, specific treatment strategies are needed in the neoadjuvant and adjuvant settings.

Functional proteomics characterization of residual triple-negative breast cancer after standard neoadjuvant chemotherapy.

BACKGROUND: In this study, we used functional proteomics to determine the molecular characteristics of residual triple receptor-negative breast cancer (TNBC) patients after neoadjuvant systemic chemotherapy (NCT) and their relationship with patient outcomes in order to identify potential targets for therapy. PATIENTS AND METHODS: Protein was extracted from 54 residual TNBCs, and 76 proteins related to breast cancer signaling were measured by reverse phase protein arrays (RPPAs). Univariable and multivariable Cox proportional hazard models were fitted for each protein. Survival outcomes were estimated by the Kaplan-Meier product limit method. Training and cross validation were carried out. The coefficients estimated from the multivariable Cox model were used to calculate a risk score (RS) for each sample. RESULTS: Multivariable analysis using the top 25 proteins from univariable analysis at a false discovery rate (FDR) of 0.3 showed that AKT, IGFBP2, LKB1, S6 and Stathmin were predictors of recurrence-free survival (RFS). The cross-validation model was reproducible. The RS model calculated based on the multivariable analysis was -1.1086 × AKT + 0.2501 × IGFBP2 - 0.6745 × LKB1+1.0692 × S6 + 1.4086 × stathmin with a corresponding area under the curve, AUC = 0.856. The RS was an independent predictor of RFS (HR = 3.28, 95%CI = 2.07-5.20, P < 0.001). CONCLUSIONS: We found a five-protein model that independently predicted RFS risk in patients with residual TNBC disease. The PI3 K pathway may represent potential therapeutic targets in this resistant disease.

Pathologic complete response to neoadjuvant chemotherapy with trastuzumab predicts for improved survival in women with HER2-overexpressing breast cancer.

BACKGROUND: We sought to determine the prognostic value of pathologic response to neoadjuvant chemotherapy with concurrent trastuzumab. PATIENTS AND METHODS: Two hundred and twenty-nine women with HER2/neu (HER2)-overexpressing breast cancer were treated with neoadjuvant chemotherapy plus trastuzumab between 2001 and 2008. Patients were grouped based on pathologic complete response (pCR, n = 114) or less than pCR (

The prognostic impact of age in patients with triple-negative breast cancer.

The purpose of this study was to assess the prognostic impact of age in patients with triple-negative breast cancer (TNBC). 1,732 patients with primary TNBC were analyzed. Five age cohorts (≤30, 31-40, 41-50, 51-60, and >60 years) at diagnosis were correlated with clinical/pathological parameters. Univariate and multivariate analyses were used to examine the effect of age on disease-free (DFS), distant disease-free (DDFS), and overall survival (OS). In patients with TNBC, increasing age at diagnosis was inversely correlated with tumor grade (P < 0.0001); likelihood of being non-Caucasian (P = 0.0001); likelihood of getting chemotherapy (P < 0.0001); and positively correlated with DFS (P = 0.0003); DDFS (P < 0.0001); and OS (P < 0.0001). The median DFS for patients 31-40 and older than 60 years was 4 years [95 % confidence interval (95 % CI) 2-5] and 8 years (95 % CI 5-14, respectively, P = 0.0003). The DDFS and OS were also statistically significantly shorter for younger patients. In multivariate analysis, tumor size, nodal stage, tumor grade, and age remained significant independent prognostic variables. Clinical characteristics of TNBC differ by age group, patients ≤40 years have poorer survival despite more aggressive systemic therapy.

Functional proteomics characterization of residual breast cancer after neoadjuvant systemic chemotherapy.

BACKGROUND: The purpose of this study was to determine the functional proteomic characteristics of residual breast cancer and hormone receptor (HR)-positive breast cancer after neoadjuvant systemic chemotherapy, and their relationship with patient outcomes. METHODS: Reverse phase protein arrays of 76 proteins were carried out. A boosting approach in conjunction with a Cox proportional hazard model defined relapse predictors. A risk score (RS) was calculated with the sum of the coefficients from the final model. Survival outcomes and associations of the RS with relapse were estimated. An independent test set was used to validate the results. RESULTS: Test (n = 99) and validation sets (n = 79) were comparable. CoxBoost revealed a three-biomarker (CHK1pS345, Caveolin1, and RAB25) and a two-biomarker (CD31 and Cyclin E1) model that correlated with recurrence-free survival (RFS) in all residual breast cancers and in HR-positive disease, respectively. Unsupervised clustering split patients into high- and low risk of relapse groups with different 3-year RFS (P ≤ 0.001 both). RS was a substantial predictor of RFS (P = 0.0008 and 0.0083) after adjustment for other substantial characteristics. Similar results were found in validation sets. CONCLUSIONS: We found models that independently predicted RFS in all residual breast cancer and in residual HR-positive disease that may represent potential targets of therapy in this resistant disease.

Defining biomarkers to predict sensitivity to PI3K/Akt/mTOR pathway inhibitors in breast cancer.

BACKGROUND: Identification and validation of biomarkers is increasingly important for the integration of novel targeted agents in the treatment of cancer. The phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway represents a promising therapeutic target in breast carcinoma, and inhibitors targeting different nodes of the PI3K/Akt/mTOR axis are in development. Identification of biomarkers to help select patients who are most likely to benefit from these treatments is an essential unmet need. DESIGN: MEDLINE and international conference abstracts were searched for evidence of markers of sensitivity to PI3K/Akt/mTOR pathway inhibitors in breast cancer patients and preclinical models. RESULTS: Preclinical evidence suggests that PI3K/Akt/mTOR pathway aberrations, notably in PIK3CA, may identify a subpopulation of patients with breast cancer who preferentially respond to PI3K/Akt/mTOR inhibitors. However, additional markers are needed to identify all patients with de novo sensitivity to PI3K/Akt/mTOR pathway inhibition. Early clinical studies to validate these biomarkers have as yet been inconclusive. CONCLUSIONS: Prospective, adequately designed and powered clinical trials are needed to test candidate biomarkers of sensitivity to PI3K/Akt/mTOR pathway inhibitors in patients with breast cancer, and to determine whether certain PI3K/Akt/mTOR pathway inhibitors are more appropriate in different subtypes depending on the pattern of molecular alteration.

Multifocality and multicentricity in breast cancer and survival outcomes.

BACKGROUND: The clinicopathological characteristics and the prognostic significance of multifocal (MF) and multicentric (MC) breast cancers are not well established. PATIENTS AND METHODS: MF and MC were defined as more than one lesion in the same quadrant or in separate quadrants, respectively. The Kaplan-Meier product limit was used to calculate recurrence-free survival (RFS), breast cancer-specific survival (BCSS), and overall survival (OS). Cox proportional hazards models were fit to determine independent associations of MF/MC disease with survival outcomes. RESULTS: Of 3924 patients, 942 (24%) had MF (n = 695) or MC (n = 247) disease. MF/MC disease was associated with higher T stages (T2: 26% versus 21.6%; T3: 7.4% versus 2.3%, P < 0.001), grade 3 disease (44% versus 38.2%, P < 0.001), lymphovascular invasion (26.2% versus 19.3%, P < 0.001), and lymph node metastases (43.1% versus 27.3%, P < 0.001). MC, but not MF, breast cancers were associated with a worse 5-year RFS (90% versus 95%, P = 0.02) and BCSS (95% versus 97%, P = 0.01). Multivariate analysis shows that MF or MC did not have an independent impact on RFS, BCSS, or OS. CONCLUSIONS: MF/MC breast cancers were associated with poor prognostic factors, but were not independent predictors of worse survival outcomes. Our findings support the current TNM staging system of using the diameter of the largest lesion to assign T stage.

Metaplastic sarcomatoid carcinoma of the breast appears more aggressive than other triple receptor-negative breast cancers.

Metaplastic sarcomatoid carcinoma (MSC) of the breast is usually triple receptor (ER, PR, and HER2) negative and is not currently recognized as being more aggressive than other triple receptor-negative breast cancers. We reviewed archival tissue sections from surgical resection specimens of 47 patients with MSC of the breast and evaluated the association between various clinicopathologic features and patient survival. We also evaluated the clinical outcome of MSC patients compared to a control group of patients with triple receptor-negative invasive breast carcinoma matched for patient age, clinical stage, tumor grade, treatment with chemotherapy, and treatment with radiation therapy. Factors independently associated with decreased disease-free survival among patients with stage I-III MSC of the breast were patient age > 50 years (P = 0.029) and the presence of nodal macrometastases (P = 0.003). In early-stage (stage I-II) MSC, decreased disease-free survival was observed for patients with a sarcomatoid component comprising ≥ 95% of the tumor (P = 0.032), but tumor size was the only independent adverse prognostic factor in early-stage patients (P = 0.043). Compared to a control group of triple receptor-negative patients, patients with stage I-III MSC had decreased disease-free survival (two-sided log rank, P = 0.018). Five-year disease-free survival was 44 ± 8% versus 74 ± 7% for patients with MSC versus triple receptor-negative breast cancer, respectively. We conclude that MSC of the breast appears more aggressive than other triple receptor-negative breast cancers.

Identifying factors that impact survival among women with inflammatory breast cancer.

BACKGROUND: The objective of this retrospective study was to determine factors impacting survival among women with inflammatory breast cancer (IBC). METHODS: The Surveillance, Epidemiology and End Results Registry (SEER) was searched to identify women with stage III/IV IBC diagnosed between 2004 and 2007. IBC was identified within SEER as T4d disease as defined by the sixth edition of the American Joint Committee on Cancer. The Kaplan-Meier product-limit method was used to describe inflammatory breast cancer-specific survival (IBCS). Cox models were fitted to assess the multivariable relationship of various patient and tumor characteristics and IBCS. RESULTS: Two thousand three hundred and eighty-four women with stage IIIB/C and IV IBC were identified. Two-year IBCS among women with stage IIIB, IIIC and IV disease was 81%, 67% and 42%, respectively (P < 0.0001). In the multivariable model, patients with stage IIIB disease and those with stage IIIC disease had a 63% [hazard ratio (HR) 0.373, 95% confidence interval (CI) 0.296-0.470, P < 0.001] and 31% (HR 0.691, 95% CI 0.512-0.933, P = 0.016) decreased risk of death from IBC, respectively, compared with women with stage IV disease. Other factors significantly associated with decreased risk of death from IBC included low-grade tumors, being of white/other race, undergoing surgery, receiving radiation therapy and hormone receptor-positive disease. Among women with stage IV disease, those who underwent surgery of their primary had a 51% decreased risk of death compared with those who did not undergo surgery (HR = 0.489, 95% CI 0.339-0.704, P < 0.0001). CONCLUSIONS: Although IBC is an aggressive subtype of locally advanced breast cancer, it is heterogeneous with various factors affecting survival. Furthermore, our results indicate that a subgroup of women with stage IV IBC may benefit from aggressive combined modality management.

Modeling ductal carcinoma in situ: a HER2-Notch3 collaboration enables luminal filling.

A large fraction of ductal carcinoma in situ (DCIS), a non-invasive precursor lesion of invasive breast cancer, overexpresses the HER2/neu oncogene. The ducts of DCIS are abnormally filled with cells that evade apoptosis, but the underlying mechanisms remain incompletely understood. We overexpressed HER2 in mammary epithelial cells and observed growth factor-independent proliferation. When grown in extracellular matrix as three-dimensional spheroids, control cells developed a hollow lumen, but HER2-overexpressing cells populated the lumen by evading apoptosis. We demonstrate that HER2 overexpression in this cellular model of DCIS drives transcriptional upregulation of multiple components of the Notch survival pathway. Importantly, luminal filling required upregulation of a signaling pathway comprising Notch3, its cleaved intracellular domain and the transcriptional regulator HES1, resulting in elevated levels of c-MYC and cyclin D1. In line with HER2-Notch3 collaboration, drugs intercepting either arm reverted the DCIS-like phenotype. In addition, we report upregulation of Notch3 in hyperplastic lesions of HER2 transgenic animals, as well as an association between HER2 levels and expression levels of components of the Notch pathway in tumor specimens of breast cancer patients. Therefore, it is conceivable that the integration of the Notch and HER2 signaling pathways contributes to the pathophysiology of DCIS.

Phosphoproteomic mass spectrometry profiling links Src family kinases to escape from HER2 tyrosine kinase inhibition.

Despite the initial effectiveness of the tyrosine kinase inhibitor lapatinib against HER2 gene-amplified breast cancers, most patients eventually relapse after treatment, implying that tumors acquire mechanisms of drug resistance. To discover these mechanisms, we generated six lapatinib-resistant HER2-overexpressing human breast cancer cell lines. In cells that grew in the presence of lapatinib, HER2 autophosphorylation was undetectable, whereas active phosphoinositide-3 kinase (PI3K)-Akt and mitogen-activated protein kinase (MAPK) were maintained. To identify networks maintaining these signaling pathways, we profiled the tyrosine phosphoproteome of sensitive and resistant cells using an immunoaffinity-enriched mass spectrometry method. We found increased phosphorylation of Src family kinases (SFKs) and putative Src substrates in several resistant cell lines. Treatment of these resistant cells with Src kinase inhibitors partially blocked PI3K-Akt signaling and restored lapatinib sensitivity. Further, SFK mRNA expression was upregulated in primary HER2+ tumors treated with lapatinib. Finally, the combination of lapatinib and the Src inhibitor AZD0530 was more effective than lapatinib alone at inhibiting pAkt and growth of established HER2-positive BT-474 xenografts in athymic mice. These data suggest that increased Src kinase activity is a mechanism of lapatinib resistance and support the combination of HER2 antagonists with Src inhibitors early in the treatment of HER2+ breast cancers in order to prevent or overcome resistance to HER2 inhibitors.

Quantitative proteomic analysis in breast cancer.

Much progress has recently been made in the genomic and transcriptional characterization of tumors. However, historically the characterization of cells at the protein level has suffered limitations in reproducibility, scalability and robustness. Recent technological advances have made it possible to accurately and reproducibly portray the global levels and active states of cellular proteins. Protein microarrays examine the native post-translational conformations of proteins including activated phosphorylated states, in a comprehensive high-throughput mode, and can map activated pathways and networks of proteins inside the cells. The reverse-phase protein microarray (RPPA) offers a unique opportunity to study signal transduction networks in small biological samples such as human biopsy material and can provide critical information for therapeutic decision-making and the monitoring of patients for targeted molecular medicine. By providing the key missing link to the story generated from genomic and gene expression characterization efforts, functional proteomics offer the promise of a comprehensive understanding of cancer. Several initial successes in breast cancer are showing that such information is clinically relevant.

Stability of HER2-positive status in breast carcinoma: a comparison between primary and paired metastatic tumors with regard to the possible impact of intervening trastuzumab treatment.

BACKGROUND: To date, the stability of human epidermal growth factor receptor 2 (HER2)-positive primary breast carcinomas during disease progression and the role of intervening trastuzumab treatment in the loss of HER2-positive status in paired metastases remain under-investigated. MATERIALS AND METHODS: Sixty-six patients with HER2-positive primary carcinoma and paired metastasis were evaluated. We examined the overall agreement of the HER2 status and compared the status agreement between 38 trastuzumab-treated patients and 28 trastuzumab-naive control patients. The impact of chemotherapy, endocrine therapy, metastatic site (locoregional or distant), and time to relapse (≥5 or <5 years) on the HER2 status change was assessed. RESULTS: Fifty-six (84.9%) patients had HER2 status agreement between paired tumors; 10 patients had HER2-positive-to-negative conversion. The agreement rate in the trastuzumab-treated group and in the control group was comparable (86.8% versus 82.1%) (P = 0.858). Chemotherapy, endocrine therapy, metastatic site, and time to relapse did not significantly affect HER2 stability in either group. In the discordant tumor pairs, variations in testing methods and borderline scores were common. CONCLUSIONS: HER2-positive status remained unchanged in most paired metastases. Loss of HER2-positive status did not seem to be affected by trastuzumab treatment. Differences in testing and interpretation may account for the discordance in some cases.