Abstract P4-13-14: Time on treatment of everolimus, fulvestrant, and capecitabine for the treatment of HR+/HER2- metastatic breast cancer: A retrospective claims study in the US

Background:

Treatment guidelines for hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC) recommend extending the time on treatment (TOT) of endocrine therapy (ET) prior to the initiation of chemotherapy (CT) to avoid its serious side effects and preserve patients' quality of life. Everolimus-based therapy (EVE), fulvestrant monotherapy (FUL mono), and capecitabine monotherapy (CAP mono) are among the latest ET and CT agents approved for the treatment of HR+/HER2- mBC in the US. This retrospective claims analysis compared TOT among HR+/HER2- mBC patients who received EVE versus those who received FUL mono or CAP mono respectively.

Methods:

Postmenopausal women with HR+/HER2- mBC who initiated ≥ 1 new line of therapy for mBC between 7/20/2012 (the approval date of EVE, the latest of all three therapies) and 3/31/2014 (which allowed for ≥ 3 months of potential follow-up) after a non-steroidal aromatase inhibitor were identified from the MarketScan and PharMetrics databases (2002Q1-2014Q2) using an algorithm adapted from the literature. Treatment discontinuation was defined as a treatment gap of ≥ 60 days. Patients' lines of therapies were classified into mutually-exclusive regimen groups (i.e., EVE, FUL mono, and CAP mono) and followed until discontinuation of the line of therapy, end of insurance eligibility, or data cut-off (06/30/2014). Patients who did not discontinue their treatment were censored at the end of follow-up. TOT was compared between EVE versus FUL mono and versus CAP mono using Kaplan-Meier (K-M) analyses with log-rank tests and multivariable Cox models adjusting for the line of therapy and differences in patient characteristics, including age, insurance type, de novo vs non-de-novo mBC, prior use of CT for mBC, sites of metastases (e.g., bone, brain, and visceral), and Charlson comorbidity index.

Results:

Across the first four lines of therapies for mBC, a total of 940 EVE, 953 FUL mono, and 721 CAP mono regimens were included. Based on the different lines of therapies, the K-M estimators of median TOT ranged from 5.5 to 7.2 months for EVE, 4.9 to 8.4 months for FUL mono, and 3.5 to 6.0 months for CAP mono.

Table 1. Comparison of TOT between EVE, FUL mono, and CAP mono by line of therapy Median TOT (months) EVEFUL monoCAP monoLine 16.28.43.5*Line 26.25.64.6*Line 37.25.3*6.0*Line 45.54.95.1**indicates p-value <0.05 for pairwise log-rank tests in comparison with EVE.

Pooling all lines of therapies, EVE was associated with significantly longer TOT compared to FUL mono (multivariable-adjusted hazard ratio [HR] = 0.87, 95% confidence interval [CI]: 0.76-0.99) or CAP mono (multivariable-adjusted HR = 0.73, 95% CI: 0.64-0.83). Similar results were observed in each line of therapy.

Conclusions:

This real-world US claims study of postmenopausal women with HR+/HER2- mBC showed that patients receiving EVE experienced significantly longer TOT than those receiving FUL mono or CAP mono, suggesting a comparative advantage of EVE in extending the duration of ET.

Citation Format: Li N, Hao Y, Kageleiry A, Peeples M, Fang A, Koo V, Guérin A. Time on treatment of everolimus, fulvestrant, and capecitabine for the treatment of HR+/HER2- metastatic breast cancer: A retrospective claims study in the US. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-13-14.

Abstract P2-08-20: Clinical outcomes among HR+/HER2- metastatic breast cancer patients with multiple metastatic sites

Background:

Hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2-) is the most common type of metastatic breast cancer (mBC). While overall the prognosis among these patients is poor with short progression-free survival (PFS) and overall survival (OS), those with multiple metastatic sites (multiple mets) may have even worse clinical outcomes due to multiple organ involvement. This real-world study examined clinical outcomes among HR+/HER2- mBC patients with multiple mets.

Methods:

In this retrospective chart review, a sample of postmenopausal women with HR+/HER2- mBC was collected from community-based oncology practices in the US. Patients were required to have failed a non-steroidal aromatase inhibitor and later initiated a new treatment (defined as the index therapy) for mBC between July 1, 2012 and April 15, 2013. Patients were classified into two mutually exclusive groups: multiple mets or single metastatic site (single met), based on the number of non-lymph-node metastatic sites at index therapy initiation. PFS, time on treatment (TOT), and OS were compared between the two study groups using Kaplan-Meier analyses with log-rank tests and multivariable Cox proportional hazards models adjusting for baseline characteristics, including age, race, insurance, mBC type, and months from initiation of last adjuvant endocrine therapy to mBC diagnosis, index therapy type, index therapy line, adjusted Charlson comorbidity index (CCI), Eastern Cooperative Oncology Group (ECOG) performance status, and prior chemotherapy for mBC. Patients without an event were censored at the last follow-up. In addition, separate Cox proportional hazard models were conducted including an interaction term between line of therapy and study group to assess the impact of multiple mets on clinical outcomes across different lines of therapy.

Results:

A total of 408 patients in the single met group and 291 patients in the multiple mets group were included. Patients with multiple mets had worse ECOG performance status and a higher rate of prior chemotherapy use for mBC compared with patients in the single met group. Relative to patients with single met, patients with multiple mets were associated with significantly shorter PFS (log-rank test p<0.001, hazard ratio (HR)=1.68, 95% confidence interval (CI): 1.32-2.14), TOT (log-rank test p<0.001, HR=1.37, 95% CI: 1.09-1.72) and OS (log-rank test p<0.001, HR=1.71, 95% CI: 1.12-2.63). Similar outcomes were observed in each line of therapy.

Table 1. Multivariable -adjusted comparisons of PFS, TOT, and OS between patients with multiple mets and single met by line of therapy PFSTOTOSMultiple mets vs. single metHR (95% CI)p-valueHR (95% CI)p-valueHR (95% CI)p-valueLine of therapy 11.51 (1.04,2.19)0.030*1.22 (0.86,1.73)0.2561.94 (1.06,3.56)0.032*Line of therapy 21.79 (1.17,2.74)0.008*1.50 (1.02,2.21)0.042*2.35 (1.03,5.38)0.043*Line of therapy 3+1.82 (1.18,2.83)0.007*1.46 (0.97,2.21)0.0721.03 (0.48,2.20)0.936*P < 0.05

Conclusion:

Among HR+/HER2- mBC patients, those with multiple mets had significantly worse clinical outcomes, highlighting substantial disease burden and unmet need for more efficacious treatment for these patients.

Citation Format: Xie J, Hao Y, Li N, Lin PL, Ohashi E, Koo V, Wu EQ. Clinical outcomes among HR+/HER2- metastatic breast cancer patients with multiple metastatic sites. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-20.

Abstract P4-13-13: Real-world effectiveness of everolimus versus endocrine monotherapy or chemotherapy in HR+/HER2- metastatic breast cancer patients with liver metastasis or multiple metastatic sites

Background:

Liver metastasis and multiple metastatic sites are associated with higher risk of progression or death among women with hormone receptor-positive, human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer (mBC). Traditional treatments, like endocrine monotherapy (ET mono) or chemotherapy (CT), have limited effectiveness in these high-risk patients. Everolimus-based therapy (EVE) is a new treatment option with different mechanism of action. This study examined the real-world comparative effectiveness of EVE vs. ET mono or CT in patients with liver metastasis or multiple metastatic sites.

Methods:

A sample of postmenopausal women with HR+/HER2- mBC was obtained through a retrospective chart review of community-based oncology practices in the US. All patients initiated EVE, ET mono, or CT (defined as the index therapy) for mBC between July 2012 and April 2013 after the failure of a non-steroidal aromatase inhibitor. Patients with liver metastasis and those with multiple metastatic sites (i.e., ≥2 non-lymph-node metastases) at the index therapy initiation were analyzed separately. In each group, progression-free survival (PFS) and time on treatment (TOT) were compared between EVE vs. ET mono or CT, respectively, using Kaplan-Meier analyses with log-rank tests and Cox proportional hazards models adjusting for patient and disease characteristics, such as age, mBC type, performance status, tumor burden, and prior treatment. Patients without an event were censored at the last follow-up.

Results:

A total of 202 patients had liver metastasis, including 82 treated with EVE, 49 with ET mono, and 71 with CT. EVE patients had more severe mBC than ET mono patients and less severe mBC than CT patients, as indicated by proportion of patients receiving prior CT for mBC and tumor burden. Compared with ET mono, EVE was associated with significantly longer PFS (log-rank test p=0.049; hazard ratio (HR)=0.48, 95% confidence interval (CI): 0.27-0.87) and TOT (log-rank test p=0.054, HR=0.49, 95% CI: 0.28-0.86). Similarly, compared with CT, EVE was associated with significantly longer PFS (log-rank test p=0.024, HR=0.76, 95% CI: 0.44-1.32) and TOT (log-rank test p<0.001, HR=0.35, 95% CI: 0.22-0.55).

A total of 265 patients had multiple metastatic sites, including 100 treated with EVE, 79 with ET mono, and 86 with CT. Similarly, EVE patients had more severe mBC than ET mono patients and less severe mBC than CT patients, as indicated by tumor burden. Compared with ET mono, EVE was associated with significantly longer PFS (log-rank test p=0.043, HR=0.62, 95% CI: 0.41-0.95) and TOT (log-rank test p=0.054, HR=0.64, 95% CI: 0.42-0.97). Compared with CT, EVE was also associated with longer PFS (log-rank test p=0.004, HR=0.60, 95% CI: 0.39-0.92) and TOT (log-rank test p<0.001, HR=0.36, 95% CI: 0.24-0.53).

Conclusion:

In this retrospective chart review of HR+/HER2- mBC patients, EVE was associated with significantly longer PFS and TOT compared with ET mono or CT in high-risk patients with liver metastasis or multiple metastatic sites.

Citation Format: Li N, Hao Y, Lin PL, Koo V, Ohashi E, Wu EQ, Xie J. Real-world effectiveness of everolimus versus endocrine monotherapy or chemotherapy in HR+/HER2- metastatic breast cancer patients with liver metastasis or multiple metastatic sites. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-13-13.

Zoledronic acid suppresses callus remodeling but enhances callus strength in an osteoporotic rat model of fracture healing

MINI-ABSTRACT

In this study, we demonstrated that the use of zoledronic acid does not impair fracture healing, but results in superior callus size and resistance at the fracture site, which could be the consequence of a lower rate of bone turnover due to its anti-catabolic effect.

OBJECTIVE

To investigate the effect of inhibition of bone remodeling by the bisphosphonate, zoledronic acid, on callus properties in an osteoporotic rat model of fracture healing.

METHODS

Ovariectomized (OVX) rats were randomly divided into four treatment groups (n=24 per group): saline control (CNT); and three systemic zoledronic acid-injected groups (0.1mg/kg), administered 1 day (ZOLD1), 1 week (ZOLW1), and 2 weeks (ZOLW2) after fracture. Rats were killed at either 6 or 12 weeks postoperatively. Postmortem analyses included radiography, microcomputed tomography, histology, histomorphometry, biomechanical tests, and nanoindentation tests.

RESULTS

Treatment with zoledronic acid led to a significant increase in trabecular bone volume within the callus, as well as in callus resistance, compared to those in the saline control rats; delayed administration (ZOLW2) reduced intrinsic material properties, including ultimate stress and elastic modulus, and microarchitecture parameters, including bone volume/total volume (BV/TV), trabecular thickness (Tb.Th), and connectivity density (Conn.D), compared with ZOLD1 at 12 weeks after surgery. OVX had a negative effect on the progression of endochondral ossification at 6 weeks. Zoledronic acid administration at an early stage following fracture may bind to early callus, and thus not affect subsequent callus formation and endochondral ossification, while delayed administration (ZOLW2) mildly suppresses bony callus remodeling.

CONCLUSION

The superior results obtained with zoledronic acid (ZOLD1, ZOLW1, and ZOLW2) compared to CNT in terms of callus size and resistance could be the consequence of a lower rate of bone turnover at the fracture site due to the anti-catabolic effect of zoledronic acid. Mild suppression of callus remodeling by delayed administration did not impair the initial phase of the fracture healing process.

Association between matrix metalloproteinase gene polymorphisms and development of ischemic stroke

We investigated the association between MMP2 rs243865, MMP3 rs3025058 and MMP9 rs3918242 polymorphisms and development of ischemic stroke in a Chinese population. Between January 2012 and May 2014, a total of 317 patients with ischemic stroke and 317 health control subjects were enrolled into our study. The MMP2 rs243865, MMP3 rs3025058 and MMP9 rs3918242 polymorphisms were analyzed using polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). By multivariate logistic regression analysis, we found that individuals carrying with the CC genotype and the TC+CC genotype of MMP9 rs3918242 were associated with a significantly increased risk of ischemic stroke when compared with the TT genotype, and the ORs (95% CI) was 5.47 (2.64-12.38) and 1.55 (1.08-2.24), respectively. The TC+CC genotype of MMP9 rs3918242 was associated with an elevated risk of ischemic stroke in tobacco smokers, and the OR (95% CI) was 2.03 (1.11-3.74). In conclusion, our study suggests that MMP9 rs3918242 polymorphism is correlated with an elevated risk of ischemic stroke, and this gene polymorphism has interaction with tobacco smoking in the risk of ischemic stroke.

Well plate-based perfusion culture device for tissue and tumor microenvironment replication

There are significant challenges in developing in vitro human tissue and tumor models that can be used to support new drug development and evaluate personalized therapeutics. The challenges include: (1) working with primary cells which are often difficult to maintain ex vivo, (2) mimicking native microenvironments from which primary cells are harvested, and (3) the lack of culture devices that can support these microenvironments to evaluate drug responses in a high-throughput manner. Here we report a versatile well plate-based perfusion culture device that was designed, fabricated and used to: (1) ascertain the role of perfusion in facilitating the expansion of human multiple myeloma cells and evaluate drug response of the cells, (2) preserve the physiological phenotype of primary murine osteocytes by reconstructing the 3D cellular network of osteocytes, and (3) circulate primary murine T cells through a layer of primary murine intestine epithelial cells to recapitulate the interaction of the immune cells with the epithelial cells. Through these diverse case studies, we demonstrate the device's design features to support: (1) the convenient and spatiotemporal placement of cells and biomaterials into the culture wells of the device; (2) the replication of tissues and tumor microenvironments using perfusion, stromal cells, and/or biomaterials; (3) the circulation of non-adherent cells through the culture chambers; and (4) conventional tissue and cell characterization by plate reading, histology, and flow cytometry. Future challenges are identified and discussed from the perspective of manufacturing the device and making its operation for routine and wide use.

Psychrophilic fungi from the world's roof

During a survey of cold-adapted fungi in alpine glaciers on the Qinghai-Tibet Plateau, 1 428 fungal isolates were obtained of which 150 species were preliminary identified. Phoma sclerotioides and Pseudogymnoascus pannorum were the most dominant species. Psychrotolerant species in Helotiales (Leotiomycetes, Ascomycota) were studied in more detail as they represented the most commonly encountered group during this investigation. Two phylogenetic trees were constructed based on the partial large subunit nrDNA (LSU) to infer the taxonomic placements of these strains. Our strains nested in two well-supported major clades, which represented Tetracladium and a previously unknown lineage. The unknown lineage is distant to any other currently known genera in Helotiales. Psychrophila gen. nov. was therefore established to accommodate these strains which are characterised by globose or subglobose conidia formed from phialides on short or reduced conidiophores. Our analysis also showed that an LSU-based phylogeny is insufficient in differentiating strains at species level. Additional analyses using combined sequences of ITS+TEF1+TUB regions were employed to further investigate the phylogenetic relationships of these strains. Together with the recognisable morphological distinctions, six new species (i.e. P. antarctica, P. lutea, P. olivacea, T. ellipsoideum, T. globosum and T. psychrophilum) were described. Our preliminary investigation indicates a high diversity of cold-adapted species in nature, and many of them may represent unknown species.

Intrinsic and extrinsic risk factors for nonunion after nonoperative treatment of midshaft clavicle fractures

BACKGROUND

The optimal treatment of midshaft clavicle fractures remains controversial. Nonunion is usually considered to be an uncommon complication following a nonoperatively treated clavicle fracture.

HYPOTHESIS

Not every midshaft clavicular fractures shares the same risk of developing nonunion after nonoperative treatment. The present study was performed to identify the intrinsic and extrinsic independent factors that are independently predictive of nonunion in patients with midshaft clavicular fractures after nonoperative treatment.

MATERIALS AND METHODS

We performed a retrospective study of a series of 804 patients (391 men and 413 women with a median age of 51.3 years) with a radiographically confirmed midshaft clavicle fracture, which was treated nonoperatively. There were 96 patients who underwent nonunion. Putative intrinsic (patient-related) and extrinsic (injured-related) risk factors associated with nonunion were determined with the use of bivariate and multivariate statistical analyses.

RESULTS

By bivariate analysis, the risk of nonunion was significantly increased by several intrinsic risk factors including age, sex, and smoking and extrinsic risk factors including displacement of the fracture and the presence of comminution (P<0.05 for all). On multivariate analysis, smoking (OR=4.16, 95% CI: 1.01-14.16), fracture displacement (OR=7.81, 95% CI: 2.27-25.38) and comminution of fracture (OR=3.86, 95% CI: 1.16-13.46) were identified as independent predictive factors.

CONCLUSION

The risk factors for nonunion after nonoperative treatment of midshaft clavicle fractures are multifactorial. Smoking, fracture displacement and comminution of fracture are independent predictors for an individual likelihood of nonunion. Further studies are still required to evaluate these factors in the future.

LEVEL OF EVIDENCE

Level III, case-control study.

Highly ordered core–shell CoFe2O4–BiFeO3 nanocomposite arrays from dimension confined phase separation and their interfacial magnetoelectric coupling properties

With dimension confinement, highly ordered core–shell CoFe₂O₄–BiFeO₃ nanocomposite arrays were obtained from the self-assembly phase separation.

Illusions and cloaks for surface waves

Ever since the inception of Transformation Optics (TO), new and exciting ideas have been proposed in the field of electromagnetics and the theory has been modified to work in such fields as acoustics and thermodynamics. The most well-known application of this theory is to cloaking, but another equally intriguing application of TO is the idea of an illusion device. Here, we propose a general method to transform electromagnetic waves between two arbitrary surfaces. This allows a flat surface to reproduce the scattering behaviour of a curved surface and vice versa, thereby giving rise to perfect optical illusion and cloaking devices, respectively. The performance of the proposed devices is simulated using thin effective media with engineered material properties. The scattering of the curved surface is shown to be reproduced by its flat analogue (for illusions) and vice versa for cloaks.

Lenses on curved surfaces

This Letter presents a theory that allows graded index lenses to be mapped onto arbitrary rotationally symmetric curved surfaces. Examples of the Luneburg and Maxwell fish-eye lens are given, for numerous surfaces, always resulting in isotropic permittivity requirements. The performance of these lenses is initially illustrated with full-wave simulations utilizing a waveguide structure. A transformation of the refractive index profiles is then performed to design surface-wave lenses, where the dielectric layer is not only isotropic but also homogenous, demonstrating the applicability and ease of fabrication.

Fabrication of single-crystal few-layer graphene domains on copper by modified low-pressure chemical vapor deposition

Few-layer graphene domains are fabricated by modified LPCVD on Cu and the growth mechanism is schematically shown in the figure.

Assessments of jaw bone density at implant sites using 3D cone-beam computed tomography

OBJECTIVE

To assess the bone density of dental implant sites using CBCT and Simplant software, and establish a quantitative ranges for each bone quality classification according to the classification of bone quality proposed by Lekholm and Zarb.

PATIENTS AND METHODS

128 patients' jaw bone were scanned by CBCT, the images were reconstructed by the Simplant software. The bone density of 236 potential implant sites was measured and the results were recorded using Hounsfield units (HU)．The data was analyzed with SPSS 19.0 software package for Mann-Whitney U test.

RESULTS

The anterior mandible mean bone density was (679.6 ± 141.67) HU > anterior maxilla, (460.25 ± 136.42) HU and posterior mandible, (394.4 ± 128.37) HU > posterior maxilla, (229.62 ± 144.48) HU. Quantitative parameters ranged of the bone density according to CBCT as follows: Lekholm and Zarb classification Type D4 was less than 200 HU, Type D2 and Type D3 were more than 200HU and less than 600 HU, and Type D1 was more than 600 HU.

CONCLUSIONS

Anterior mandible has the highest mean bone density and posterior maxilla has the lowest mean bone density．It is, therefore, proposed that an objective classification which confirms the importance of a site-specific bone tissue evaluation prior to implant installation.

Coffee, tea, and the risk of hip fracture: a meta-analysis

The present meta-analysis shows no clear association between coffee consumption and the risk of hip fractures. There was a nonlinear association between tea consumption and the risk of hip fracture. Compared to no tea consumption, drinking 1-4 cups of tea daily was associated with a lower risk of hip fracture.

INTRODUCTION

Prospective cohort and case-control studies have suggested that coffee and tea consumption may be associated with the risk of hip fracture; the results have, however, been inconsistent. We conducted a meta-analysis to assess the association between coffee and tea consumption and the risk of hip fracture.

METHODS

We performed systematic searches using MEDLINE, EMBASE, and OVID until February 20, 2013, without limits of language or publication year. Relative risks (RRs) with 95% confidence intervals (CI) were derived using random-effects models throughout all analyses. We conducted categorical, dose-response, heterogeneity, publication bias, and subgroup analyses.

RESULTS

Our study was based on 195,992 individuals with 9,958 cases of hip fractures from 14 studies, including six cohort and eight case-control studies. The pooled RRs of hip fractures for the highest vs. the lowest categories of coffee and tea consumption were 0.94 (95% CI 0.71-1.17) and 0.84 (95% CI 0.66-1.02), respectively. For the dose-response analysis, we found evidence of a nonlinear association between tea consumption and the risk of hip fracture (p(nonlinearity) < 0.01). Compared to no tea consumption, 1-4 cups of tea per day may reduce the risk of hip fracture by 28% (0.72; 95% CI 0.56-0.88 for 1-2 cups/day), 37% (0.63; 95% CI 0.32-0.94 for 2-3 cups/day), and 21% (0.79; 95% CI 0.62-0.96 for 3-4 cups/day).

CONCLUSIONS

We found no significant association between coffee consumption and the risk of hip fracture. A nonlinear association emerged between tea consumption and the risk of hip fracture; individuals drinking 1-4 cups of tea per day exhibited a lower risk of hip fractures than those who drank no tea. The association between 5 daily cups of tea, or more, and hip fracture risk should be investigated.

Abstract P4-12-04: Initial treatment and survival among elderly breast cancer patients by receipt of human epidermal growth factor receptor 2-targeted therapy: An analysis of US national data 2006-2009

BACKGROUND: There are few studies of initial treatment and survival among elderly, newly diagnosed breast cancer (BC) patients stratified by receipt of human epidermal growth factor receptor 2- (HER2-) targeted therapy.

METHODS: Using linked Surveillance, Epidemiology, and End Results (SEER) and Medicare claims and enrollment data from 2006-2009, women aged 65+ years with an incident diagnosis of BC (index date) in 2007 and no prior history of any other cancer were identified and followed to evaluate initial treatment and survival. Study patients were required to have continuous enrollment from 1 year before index (baseline period) through the end of the data window, disenrollment or death, whichever came first. Patients were classified as having received HER2-targeted therapy if they had any claim indicating trastuzumab or lapatinib following diagnosis. Demographics, initial treatment (within 4 months of diagnosis), and survival (proportion of patients who died during the study period) were evaluated by receipt of HER2-targeted therapy (and by age and stage among those who received HER2-targeted therapy). Kaplan-Meier (KM) survival curves and survival at 36 months were estimated by stage. Treatment included surgery, radiation, chemotherapy, biologic, and hormone therapy, and was evaluated among patients with &gt; 2 months of follow-up.

RESULTS: Among 11,238 female BC patients, 510 received HER2-targeted therapy (99.8% trastuzumab, 2.5% lapatinib) and 10,728 did not. Those who received HER2-targeted therapy were slightly younger at diagnosis (mean age 73 vs. 76, P&lt;0.01) and less likely to have positive estrogen receptor (ER+; 52.7 vs. 85.1%, P&lt;0.01) and progesterone receptor (PR+; 37.8 vs. 72.6%, P&lt;0.01) status. They were also more likely to be diagnosed at later stages (Stage III: 23.3 vs. 7.4%; Stage IV: 10.6 vs. 4.9%; P&lt;0.01). Patients with HER2-targeted therapy were less likely to receive surgery (87.5 vs. 91.9%; P = 0.06), radiation (39.0 vs. 43.2%; P&lt;0.01), or hormone therapy (6.9 vs. 16.8%, P&lt;0.01), but more likely to receive chemotherapy (69.8 vs. 12.6%, P&lt;0.01). Mortality was similar between the two groups (15.3% for HER2-targeted therapy vs. 16.1% for non HER2-targeted therapy, P = 0.71). Among patients receiving HER2-targeted therapy, increased age (P&lt;0.01) and later stage (P&lt;0.01) were associated with higher mortality. Older patients were more likely to receive hormone therapy (P = 0.02) and less likely to receive chemotherapy (P = 0.02) and surgery (P = 0.08). Patients in later stages were less likely to receive surgery (P&lt;0.01) or radiation (P&lt;0.01) and more likely to receive chemotherapy (P = 0.01) or hormone therapy (P = 0.05).

CONCLUSIONS: Elderly, newly diagnosed BC patients who received HER2-targeted therapy were younger than those who did not received HER2-targeted therapy. Initial treatment patterns varied between the two groups, but survival outcomes were similar. Among patients in the HER2-targeted therapy group, treatment characteristics also differed by disease stage and age.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-04.

Abstract P3-06-11: Disease and treatment characteristics of a large insured female population with advanced or metastatic breast cancer by receipt of HER2-targeted agents

This retrospective administrative claims study of women diagnosed with advanced or metastatic breast cancer (BC) compared clinical histories and BC treatment by receipt of HER2- targeted agents (2TA), disease stage, and age group.

Women ≥ 18 years, diagnosed with stage III or IV BC were selected from the 2008-2012 Truven Health MarketScan databases using ICD-9-CM codes on non-diagnostic medical claims corresponding to BC and local or distant metastases; date of first metastasis was the index date. Patients were followed until the earliest of end of enrollment, inpatient death or 12/31/2012. Those with &lt;12 months continuous enrollment (CE) or non-BC primary cancers pre-index, or HIV or pregnancy anytime were excluded. 2TA was defined as ≥1 medical or pharmacy claim for trastuzumab or lapatinib in the pre- or post-index periods. Study cohorts were women ± 2TA use, 2TA users with stage III and IV BC, and 2TA users age 18-44, 45-64, or 65+ at index. Index demographics, pre-index BC and clinical histories, and post-index BC treatments were compared using t-tests, one-way ANOVA, and chi-square statistics.

Of 30,660 eligible women, 14.4% received 2TA at sometime. Compared to non-2TA patients those with 2TA were younger (mean (SD) age 55 (11) vs. 59 (13) years; p≤0.001) and had significantly lower comorbidity burden. While pre-index BC was similar (48% each), 2TA patients had higher rates of pre-index BC surgery (20% vs. 17%), adjuvant/neoadjuvent chemotherapy (74% vs. 53%), radiation treatment (12% vs. 10%), and lower non-2TA biologics use (0% vs. 3%), all p&lt;0.005. Of the 2TA cohort with pre-index BC, 58% used 2TA pre-index. Also among 2TA patients, 57% had Stage III BC at index and 18% were 18-44, 68% 45-64 and 15% 65+. Pre-index BC diagnosis differed by index BC stage (30% III vs. 73% IV) and increased with age (44% 18-44, 48% 45-64, 54% 65+), both p&lt;0.001.

Of those with ≥ 3 months CE post-index, 2TA users had higher rates, p&lt;0.001 of BC surgery (53% vs. 47%), radiation (65% vs. 54%) and non-2TA antineoplastic treatment (AT: 89% vs. 83%), compared to non-2TA patients. Of those treated, 2TA users had a higher rate of chemotherapy use (85% vs. 58%), but lower use rates of hormone therapy (56% vs. 78%) and non-2TA biologics (5% vs. 8%), all p&lt;0.001. Receipt of post-index BC surgery was greater among 2TA stage III than stage IV patients (78% vs. 19%) and decreased with age (62% 18-44, 53% 45-64, 42% 65+), both p&lt;0.001. Post-index, stage III 2TA patients were more likely (p&lt;0.001) to have radiation therapy (72% vs. 56%), use 2TA agents post-index (97% vs. 91%), and other AT (92% vs. 84%) compared to stage IV 2TA patients. Radiation declined in the 2TA cohort post-index with increasing age (70%, 65%, 61%, p&lt;0.001). 2TA and AT use also declined with increasing age but these did not reach statistical significance.

Receipt of 2TA (vs. non-2TA) was significantly associated with younger age and receipt of pre- and post- BC treatments. Clinical history and BC treatment differences between these cohorts partly reflect differential treatment patterns of HER2- positive and HER2- negative BC patients. Treatment characteristics for the 2TA cohort differ by disease stage and age group.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-11.

Abstract P3-06-09: Survival among patients with hormone receptor positive (HR+)/human epidermal growth factor receptor 2 negative (HER2-) advanced breast cancer: A real-world observational study

Background: Little is known about real-world outcomes for patients with HR+/HER2- advanced breast cancer. This study examined mortality outcomes, and in particular variations across patients with different stages of cancer and different sequencing of endocrine and chemotherapy treatments.

Methods: This retrospective study linked medical and pharmacy claims (2008-2012) from a large national US health plan with a proprietary clinical cancer database containing physician-reported clinical data on patients with breast cancer. Patients included in the study had HR+ and HER2- status, and had stage III (S3) or IV (S4) cancer at initial diagnosis, or had developed metastases following initial diagnosis (MET). The first date of diagnosis of advanced cancer or the first date of metastases following initial diagnosis was designated as the index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled in the health plan were retained. A 3-month baseline period assessed prior treatment; a variable follow-up (until disenrollment or 31 Oct 2012) assessed patterns of endocrine and chemotherapy treatments following the index date. Patient mortality was identified via a combination of Social Security mortality data and patient hospital discharge status from claims data. Chi-square tests compared proportions and t-tests compared means.

Results: The study population included 263 S3, 71 S4, and 317 MET patients. Average age at index date was 51.9 years for S3, 54.4 years for SIV, and 52.8 years for MET patients (P = 0.080). Over the entire observable follow-up, 3.4% of S3 (17 per 1000 patient-years), 22.5% of S4 (119 per 1000 patient years), and 10.7% of MET patients (22 per 1000 patient years) died (P≤0.010 for comparisons). Mortality over the 1-year after index date was 1.1%, 12.7%, and 5.1% in the S3, S4, and MET groups respectively (P&lt;0.001). Patients who died in the first year after index date survived on average until 5.8 months (S3), 4.5 months (S4), and 7.3 months (MET) following the metastatic index date. Among MET patients, mean time to death from initial breast cancer diagnosis was 35.7 months for MET patients without endocrine treatment prior to chemotherapy (n = 157), and 76.1 months for other MET patients (n = 160) (P = 0.002). For S4 patients without endocrine treatment prior to chemotherapy (n = 34), patients survived an average of 10.0 months from initial advanced breast cancer diagnosis while the remaining S4 patients (n = 37) survived an average of 14.8 months.

Conclusions: Among patients with HR+/HER2- advanced breast cancer, mortality rates varied by stage of disease, and length of survival varied across patients pre-treated with endocrine therapy prior to chemotherapy compared with other patients. Further investigation of drivers behind differences in mortality may reveal the extent to which initial disease severity and sequencing of chemotherapy and endocrine therapy drive these variations.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-09.

Abstract P3-06-10: All-cause resource use among elderly breast cancer patients by receipt of human epidermal growth factor receptor 2-targeted therapy: An analysis of US national data 2006-2009

BACKGROUND: There are few recent studies of all-cause resource use among elderly, newly diagnosed breast cancer (BC) patients by receipt of human epidermal growth factor receptor 2- (HER2-) targeted therapy.

METHODS: Using linked Surveillance, Epidemiology, and End Results (SEER) and Medicare claims and enrollment data from 2006-2009, women aged 65+ years with an incident diagnosis of BC (index date) in 2007 and no prior history of any other cancer were identified and followed to evaluate all-cause resource use. Study patients were required to have continuous enrollment from 1 year before index (baseline period) through the end of the data window, disenrollment or death, whichever came first. Patients were classified as having received HER2-targeted therapy if they had any claim indicating trastuzumab or lapatinib following diagnosis. Demographics and all-cause resource use (hospitalizations, hospital days, outpatient visits, physician/provider services, prescription drug use, skilled nursing facility [SNF] care, home health care, hospice care, and durable medical equipment) were evaluated by receipt of HER2-targeted therapy (and by stage and age among those treated with HER2-targeted therapy).

RESULTS: Among 11,238 female BC patients, 510 received HER2-targeted therapy (99.8% trastuzumab, 2.5% lapatinib) and 10,728 did not. Duration of follow-up was longer for the HER2- targeted therapy group (mean: 28.0 vs. 27.2 months, P = 0.06). Patients receiving HER2-targeted therapy were more likely to be hospitalized during follow-up (72.4% vs. 57.8%, P&lt;0.01), though they had fewer mean per-patient-per-month (PPPM) hospital days (0.38 vs. 0.49, P&lt;0.01). Almost all patients had an outpatient visit (100.0% and 97.3%, P&lt;0.01) and a physician/provider visit (100.0% and 99.6%, P = 0.42) during follow-up, though patients receiving HER2-targeted therapy experienced greater PPPM service use (mean outpatient visits 1.08 vs. 0.69, P&lt;0.01; mean physician/provider services 3.91 vs. 2.79, P&lt;0.01). Similar proportions of patients had prescription drug (61.2% vs. 57.7%, P = 0.12), SNF care (14.3% vs. 14.5%, P = 0.95), and hospice care (both 8.2%, P = 1.00) use. Among patients treated with HER2-targeted therapy, those with later stage cancer were more likely to receive SNF (8.6% [Stage I], 11.8% [Stage II], 16.8% [Stage III], 27.8% [Stage IV]; P&lt;0.01), home health (20.7%, 39.6%, 50.4%, 50.0%; P&lt;0.01), and hospice care (0.0%, 0.5%, 15.1%, 31.5%; P&lt;0.01), and had higher mean PPPM hospital days (0.23, 0.32, 0.47, 0.73; P&lt;0.01). Patients treated with HER2-targeted therapy aged 75+ were more likely to be hospitalized (64.7% [65-69], 73.3% [70-74], 79.4% [75+]; P = 0.01) and to receive SNF (12.4%, 10.0%, 21.3%; P = 0.01), home health (31.2%, 35.6%, 51.9%; P&lt;0.01), and hospice care (5.3%, 4.4%, 15.6%; P&lt;0.01).

CONCLUSIONS: Patients receiving HER2-targeted therapy were more likely to be hospitalized than those not receiving HER2-targeted therapy, although with fewer mean PPPM hospital days. Outpatient and physician visits also were more frequent in the HER2-targeted therapy group. Among those receiving HER2-targeted therapy, resource use was higher among those diagnosed at later stages and advanced ages.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-10.

Abstract PD3-5: Survival benefit conferred by the androgen receptor is lost in aromatase inhibitor treated breast cancer

Aromatase Inhibitors have proven to be most effective in the treatment of post-menopausal breast cancer. Their mode of action is to inhibit the synthesis of estrogen (estrone) by the aromatase enzyme Cyp 19 thereby blocking ligand-dependent activation of the estrogen receptor. What has not been addressed to date is how cells that are deprived of estrogen, may potentially, adapt to the more androgenic environment resulting from long-term treatment with AI therapy. Research from our lab has identified the homeobox protein, HOXC11, to be an indicator of poor response to endocrine therapy and development of metastasis. To further our understanding of HOXC11 and its role in the development of endocrine-resistance and metastatic spread we undertook an RNA-seq experiment to identify its target genes in resistant breast cancer. This analysis identified PSAP, IFIT1 and HSP90AA1. Both PSAP (an androgen agonist) and HSP90AA1 (AR chaperone) are closely associated with AR which led to further investigation into the role of HOXC11 in the development of steroidal adaptability in Letrozole-resistant breast cancer. We hypothesize that HOXC11 regulated expression of PSAP results in oncogenic activation of AR in an AI resistant setting. Our findings have shown that AI-resistant cell lines in vitro have significantly elevated levels of AR and that loss of HOXC11 results in concommitant decrease in AR mRNA. In AI resistance expression of HOXC11 results in upregulation/stabilization of AR by PSAP thus enabling the tumour to adapt to use androgenic steroids for cell proliferation. The anti-androgen, Bicalutamide, reduces cell proliferation and cell motility in AI resistant cell lines. Survival analysis of AR in a TMA (n = 488) indicates that AR confers a survival benefit in the tamoxifen treated population. This protective effect is diminished in patients receiving AI therapy and is reflected in the altered Hazard Ratio of AR from the total population (HR: 0.485) to the AI treated cohort (HR: 1.197). Secreted PSAP was readily detectable in breast cancer patient serum and associates significantly with expression of HOXC11 in matched patient tissue (∼20). PSAP is associated with poor response to endocrine therapy and metastatic spread of prostate cancer and as it is secreted it could potentially be used to monitor patients on AI who might benefit from dual targeted therapy treatment.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD3-5.

Abstract P3-06-08: Patterns of health care utilization and costs by chemotherapy and endocrine therapy sequencing among patients with hormone receptor positive (HR+)/HER2- negative advanced breast cancer

Background: Little is known about health care costs and health services utilization of patients with HR+/HER2- advanced breast cancer, particularly in relation to the order in which patient receive endocrine and chemotherapy treatments.

Methods: A proprietary database with physician-reported clinical data on patients with breast cancer was linked to medical and pharmacy claims (2008-2012) from a national US health plan. Patients included in the study had HR+ and HER2- status. Advanced cancer included stage III or IV (SIV) at initial diagnosis, or developed metastases following initial diagnosis. The first date of advanced cancer diagnosis or date of metastases following initial diagnosis was designated as the index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled were retained. A 3-month baseline period assessed prior treatment; variable follow-up (until disenrollment or 31 Oct 2012) assessed patterns of endocrine and chemotherapy treatments following index date. All-cause and cancer-specific health care utilization and paid costs were assessed over 12-months following index date. Costs were calculated as per-patient-per-month (PPPM), and utilization measured as rates per patient-month. Cancer-related medication costs included drug costs for endocrine, chemotherapy, targeted therapy, and treatments for pain or chemotherapy-induced nausea/ vomiting. In addition, costs for anti-cancer systemic therapies (chemotherapy, endocrine, and targeted therapy) were calculated PPPM including costs for medication administration.

Results: Of 651 study patients, 65% initiated chemotherapy prior to initiating endocrine therapy (CH). Remaining patients (OT) either had no chemotherapy (n = 132 endocrine only, n = 16 neither endocrine nor chemotherapy), or used endocrine therapy prior to chemotherapy (n = 77). Compared with OT, the CH group had more office (4.04 vs. 2.68 visits, P&lt;0.001) and outpatient hospital visits (3.08 vs. 2.10 visits, P&lt;0.001). In addition, 56% of CH vs. 41% of OT had inpatient hospital admissions during the follow-up (P&lt;0.001; rate ratio 0.97, P = NS). Similarly, 60% of CH patients were admitted to emergency rooms vs. 51% of OT (P = 0.033; rate ratio 1.01, P = NS). Mean total all-cause health care costs varied ($11,525 CH vs. $8,196 OT, P&lt;0.001). The largest source of difference in costs were office visits (mean $3,257 CH vs. $1,896 OT, P&lt;0.001), and outpatient hospital ($5,813 CH vs. $3,721 OT, P&lt;0.001). Cancer-related costs comprised the majority of costs (mean $10,249 CH vs. $7,118 OT, P&lt;0.001). The CH group had higher mean cancer-related medication costs than the OT group ($2,051 vs. $1,405 respectively, P = 0.040). Overall mean anti-cancer systemic therapy costs (including administration) were higher in the CH than OT group ($2,934 vs. $1,875, P = 0.012).

Conclusions: Among HR+/HER2- advanced breast cancer patients, health care utilization and costs were higher for patients who initiated chemotherapy prior to endocrine therapy compared to other patients. Further investigation of the drivers behind these differences is warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-06-08.

Abstract P1-14-03: Chemotherapy and endocrine therapy treatment patterns among patients with hormone receptor positive (HR+)/HER2 negative advanced breast cancer

Background: National Comprehensive Cancer Network breast cancer guidelines suggest optimized sequencing of endocrine therapy prior to chemotherapy use for patients who are HR+/HER2-, but it is unclear how those recommendations translate into clinical practice. This study examined sequencing of endocrine and chemotherapy treatment to better understand real-world treatment patterns for HR+/HER2- advanced breast cancer.

Methods: This retrospective study examined physician-reported clinical data on patients with breast cancer (BC) linked to medical and pharmacy claims (2008-2012) from a large national US health plan. Patients included in the study had HR+ and HER2- status. Advanced cancer cohorts included patients who were stage IV (SIV) at initial diagnosis, or who developed metastases following initial diagnosis (MET). The first date of diagnosis of advanced cancer or date of metastases following initial diagnosis was designated as index date. Health plan enrollment for 3 months pre- and ≥12-months post- index date was required; patients who died within 12 months after index date and were continuously enrolled were retained. A 3-month baseline period assessed prior treatment; variable post-index follow-up (until disenrollment or Oct 2012) assessed patterns of endocrine and chemotherapy.

Results: Of 317 MET patients, 50% initiated chemotherapy after index date without prior endocrine treatment (CH). Remaining patients (OT) used only endocrine therapy (30%), endocrine therapy prior to chemotherapy (17%), or neither endocrine nor chemotherapy (3%). Compared with OT patients, CH patients were younger (50 vs. 55 years, P&lt;0.001) and progressed faster to metastasis after initial BC diagnosis (243 vs. 1633 days, P&lt;0.001). Although CH patients in the MET group had slightly higher comorbidity prior to their metastatic index date, they had lower levels of any non-lymph node metastases (14% vs. 48%, P&lt;0.001) and visceral metastases (5% vs. 16%, P = 0.001) during follow-up. Among MET patients, 92% of CH patients initiated endocrine therapy during follow-up; endocrine therapy started a mean of 235 days after metastatic index date, compared with a mean starting date for chemotherapy of 41 days post-metastatic index date. In the MET group, 55% of CH later initiated treatment with aromatase inhibitors, compared with 64% of OT patients (P = 0.104). Results were similar in newly diagnosed SIV (n = 71) group: 48% had no evidence of endocrine treatment prior to initiating chemotherapy, and remaining patients used only endocrine therapy (27%), had endocrine therapy prior to chemotherapy (21%), or neither therapy (4%).

Conclusions: In this population of patients with HR+/HER2- advanced breast cancer, a large proportion initiated chemotherapy without prior endocrine therapy. This group of patients might otherwise benefit from a longer progression free period with tolerable toxicity from endocrine therapy. Further investigation of whether a subgroup of these patients started chemotherapy in the adjuvant setting is warranted. For those starting chemotherapy without prior endocrine therapy, understanding treatment sequencing and patient characteristics will help illuminate the extent to which patterns adhere to NCCN guidelines.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-14-03.

Perfect surface wave cloaks

This Letter presents a method for making an uneven surface behave as a flat surface. This allows an object to be concealed (cloaked) under an uneven portion of the surface, without disturbing the wave propagation on the surface. The cloaks proposed in this Letter achieve perfect cloaking that only relies upon isotropic radially dependent refractive index profiles, contrary to those previously published. In addition, these cloaks are very thin, just a fraction of a wavelength in thickness, yet can conceal electrically large objects. While this paper focuses on cloaking electromagnetic surface waves, the theory is also valid for other types of surface waves. The performance of these cloaks is simulated using dielectric filled waveguide geometries, and the curvature of the surface is shown to be rendered invisible, hiding any object positioned underneath. Finally, a transformation of the required dielectric slab permittivity was performed for surface wave propagation, demonstrating the practical applicability of this technique.

Fas-associated factor 1 plays a negative regulatory role in the antibacterial immunity of Locusta migratoria

Insect immune responses are precisely regulated to maintain immune balance. In this study, the Fas-associated factor 1 (FAF1) gene of Locusta migratoria manilensis, a homologue of the caspar gene that functions as a specific negative regulator in the antibacterial immunity pathway, was cloned. Gene expression analysis showed that FAF1 was expressed throughout the developmental stages and in all tested tissues, but its transcription levels varied significantly. Thus, FAF1 appears to be tightly regulated and is probably involved in multiple physiological processes. In addition, the antimicrobial peptide gene prolixicin was cloned and characterized. After bacterial challenge, prolixicin was rapidly up-regulated, whereas FAF1 was markedly down-regulated. This result was consistent with the observation that prolixicin was hyperactivated when FAF1 was suppressed by RNA interference. Moreover, after bacterial infection, the survival rate of FAF1-knockdown locusts was much higher than that of the wild-type. Taken together, these findings strongly suggest that FAF1 shares a similar function as caspar in Drosophila and may be involved in the negative regulation of antibacterial immunity in locusts.

Clinicopathological study of distant metastases of salivary adenoid cystic carcinoma

Most studies of the clinicopathological characteristics and prognosis of patients with distant metastasis of salivary adenoid cystic carcinoma (SACC) have used small patient samples. To further explore this issue, a descriptive and prognostic study of 467 patients with SACC who were treated from 1963 to 2009 was conducted at a single institution. One hundred and forty-five patients (31.0%) had distant metastases. At least 20% of patients who presented with the early-stage disease and no recurrence developed distant metastasis. The overall 5-, 10-, and 20-year survival rates were 85.6%, 67.4%, and 50.4%, respectively, for patients without distant metastasis, and 69.1%, 45.7%, and 14.3%, respectively, for patients with distant metastasis. The median survival time after distant metastasis was 36 months (range 1-112 months). The prognosis was similar between patients who received treatment for metastasis and those who did not. Patients who were diagnosed with early-stage disease and without local recurrence of the primary tumours could also develop distant metastases. The biological characteristics of adenoid cystic carcinoma were different from those of squamous cell carcinoma. At present, the effectiveness of treatment for distant metastases is not ideal and further research is needed.

Protein interaction and microRNA network analysis in osteoarthritis meniscal cells

Osteoarthritis is the most common form of arthritis among elderly adults. Herein, we performed protein-protein interaction (PPI) and miRNA network analysis to evaluate the global correlation between miRNA regulation and the PPI network in human osteoarthritis. Our results showed that desmoplakin (DSP), cystatin A (CSTA), calmodulin 1, tyrosine kinase endothelial, insulin-like growth factor 1 (IGF-1), IGF-binding protein 7 (IGFBP7), syndecan 1 (SDC1), ephrin type-A receptor 4, and PDZ and LIM domain protein 1 were associated with osteoarthritis. Among these proteins, DSP and CSTA interaction and IGF-1, IGFBP7 and SDC1 interaction were observed in our PPI network. Furthermore, these potential target proteins were also linked with individual miRNA in the network. Our findings shed light on the PPIs and mechanisms by which miRNA may regulate the protein interaction network in osteoarthritis, which might provide theoretical support for further studies aimed at discovering new therapeutic strategies.

Abstract P6-04-21: AIB1 expression specifically predicts breast cancer patient response to aromatase inhibitor therapy

Aromatase inhibitors (AI) have evolved over the last decade into an effective therapeutic regime for postmenopausal women with primary or advanced breast cancer. Despite their remarkable success in the clinic, intrinsic resistance to therapy occurs in a proportion of patients, while other patients who respond initially to treatment will relapse with recurrent disease. Previous studies suggest that this may be due, at least in part to estrogen receptor (ER) hypersensitivity.

We undertook ER ChIPseq analysis on AI resistant cell model and data for this suggests that ER transcriptional regulation alone may not be responsible for the development of the resistant phenotype. We examined the role of the established ER coactivator protein AIB1. AIB1 has previously been associated with initiation of breast cancer and resistance to endocrine therapy. In tamoxifen treated patients, expression of AIB1 in conjunction with an activated HER2 cascade has been associated with treatment resistance and early disease recurrence. By contrast, we have observed that AIB1 alone can predict response to AIs. In our TMA the expression of AIB1 associated with disease recurrence (p = 0.025) and reduced disease free survival time (p = 0.0471) in patients treated with AIs as first-line therapy. Reflecting increased growth factor activity reported in AI resistance, AIB1 expression associated with the growth factor second messenger signaling proteins, p-Src and pERK1/2, but not the receptor HER2. These results suggest that AIB1 may utilize additional transcription factors other than ER to drive endocrine resistance. Additionally, we show that AIB1 is highly expressed in AI resistant metastases; therefore, monitoring AIB1 expression may be useful to screen for disease progression and detect disease advancement before metastases appear.

Our studies of cell line models of AI resistance suggest that AIB1 may play a functional role in aggressive, migratory, phenotype of AI resistance. We have generated cell line models of resistance to letrozole (LetR) and anastrozole (AnaR). Our resistance models have higher levels of AIB1 and have increased migratory capacity. Interestingly, knockdown of AIB1 reduces the migratory capacity of the resistant cells.

Furthermore, we have observed that AIB1 regulation of ER target genes is selectively enhanced in AI resistant cells in a promoter specific context. AIB1 recruitment to ER target genes such as pS2 and Myc becomes insensitive to letrozole. By contrast, AIB1 recruitment to cyclinD1 retained letrozole sensitivity. Our evidence suggests that steroidal regulation of transcription factors such as Jun and Fos may contribute to this promoter-specific regulation of ER target genes.

We establish a role for AIB1 in AI-resistant breast cancer and describe a new mechanism of ERalpha/AIB1 gene regulation which could contribute to the development of an aggressive tumour phenotype. We provide evidence of a central role for AIB1 in regulating selective ER transcriptional activity and driving tumour recurrence in AI treated patients. Tackling the emerging problem of AI resistance in a timely fashion will enable us to tailor existing therapies and improve outcome in specific patient groups before disease recurrence becomes a clinical issue.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-21.

Effect of abiraterone acetate on fatigue in patients with metastatic castration-resistant prostate cancer after docetaxel chemotherapy

BACKGROUND

Fatigue is a common, debilitating side-effect of prostate cancer and its treatment. Patient-reported fatigue was evaluated as part of COU-AA-301, a randomized, placebo-controlled, phase III trial of abiraterone acetate and prednisone versus placebo and prednisone in metastatic castration-resistant prostate cancer (mCRPC) patients after docetaxel chemotherapy. This is the first phase III study in advanced prostate cancer to evaluate fatigue outcomes using a validated fatigue-specific instrument.

PATIENTS AND METHODS

The Brief Fatigue Inventory (BFI) questionnaire was used to measure patient-reported fatigue intensity and fatigue interference with activities of daily life. All analyses were conducted using prespecified responder definitions of clinically meaningful changes.

RESULTS

A total of 797 patients were randomized to abiraterone acetate and prednisone, and 398 were randomized to placebo and prednisone. Compared with prednisone alone, in patients with clinically significant fatigue at baseline, abiraterone acetate and prednisone significantly increased the proportion of patients reporting improvement in fatigue intensity (58.1% versus 40.3%, P = 0.0001), improved fatigue interference (55.0% versus 38.0%, P = 0.0075), and accelerated improvement in fatigue intensity (median 59 days versus 194 days, P = 0.0155).

CONCLUSIONS

In patients with mCRPC progressing after docetaxel chemotherapy, abiraterone acetate and prednisone yielded clinically meaningful improvements in patient-reported fatigue compared with prednisone alone.

Overexpression of heat shock protein 70 and its relationship to intestine under acute heat stress in broilers: 1. Intestinal structure and digestive function

The objective of this study was to investigate the relationship between heat shock protein 70 (HSP70) overexpression and intestinal structure and digestive function in heat-stressed broilers. In total, 240 male broilers were injected intraperitoneally with l-(1)-glutamine (0.75 mg/kg of BW) or quercetin (5 mg/kg of BW). Twenty-four hours later, they were heat-stressed for 0, 2, 3, 5, and 10 h, respectively, under 36 ± 1°C. The HSP70 protein and mRNA expression were obviously elevated at 3 h of heat stress, and glutamine induced the overexpression of HSP70 in the jejunal mucosa at different heat-stress times (P < 0.01). No significant change of jejunal villus height, crypt, and villus height:crypt ratio were observed after heat stress, and there were no effects of HSP70 overexpression on intestinal morphology under heat stress. The overexpression of HSP70 significantly increased alkaline phosphatase activity at 3 h of heat stress (P < 0.01). There was a strong correlation between HSP70 expression and the digestive enzyme activity (P ≤ 0.001). The overexpression of HSP70 significantly increased the amylase, lipase, and trypsin activity under heat stress (P < 0.001). These results demonstrated that glutamine was a good HSP70 enhancer to establish an HSP70 overexpression model. Although the overexpression of HSP70 did not change intestinal morphology conditions, it significantly increased broiler digestive enzyme activity under heat stress.