Genomic characterization of HER2-positive breast cancer and response to neoadjuvant trastuzumab and chemotherapy-results from the ACOSOG Z1041 (Alliance) trial.

Background: HER2 (ERBB2) gene amplification and its corresponding overexpression are present in 15-30% of invasive breast cancers. While HER2-targeted agents are effective treatments, resistance remains a major cause of death. The American College of Surgeons Oncology Group Z1041 trial (NCT00513292) was designed to compare the pathologic complete response (pCR) rate of distinct regimens of neoadjuvant chemotherapy and trastuzumab, but ultimately identified no difference. Patients and methods: In supplement to tissues from 37 Z1041 cases, 11 similarly treated cases were obtained from a single institution study (NCT00353483). We have extracted genomic DNA from both pre-treatment tumor biopsies and blood of these 48 cases, and performed whole genome (WGS) and exome sequencing. Coincident with these efforts, we have generated RNA-seq profiles from 42 of the tumor biopsies. Among patients in this cohort, 24 (50%) achieved a pCR. Results: We have characterized the genomic landscape of HER2-positive breast cancer and investigated associations between genomic features and pCR. Cases assigned to the HER2-enriched subtype by RNA-seq analysis were more likely to achieve a pCR compared to the luminal, basal-like, or normal-like subtypes (19/27 versus 3/15; P = 0.0032). Mutational events led to the generation of putatively active neoantigens, but were overall not associated with pCR. ERBB2 and GRB7 were the genes most commonly observed in fusion events, and genomic copy number analysis of the ERBB2 locus indicated that cases with either no observable or low-level ERBB2 amplification were less likely to achieve a pCR (7/8 versus 17/40; P = 0.048). Moreover, among cases that achieved a pCR, tumors consistently expressed immune signatures that may contribute to therapeutic response. Conclusion: The identification of these features suggests that it may be possible to predict, at the time of diagnosis, those HER2-positive breast cancer patients who will not respond to treatment with chemotherapy and trastuzumab. ClinicalTrials.gov identifiers: NCT00513292, NCT00353483.

Effects of neoadjuvant chemotherapy with or without zoledronic acid on pathological response: A meta-analysis of randomised trials.

PURPOSE: The addition of bisphosphonates to adjuvant therapy improves survival in postmenopausal breast cancer (BC) patients. We report a meta-analysis of four randomised trials of neoadjuvant chemotherapy (CT) +/- zoledronic acid (ZA) in stage II/III BC to investigate the potential for enhancing the pathological response. METHODS: Individual patient data from four prospective randomised clinical trials reporting the effect of the addition of ZA on the pathological response after neoadjuvant CT were pooled. Primary outcomes were pathological complete response in the breast (pCRb) and in the breast and lymph nodes (pCR). Trial-level and individual patient data meta-analyses were done. Predefined subgroup-analyses were performed for postmenopausal women and patients with triple-negative BC. RESULTS: pCRb and pCR data were available in 735 and 552 patients respectively. In the total study population ZA addition to neoadjuvant CT did not increase pCRb or pCR rates. However, in postmenopausal patients, the addition of ZA resulted in a significant, near doubling of the pCRb rate (10.8% for CT only versus 17.7% with CT+ZA; odds ratio [OR] 2.14, 95% confidence interval [CI] 1.01-4.55) and a non-significant benefit of the pCR rate (7.8% for CT only versus 14.6% with CT+ZA; OR 2.62, 95% CI 0.90-7.62). In patients with triple-negative BC a trend was observed favouring CT+ZA. CONCLUSION: This meta-analysis shows no impact from the addition of ZA to neoadjuvant CT on pCR. However, as has been seen in the adjuvant setting, the addition of ZA to neoadjuvant CT may augment the effects of CT in postmenopausal patients with BC.

Current perspectives on skeletal health and cancer progression across the disease continuum in breast cancer-the role of bisphosphonates.

Pre-clinical and clinical evidence suggest that bisphosphonates inhibit both bone resorption and cancer progression. New and updated analyses from several large, controlled studies in pre- and post-menopausal women with early stage breast cancer (BC) suggest that addition of bisphosphonates improves cancer-related outcomes, particularly in patients with a 'low-estrogen environment'. Further, preliminary clinical data suggest that bisphosphonate therapy may reduce circulating tumour cell numbers (a negative prognostic indicator of disease-free and overall survival) in patients with advanced/metastatic disease. These new findings warrant reconsideration of the therapeutic role of bisphosphonates in BC.

Effect of (Neo)adjuvant zoledronic acid on disease-free and overall survival in clinical stage II/III breast cancer.

BACKGROUND: Despite neoadjuvant/adjuvant chemotherapy, women with resectable stage II/III breast cancer (BC) have high risk of recurrent disease. Recent data suggest that zoledronic acid (ZOL) therapy concurrent with adjuvant treatments may improve cancer-related outcomes in patients with BC. METHODS: Disease-free survival (DFS; secondary end point) and overall survival (OS; tertiary end point) were evaluated in 119 women with stage II/III BC randomised to intravenous ZOL 4 mg every 3 weeks for 1 year or no ZOL (control) starting with the first chemotherapy cycle. RESULTS: At 61.9 months' median follow-up, there was no significant difference in recurrence or survival between study arms. However, time to recurrence or death (DFS) was significantly different between subgroups defined by oestrogen receptor (ER) status (interaction P=0.010 for DFS and 0.025 for OS). Hazard ratios (HRs) for disease recurrence and death were significantly less among patients with ER-negative (ER(-)) tumours who received ZOL vs no ZOL (DFS: HR=0.361, 95% confidence interval (CI) 0.148, 0.880; OS: HR=0.375, 95% CI 0.143, 0.985). CONCLUSION: ZOL administered with chemotherapy may improve DFS and OS in a subset of BC patients with ER(-) tumours. This study was not powered to compare subgroups of patients; thus, these findings should be considered hypothesis generating.

Quality of life over time in women diagnosed with ductal carcinoma in situ, early-stage invasive breast cancer, and age-matched controls.

Little is known about quality-of-life (QOL) differences over time between incident ductal carcinoma in situ (DCIS) and early-stage invasive breast cancer (EIBC) cases as compared with same-aged women without breast cancer (controls). We prospectively recruited and interviewed 1,096 women [16.8% DCIS, 33.3% EIBC (25.7% Stage I; and 7.6% Stage IIA), 49.9% controls; mean age 58; 23.7% non-white] at mean 6.7 weeks (T1), and 6.2 (T2), 12.3 (T3), and 24.4 months (T4) after surgery (patients) or screening mammogram (controls). We tested two hypotheses: (1) DCIS patients would report lower levels of QOL compared with controls but would report similar QOL compared with EIBC patients at baseline; and (2) DCIS patients' QOL would improve during 2-year follow-up and approach levels similar to that of controls faster than EIBC patients. We tested hypothesis 1 using separate general linear regression models for each of the eight subscales on the RAND 36-item Health Survey, controlling for variables associated with at least one subscale at T1. Both DCIS and EIBC patients reported lower QOL at T1 than controls on all subscales (each P<0.05). We tested hypothesis 2 using generalized estimating equations to examine change in each QOL subscale over time across the three diagnostic groups adjusting for covariates. By T3, physical functioning, role limitations due to physical problems, energy/fatigue, and general health each differed significantly by diagnostic group at P<0.05, because of larger differences between EIBC patients and controls; but DCIS patients no longer differed significantly from controls on any of the QOL subscales. At T4, EIBC patients still reported worse physical functioning (P=0.0001) and general health (P=0.0017) than controls, possibly because of lingering treatment effects. DCIS patients' QOL was similar to that of controls two years after diagnosis, but some aspects of EIBC patients' QOL remained lower.

Evaluation of 2-deoxy-D-glucose as a chemotherapeutic agent: mechanism of cell death.

Nutrient deprivation has been shown to cause cancer cell death. To exploit nutrient deprivation as anti-cancer therapy, we investigated the effects of the anti-metabolite 2-deoxy-D-glucose on breast cancer cells in vitro. This compound has been shown to inhibit glucose metabolism. Treatment of human breast cancer cell lines with 2-deoxy-D-glucose results in cessation of cell growth in a dose dependent manner. Cell viability as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide conversion assay and clonogenic survival are decreased with 2-deoxy-D-glucose treatment indicating that 2-deoxy-D-glucose causes breast cancer cell death. The cell death induced by 2-deoxy-D-glucose was found to be due to apoptosis as demonstrated by induction of caspase 3 activity and cleavage of poly (ADP-ribose) polymerase. Breast cancer cells treated with 2-deoxy-D-glucose express higher levels of Glut1 transporter protein as measured by Western blot analysis and have increased glucose uptake compared to non-treated breast cancer cells. From these results we conclude that 2-deoxy-D-glucose treatment causes death in human breast cancer cell lines by the activation of the apoptotic pathway. Our data suggest that breast cancer cells treated with 2-deoxy-D-glucose accelerate their own demise by initially expressing high levels of glucose transporter protein, which allows increased uptake of 2-deoxy-D-glucose, and subsequent induction of cell death. These data support the targeting of glucose metabolism as a site for chemotherapeutic intervention by agents such as 2-deoxy-D-glucose.

Rural-urban differences in radiation therapy for ductal carcinoma in-situ of the breast.

PURPOSE: Rural women in the United States are at a documented disadvantage with regard to breast cancer detection, diagnosis, and treatment and generally do not receive state-of-the-art therapy. The objective of the study was to determine if, and to what extent, rural women were less likely to receive radiation therapy (XRT) following breast conserving surgery (BCS) for ductal carcinoma in-situ (DCIS). METHODS: Our analyses were based on 1991-1996 data provided by the Surveillance, Epidemiology, and End Results (SEER) Program. Only women who were diagnosed with their first primary, microscopically confirmed DCIS breast cancer were included. BCS and XRT were defined according to SEER definitions. Multiple logistic regression was used in the analysis. RESULTS: During this time period, 6,988 women were treated with BCS for DCIS, 50.1% of whom received XRT. In multivariate analysis, rural women in general (OR = 0.58) and younger women (<65) in particular (OR = 0.38) were less likely to receive XRT. Local availability of XRT was not associated with receipt among younger women, while older women without this availability were less likely to receive XRT (OR = 0.48). CONCLUSIONS: Barriers to XRT following BCS for DCIS may be different between younger and older rural women relative to their urban counterparts.

Degradation and covalent cross-linking of glutathione reductase by hemin.

Hemin (ferriprotoporphyrin IX-chloride) can mediate the covalent cross-linking and degradation of yeast glutathione reductase. This reaction requires both NADPH and oxygen suggesting the involvement of a reduced oxygen species in the cross-linking and degradation process. During the course of the reaction the enzymatic activity of glutathione reductase is rapidly destroyed. Implications of these findings for a regulatory role of hemin in cell biology are discussed.

Hemin-mediated oxidative degradation of proteins.

Hemin, in the presence of 2-mercaptoethanol and oxygen, catalyzes the selective degradation of heme-binding proteins to small peptide fragments. Among the proteins examined, the heme-binding protein of rabbit serum (HBP-93) proved to be unusually sensitive. Myoglobin also exhibited considerable sensitivity whereas hemopexin and bovine serum albumin were only slightly susceptible to this degradative action of hemin. The reaction with HBP-93 depended upon coordination of the protein with hemin, was optimal at pH 6.5 and increased 4-fold as the temperature was elevated from 10 to 60 degrees C. The requirement for both oxygen and the reducing agent, 2-mercaptoethanol, and the partial protection of HBP-93 to degradation by catalase, superoxide dismutase, mannitol, and thiourea suggest the involvement of reduced oxygen species in the reaction. A possible role for the heme-mediated degradation of proteins in cell differentiation and other biological responses is discussed.

Hemin-mediated DNA strand scission.

Hemin (ferric protoporphyrin IX chloride) has been shown to cause strand scission in DNA in a reaction which requires the presence of oxygen and the reducing agent, 2-mercaptoethanol. In model studies, circular supercoiled plasmid DNA is converted within 30 min to the open circle and linear forms. With longer incubation times the DNA is degraded to small pieces. The reaction is markedly influenced by the addition of divalent cations; Mg2+ and Ca2+ inhibit the reaction while the transition metals Co2+, Zn2+, Ni2+, and Cu2+ promote the degradation. These observations are discussed in relation to the role of hemin in the modulation of gene expression during cell differentiation.

Role of nonhemoglobin heme accumulation in the terminal differentiation of Friend erythroleukemia cells.

The differentiation of murine erythroleukemia cells (T3C12 Friend cells) on treatment with dimethyl sulfoxide (DMSO) has been correlated with an early and extended overproduction of heme. The cessation of cell replication and the development of nuclear condensation, changes which are associated with the terminal differentiation of these cells, occur when the level of heme rises 0.1 nmol/10(6) cells over that amount which can be complexed by globin protein. A significant fraction of the excess heme is localized in the nuclei of the DMSO-treated cells. The addition of exogenous hemin facilitates the onset of terminal differentiation in the DMSO-treated T3C12 cells, whereas only the induction of globin gene expression is observed in the absence of DMSO. To study the role of heme in erythroid differentiation, a Friend cell variant (R10) has been isolated whose synthesis and accumulation of heme in response to DMSO is deficient. This variant grows logarithmically in the presence of DMSO and fails to terminally differentiate. When exogenous hemin is added, the DMSO-treated R10 cells stop replicating. In the absence of DMSO, however, hemin-treated R10 cells continue to grow and express their globin genes without exhibiting other signs of terminal differentiation. The combined results support the conclusion that both the DMSO treatment and the accumulation of excess heme are required to bring about the terminal differentiation of Friend erythroleukemia cells. Preliminary evidence is presented which suggests that in addition to the induction of heme and globin synthesis, DMSO also induces a heme activation process which is required for differentiation. The possible relationship of this process to the terminal differentiation of erythroid cells is discussed.

Control of globin gene expression by steroid hormones in differentiating Friend leukemia cells.

Low levels of dexamethasone and related glucocorticoid hormones suppress the expression of globin genes during the DMSO-induced differentiation of Friend leukemia cells. In this response, the glucocorticoids appear to act at both the transcriptional and post-transcriptional levels in that 10(-8) M dexamethasone prevents the accumulation of both globin mRNA and globin protein, whereas 10(-9) M dexamethasone allows the accumulation of normal levels of hybridizable globin mRNA but prevents the accumulation of globin protein. This suppressive action of dexamethasone is more effective with DMSO as the inducer of globin gene expression than with hemin as the inducer. In contrast to the situation with glucocorticoids, certain sex steroids (etiocholanolone, testosterone and estradiol) facilitate the expression of globin genes in DMSO-treated Friend leukemia cells. The modulation of globin gene expression by steroid hormones is achieved in DMSO-treated cells without altering the growth and morphological changes which characteristically attend the differentiation of these cells.