Lasofoxifene versus fulvestrant for ER+/HER2- metastatic breast cancer with an ESR1 mutation: results from the randomized, phase II ELAINE 1 trial

BACKGROUND

Acquired estrogen receptor alpha (ER/ESR1) mutations commonly cause endocrine resistance in ER+ metastatic breast cancer (mBC). Lasofoxifene, a novel selective ER modulator, stabilizes an antagonist conformation of wild-type and ESR1-mutated ER-ligand binding domains, and has antitumor activity in ESR1-mutated xenografts.

PATIENTS AND METHODS

In this open-label, randomized, phase II, multicenter, ELAINE 1 study (NCT03781063), we randomized women with ESR1-mutated, ER+/human epidermal growth factor receptor 2 negative (HER2-) mBC that had progressed on an aromatase inhibitor (AI) plus a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) to oral lasofoxifene 5 mg daily or IM fulvestrant 500 mg (days 1, 15, and 29, and then every 4 weeks) until disease progression/toxicity. The primary endpoint was progression-free survival (PFS); secondary endpoints were safety/tolerability.

RESULTS

A total of 103 patients received lasofoxifene (n = 52) or fulvestrant (n = 51). The most current efficacy analysis showed that lasofoxifene did not significantly prolong median PFS compared with fulvestrant: 24.2 weeks (∼5.6 months) versus 16.2 weeks (∼3.7 months; P = 0.138); hazard ratio 0.699 (95% confidence interval 0.434-1.125). However, PFS and other clinical endpoints numerically favored lasofoxifene: clinical benefit rate (36.5% versus 21.6%; P = 0.117), objective response rate [13.2% (including a complete response in one lasofoxifene-treated patient) versus 2.9%; P = 0.124], and 6-month (53.4% versus 37.9%) and 12-month (30.7% versus 14.1%) PFS rates. Most common treatment-emergent adverse events with lasofoxifene were nausea, fatigue, arthralgia, and hot flushes. One death occurred in the fulvestrant arm. Circulating tumor DNA ESR1 mutant allele fraction (MAF) decreased from baseline to week 8 in 82.9% of evaluable lasofoxifene-treated versus 61.5% of fulvestrant-treated patients.

CONCLUSIONS

Lasofoxifene demonstrated encouraging antitumor activity versus fulvestrant and was well tolerated in patients with ESR1-mutated, endocrine-resistant mBC following progression on AI plus CDK4/6i. Consistent with target engagement, lasofoxifene reduced ESR1 MAF, and to a greater extent than fulvestrant. Lasofoxifene may be a promising targeted treatment for patients with ESR1-mutated mBC and warrants further investigation.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Composite Indium Tin Oxide Nanofibers with Embedded Hematite Nanoparticles for Photoelectrochemical Water Splitting

Hematite is a classical photoanode material for photoelectrochemical water splitting due to its stability, performance, and low cost. However, the effect of particle size is still a question due to the charge transfer to the electrodes. In this work, we addressed this subject by the fabrication of a photoelectrode with hematite nanoparticles embedded in close contact with the electrode substrate. The nanoparticles were synthesized by a solvothermal method and colloidal stabilization with charged hydroxide molecules, and we were able to further use them to prepare electrodes for water photo-oxidation. Hematite nanoparticles were embedded within electrospun tin-doped indium oxide nanofibers. The fibrous layer acted as a current collector scaffold for the nanoparticles, supporting the effective transport of charge carriers. This method allows better contact of the nanoparticles with the substrate, and also, the fibrous scaffold increases the optical density of the photoelectrode. Electrodes based on nanofibers with embedded nanoparticles display significantly enhanced photoelectrochemical performance compared to their flat nanoparticle-based layer counterparts. This nanofiber architecture increases the photocurrent density and photon-to-current internal conversion efficiency by factors of 2 and 10, respectively.

Atomic and Molecular Layer Deposition of Chiral Thin Films Showing up to 99% Spin Selective Transport

Spin electronics is delivering a much desired combination of properties such as high speed, low power, and high device densities for the next generation of memory devices. Utilizing chiral-induced spin selectivity (CISS) effect is a promising path toward efficient and simple spintronic devices. To be compatible with state-of-the-art integrated circuits manufacturing methodologies, vapor phase methodologies for deposition of spin filtering layers are needed. Here, we present vapor phase deposition of hybrid organic-inorganic thin films with embedded chirality. The deposition scheme relies on a combination of atomic and molecular layer deposition (A/MLD) utilizing enantiomeric pure alaninol molecular precursors combined with trimethyl aluminum (TMA) and water. The A/MLD deposition method deliver highly conformal thin films allowing the fabrication of several types of nanometric scale spintronic devices. The devices showed high spin polarization (close to 100%) for 5 nm thick spin filter layer deposited by A/MLD. The procedure is compatible with common device processing methodologies.

Layered Si-Ti oxide thin films with tailored electrical and optical properties by catalytic tandem MLD-ALD

Oxides with well-controlled optical and electrical properties are key for numerous advances in nanotechnology, including energy, catalysis, sensors, and device applications. In this study we introduce layer-by-layer deposition of silicon–titanium layered oxide (Si–Ti LO) thin films using combined MLD-ALD methodology (M/ALD). The Si–Ti LO film deposition is achieved by acid–base catalysis establishing an overall catalytic tandem M/ALD super cycle (CT-M/ALD). The catalytic nature of the process allows relatively fast deposition cycles under mild conditions compared with the typical cycle time and conditions required for ALD processes with silane precursors. The Si–Ti LO thin films exhibit tuneable refractive index and electrical conductivities. The refractive index is set by the stoichiometry of Si- to Ti-oxide phases simply by selecting the MLD to ALD proportion in the CT-M/ALD super cycle, with low and high refractive index, respectively. Thermal treatment of Si–Ti LO thin films resulted in conductive thin films with both graphitic and Magnéli oxide phases. Enhanced conductivity and reduced onset temperature for Magnéli phase formation were obtained owing to the unique Si–Ti layer structure and stoichiometry attained by the CT-M/ALD process and facilitated by breaking of Si–C bonds and Red–Ox reactions between the Si sub-oxide and TiO₂ phases leading to the conductive Magnéli phase. Hence, the embedded amine silane functions not only for catalysing Si–Ti LO deposition but also to further promote subsequent transformations during thermal processing. This work demonstrates the concept of embedding a meta-stable organic motif by the MLD step to facilitate transformation of an oxide phase by taking advantage of precise layer-by-layer deposition of alternating phases enabled by M/ALD.

Layer-by-layer deposition of Si–Ti layered oxide thin films are obtained using catalytic tandem M/ALD methodology. The films exhibit optical (RI) and electrical conductivities by selecting the MLD to ALD proportion in the super cycle.

Chirality Nanosensor with Direct Electric Readout by Coupling of Nanofloret Localized Plasmons with Electronic Transport

The detection of enantiopurity for small sample quantities is crucial, particularly in the pharmaceutical industry; however, existing methodologies rely on specific chiral recognition elements, or complex optical systems, limiting its utility. A nanoscale chirality sensor, for continuously monitoring molecular chirality using an electric circuit readout, is presented. This device design represents an alternative real-time scalable approach for chiral recognition of small quantity samples (less than 10³ adsorbed molecules). The active device component relies on a gold nanofloret hybrid structure, i.e., a high aspect ratio semiconductor-metal hybrid nanosystem in which a SiGe nanowire tip is selectively decorated with a gold metallic cap. The tip mechanically touches a counter electrode to generate a nanojunction, and upon exposure to molecules, a metal-molecule-metal junction is formed. Adsorption of chiral molecules at the gold tip induces chirality in the localized plasmonic resonance at the electrode-tip junction and manifests in an enantiospecific current response.

Talazoparib versus chemotherapy in patients with germline BRCA1/2-mutated HER2-negative advanced breast cancer: final overall survival results from the EMBRACA trial

BACKGROUND

In EMBRACA, talazoparib prolonged progression-free survival versus chemotherapy (hazard ratio [HR] 0.542 [95% confidence interval (CI) 0.413-0.711]; P < 0.0001) and improved patient-reported outcomes (PRO) in germline BRCA1/2 (gBRCA1/2)-mutated advanced breast cancer (ABC). We report final overall survival (OS).

PATIENTS AND METHODS

This randomized phase III trial enrolled patients with gBRCA1/2-mutated HER2-negative ABC. Patients received talazoparib or physician's choice of chemotherapy. OS was analyzed using stratified HR and log-rank test and prespecified rank-preserving structural failure time model to account for subsequent treatments.

RESULTS

A total of 431 patients were entered in a randomized study (287 talazoparib/144 chemotherapy) with 412 patients treated (286 talazoparib/126 chemotherapy). By 30 September 2019, 216 deaths (75.3%) occurred for talazoparib and 108 (75.0%) chemotherapy; median follow-up was 44.9 and 36.8 months, respectively. HR for OS with talazoparib versus chemotherapy was 0.848 (95% CI 0.670-1.073; P = 0.17); median (95% CI) 19.3 months (16.6-22.5 months) versus 19.5 months (17.4-22.4 months). Kaplan-Meier survival percentages (95% CI) for talazoparib versus chemotherapy: month 12, 71% (66% to 76%)/74% (66% to 81%); month 24, 42% (36% to 47%)/38% (30% to 47%); month 36, 27% (22% to 33%)/21% (14% to 29%). Most patients received subsequent treatments: for talazoparib and chemotherapy, 46.3%/41.7% received platinum and 4.5%/32.6% received a poly(ADP-ribose) polymerase (PARP) inhibitor, respectively. Adjusting for subsequent PARP and/or platinum use, HR for OS was 0.756 (95% bootstrap CI 0.503-1.029). Grade 3-4 adverse events occurred in 69.6% (talazoparib) and 64.3% (chemotherapy) patients, consistent with previous reports. Extended follow-up showed significant overall improvement and delay in time to definitive clinically meaningful deterioration in global health status/quality of life and breast symptoms favoring talazoparib versus chemotherapy (P < 0.01 for all), consistent with initial analyses.

CONCLUSIONS

In gBRCA1/2-mutated HER2-negative ABC, talazoparib did not significantly improve OS over chemotherapy; subsequent treatments may have impacted analysis. Safety was consistent with previous observations. PRO continued to favor talazoparib.

Broad-band high-gain room temperature photodetectors using semiconductor-metal nanofloret hybrids with wide plasmonic response

Semiconducting nanowires are widely studied as building blocks for electro-optical devices; however, their limited cross-section and hence photo-response hinder the utilization of their full potential. Herein, we present an opto-electronic device for broad spectral detection ranging from the visible (VIS) to the short wavelength infra-red (SWIR) regime, using SiGe nanowires coupled to a broadband plasmonic antenna. The plasmonic amplification is obtained by deposition of a metallic nanotip at the edge of a nanowire utilizing a bottom-up synthesis technique. The metallic nanotip is positioned such that both optical plasmonic modes and electrical detection paths are coupled, resulting in a specific detectivity improvement of ∼1000 compared to conventional SiGe NWs. Detectivity and high gain are also measured in the SWIR regime owing to the special plasmonic response. Furthermore, the temporal response is improved by ∼1000. The fabrication process is simple and scalable, and it relies on low-resolution and facile fabrication steps with minimal requirements for top-down techniques.

Abstract P6-18-12: EMBRACA: Efficacy and safety of talazoparib or physician's choice of therapy in patients with advanced breast cancer and a germline BRCA1/2 mutation: A regional analysis

Background: Talazoparib (TAL) prevents DNA damage repair by inhibiting poly (ADP-ribose) polymerase (PARP) enzymes and trapping PARP on DNA, resulting in cell death in BRCA1/2-mutated cells.

Methods: EMBRACA is an open-label, randomized, 2-arm phase 3 trial in which efficacy and safety of TAL (1 mg/d) were compared with physician's choice of therapy (PCT; capecitabine, eribulin, gemcitabine, vinorelbine) in patients (pts) with locally advanced or metastatic breast cancer (ABC) and a germline BRCA mutation (gBRCAm). Outcomes were assessed by region of the world (North America [NA]; Europe [EU]; rest of world [ROW]). Progression-free survival (PFS), objective response rate (ORR), and clinical benefit rate (CBR) at 24 wks were assessed; safety was also assessed.

Results: 431 pts were randomized 2:1. Pt characteristics were well balanced, although a higher percentage of pts in ROW had more severe disease (eg, triple-negative breast cancer [TNBC], Disease-free interval [DFI]&lt;12 mo, more distant metastases, more disease sites) and were on average younger than pts in NA/EU. TAL provided improvement in PFS, ORR, and CBR in all regions vs PCT. The most common toxicities with TAL included anemia, neutropenia, thrombocytopenia, fatigue, and nausea for all regions. Alopecia was less frequent with TAL in EU/ROW. Serious adverse events for pts receiving TAL were more frequent in EU than NA/ROW. Incidences of adverse events associated with permanent treatment discontinuation in pts receiving TAL were low in all regions and generally lower than for PCT.

Table 1CategoryNA* (N=156)EU* (N=190)ROW* (N=85)Mean age, years49.049.244.2Race, %   White76.971.152.9Black5.8-3.5Asian5.8-42.4Not reported-27.4-TNBC, %424447BRCA1**, %414748BRCA2**, %595352DFI&lt;12 mo, %313444Distant metastases, %949397≥3 disease sites, %474049PFS, (hazard ratio [HR]; [95% CI]); P value0.46 [0.29-0.74] P=.00090.52 [0.33-0.80]; P&lt;.0030.57 [0.31-1.07] ;P=.08ORR (odds ratio [OR] [95% CI]); P value5.54 [2.4-16.1];P&lt;.00013.75 [1.57-9.87]; P=.0016.7 [1.61-28.39]; P=.001CBR (OR [95% CI]); P value4.71 [2.20-10.57]; P&lt;.00013.39 [1.56-7.36]; P=.00075.70 [1.70-17.13]; P=.002Hematologic AEs, %   Anemia50.558.642.6Neutropenia31.332.346.3Thrombocytopenia28.322.635.2Nonhematologic AEs, %   Fatigue59.643.650.0Nausea47.545.957.4Headache32.330.837.0Alopecia34.320.320.4Serious adverse events, %25.340.622.2Treatment discontinuation, n/N, (%)   TAL7/99 (7.1)12/133 (9.0)3/54 (5.6)PCT7/43 (16.3)3/54 (5.6)2/29 (6.9)AE, adverse event; CI, confidence interval; *NA (United States); EU (Belgium, France, Germany, Ireland, Italy, Poland, Spain, United Kingdom, Russia, Ukraine, Israel); ROW (Brazil, Korea, Australia, Taiwan).**Central laboratory.

Conclusions: In pts with gBRCAm ABC, TAL demonstrated significant improvements in clinical outcomes compared with PCT regardless of the region of the world in which they lived. However, slight differences among the regions in baseline characteristics were noted, possibly due to regional variation in diagnosis and detection of gBRCAm ABC as well as different treatment paradigms for metastatic breast cancer.

Funding: Medivation LLC, acquired by Pfizer.

Citation Format: Mina L, Lee K-H, Gonçalves A, Woodward N, Hurvitz SA, Diab S, Yerushalmi R, Goodwin A, Moreira Costa Zorzetto M, Kim S-B, Czibere A, Tudor IC, Gauthier E, Litton JK, Ettl J. EMBRACA: Efficacy and safety of talazoparib or physician's choice of therapy in patients with advanced breast cancer and a germline BRCA1/2 mutation: A regional analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-12.

Diversification of Device Platforms by Molecular Layers: Hybrid Sensing Platforms, Monolayer Doping, and Modeling

Inorganic materials such as semiconductors, oxides, and metals are ubiquitous in a wide range of device technologies owing to the outstanding robustness and mature processing technologies available for such materials. However, while the important contribution of inorganic materials to the advancement of device technologies has been well established for decades, organic-inorganic hybrid device systems, which merge molecular functionalities with inorganic platforms, represent a newer domain that is rapidly evolving at an increasing pace. Such devices benefit from the great versatility and flexibility of the organic building blocks merged with the robustness of the inorganic platforms. Given the overwhelming wealth of literature covering various approaches for modifying and using inorganic devices, this feature article selectively highlights some of the advances made in the context of the diversification of devices by surface chemistry. Particular attention is given to oxide-semiconductor systems and metallic surfaces modified with organic monolayers. The inorganic device components, such as semiconductors, metals, and oxides, are modified by organic monolayers, which may serve as either active, static, or sacrificial components. We portray research directions within the broader field of organic-inorganic hybrid device systems that can be viewed as specific examples of the potential of such hybrid device systems given their comprehensive capabilities of design and diversification. Monolayer doping techniques where sacrificial organic monolayers are introduced into semiconducting elements are reviewed as a specific case, together with associated requirements for nanosystems, devices, and sensors for controlling doping levels and doping profiles on the nanometric scale. Another series of examples of the flexibility provided by the marriage of organic functional monolayers and inorganic device components are represented by a new class of biosensors, where the organic layer functionality is exploited in a functioning device for sensing. Considerations for relying on oxide-terminated semiconductors rather than the pristine semiconductor material as a platform both for processing and sensing are discussed. Finally, we cover aspects related to the use of various theoretical and computational approaches to model organic-inorganic systems. The main objectives of the topics covered here are (i) to present the advances made in each respective domain and (ii) to provide a comprehensive view of the potential uses of organic monolayers and self-assembly processes in the rapidly evolving field of molecular-inorganic hybrid device platforms and processing methodologies. The directions highlighted here provide a perspective on a future, not yet fully realized, integrated approach where organic monolayers are combined with inorganic platforms in order to obtain versatile, robust, and flexible systems with enhanced capabilities.

Abstract P3-15-05: Early breast cancer in the elderly: characteristics, therapy, and long-term outcome

Objective: The number of older adults diagnosed with breast cancer is increasing. However, data on breast cancer characteristics, treatment, and survival in elderly women are sparse.

Methods: The database of a tertiary cancer center was searched for all women aged &gt;65 years who were diagnosed with early breast cancer in 2004-2007. Patients were divided into two age groups: 65-75 years and &gt;75 years. Data on tumor, treatment and outcome parameters were compared.

Results: The cohort included 390 patients. The older group underwent more mastectomies but less axillary surgery or adjuvant systemic therapy. Median overall survival (OS) was 9.5 years in the older group and not reached in the younger group; the 8 year disease-free survival rates were 85% and 88%, respectively (p=0.27). Both age and tumor subtype had an effect on OS and recurrence rates (p&lt;0.001 for OS; p=0.16 for recurrence). The worst outcome was noted in women aged &gt;75 years with triple-negative (TN) disease.

Conclusion: Treatment approach was different between both age groups, despite similar tumor characteristics. TN subtype presented as the most aggressive disease in both age groups. Physicians should be alert to these findings and select treatment on a case-by-case basis.

Citation Format: Gal O, Ishai Y, Sulkes A, Shochat T, Yerushalmi R. Early breast cancer in the elderly: characteristics, therapy, and long-term outcome [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-15-05.

Impact of baseline BMI and weight change in CCTG adjuvant breast cancer trials

Background

We hypothesized that increased baseline BMI and BMI change would negatively impact clinical outcomes with adjuvant breast cancer systemic therapy.

Methods

Data from chemotherapy trials MA.5 and MA.21; endocrine therapy MA.12, MA.14 and MA.27; and trastuzumab HERA/MA.24 were analyzed. The primary objective was to examine the effect of BMI change on breast cancer-free interval (BCFI) landmarked at 5 years; secondary objectives included BMI changes at 1 and 3 years; BMI changes on disease-specific survival (DSS) and overall survival (OS); and effects of baseline BMI. Stratified analyses included trial therapy and composite trial stratification factors.

Results

In pre-/peri-/early post-menopausal chemotherapy trials (N = 2793), baseline BMI did not impact any endpoint and increased BMI from baseline did not significantly affect BCFI (P = 0.85) after 5 years although it was associated with worse BCFI (P = 0.03) and DSS (P = 0.07) after 1 year. BMI increase by 3 and 5 years was associated with better DSS (P = 0.01; 0.01) and OS (P = 0.003; 0.05). In pre-menopausal endocrine therapy trial MA.12 (N = 672), patients with higher baseline BMI had worse BCFI (P = 0.02) after 1 year, worse DSS (P = 0.05; 0.004) after 1 and 5 years and worse OS (P = 0.01) after 5 years. Increased BMI did not impact BCFI (P = 0.90) after 5 years, although it was associated with worse BCFI (P = 0.01) after 1 year. In post-menopausal endocrine therapy trials MA.14 and MA.27 (N = 8236), baseline BMI did not significantly impact outcome for any endpoint. BMI change did not impact BCFI or DSS after 1 or 3 years, although a mean increased BMI of 0.3 was associated with better OS (P = 0.02) after 1 year. With the administration of trastuzumab (N = 1395) baseline BMI and BMI change did not significantly impact outcomes.

Conclusions

Higher baseline BMI and BMI increases negatively affected outcomes only in pre-/peri-/early post-menopausal trial patients. Otherwise, BMI increases similar to those expected in healthy women either did not impact outcome or were associated with better outcomes.

Clinical Trials numbers

CAN-NCIC-MA5; National Cancer Institute (NCI)-V90-0027; MA.12-NCT00002542; MA.14-NCT00002864; MA.21-NCT00014222; HERA, NCT00045032;CAN-NCIC-MA24; MA-27-NCT00066573.

1-D Metal Nanobead Arrays within Encapsulated Nanowires via a Red-Ox-Induced Dewetting: Mechanism Study by Atom-Probe Tomography

Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core-shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal-germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal-germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal-germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau-Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.

Criteria and considerations for preparing atom-probe tomography specimens of nanomaterials utilizing an encapsulation methodology

Atom-probe tomography (APT) is a powerful method for characterization of nanomaterials due to its atomic-ppm level detection limit and Angstrom spatial resolution. Sample preparation for nanomaterials is, however, challenging because of their small dimensions and complicated geometries. Nanowires, with their high geometrical aspect ratio and nanowire length, 10 to 100 times their typical diameters, are highly suitable specimens for APT analyses, which can be transferred to silicon microposts using a nanomanipulator for direct APT measurements. This method is, however, prone to poor alignment and a limited field-of-view (FOV). Most importantly, direct implementation of APT with high aspect ratio nanowires may yield a low success rate of ∼30%, due to the high electric fields (10-40 V nm^-1) associated with APT. While this is acceptable for samples analyzed solely by APT, a low sample yield makes it challenging to perform correlative experiments on the same nanowire specimen, utilizing other sophisticated characterization instruments. Herein, we introduce a general strategy for preparing high-yield APT specimens by encapsulating the nanowires utilizing a conformal atomic-layer deposition (ALD) coating followed by site-specific lift-out using a dual-beam focused-ion beam microscope. The ALD deposited coating forms strong chemical bonds with the Si nanowires yielding a high-quality and robust interface. The evaporation electric fields of the ALD coating and the nanowires are tuned by changing laser energy to obtain a uniform evaporation rate. The strong adhesion of the ALD-coating/nanowire interface and uniform evaporation rate produce a >90% specimen yield, with small concentration of reconstruction artifacts in 3-D. Simultaneously, the field-of-view is enhanced and the surface of the nanowire becomes visible, which makes the study of surface adsorption, segregation and oxidation possible. We utilized ALD-ZnO coated silicon nanowires as an example for investigating the criteria for choosing coating materials, laser pulse energy, laser direction, sample geometry, and substrate materials. The same criteria and considerations are applicable for preparing specimens of nanoparticles and 2-D material.

Direct Dopant Patterning by a Remote Monolayer Doping Enabled by a Monolayer Fragmentation Study

The development of new doping methods extending beyond the traditional and well-established techniques is desired to match the rapid advances made in semiconductor (SC)-processing methods and nanostructure synthesis in numerous emerging applications, including the doping of 3D architectures. To address this, monolayer doping (MLD) and monolayer contact doping methods have been introduced recently. The MLD methods enable separation of the doping process of nanostructures from the synthesis step; hence, it is termed ex situ doping. Here, we present a new ex situ MLD method termed remote MLD (R-MLD). The noncontact doping method is based on the thermal fragmentation of dopant-containing monolayers and evaporation processes taking place during annealing of the uncapped monolayer dopant source positioned in proximity, however, without making physical contact with the target SC surface. We present a two-step annealing procedure that allows the study of the dopant monolayer fragmentation and evaporation stages and quantification of the doping levels obtained during each step. We demonstrate the application of R-MLD for achieving a large-scale direct patterning of silicon substrates with sharp doping profiles. The direct dopant patterning is obtained without applying lithographic processing steps to the target substrate. The noncontact doping process, monolayer decomposition, and fragment evaporation were studied using thermogravimetric analysis coupled with mass spectrometry and sheet resistance measurements. The doped patterns were characterized using scanning electron microscopy, scanning capacitance microscopy, and time-of-flight secondary ion mass spectroscopy.

Abstract P2-07-11: The association between angiotensin receptor blockers usage and breast cancer characteristics

Background: Data regarding the impact of angiotensin receptor blockers (ARB) on breast cancer are inconsistent. We evaluate the association between ARB usage and breast cancer characteristics and outcomes.

Methods: All patients who were treated in our institute for estrogen receptor positive, human epidermal growth factor receptor 2 negative early breast cancer between 4/2005 and 3/2012 and whose tumors were sent for Oncotype-DX analysis were included. Medical records were retrospectively reviewed for clinical-pathological parameters, related comorbidities, treatment and outcomes. Data regarding ARB usage was retrieved. Usage of several pre-specified medications for hypertension including angiotensin converting enzyme inhibitors (ACEI), mineralocorticoid receptor antagonists (MRA), and β-blockers (BB) was also evaluated. Each medication group was compared to the rest of the study population.

Results:671 patients were included in the study cohort. Forty six (7%) were treated with ARB, 93 (14.2%) with ACEI, 14 (2.1%) with MRA, and 115 (17.5%) with BB. ARB usage was associated with different histological subtype distribution (P=0.009), higher incidence of macroscopic nodal involvement (P&lt;0.001) and more advanced stage at diagnosis (p&lt;0.001). These findings remained significant on multivariate analysis. Patients treated with ARB had worse 5-year breast cancer specific survival (94.7% vs. 98.8%, P=0.024) and worse 5-year overall survival (94.6% vs. 98.8%, p=0.015), but these differences were not demonstrated on multivariate analysis (p=0.251 and p=0.441. respectively).

Conclusions: Patients treated with ARB presented with more advanced breast cancer disease and some distinct histological features. Further research is required to elucidate the effect of ARB treatment on breast cancer.

Tumor burdenPopulation (no.)Tumor size, cm (SD)Macroscopic node posotive1Stage Mean, cm (SD)P, univariate analysis%P, univariate analysisI, %II, %P, univariate analysisAll (671)1.68 (0.8)-9-71.228.3-ARB (46)1.89 (0.81)0.05423.9&lt;0.0013763&lt;0.001ACEI (93)1.93 (0.93)0.0048.50.86363.835.10.355MRA (14)1.88 (0.67)0.32914.30.36357.142.90.907BB (115)1.77 (0.95)0.21613.20.08766.731.60.0911Macroscopic nodes: lymph node metastases&gt; 2 millimeter

Histological characteristicsPopulation (no.)Ki67 (%)Estrogen recepator stain intensityHistology subtype Mean, (SD)P, univariate analysisMean, (SD)P, univariate analysisIDC (%)ILC (%)P, univariate analysisAll (671)15.91 (13.58)-2.47 (0.57)-80.912.2-ARB (46)12.27 (7.19)0.0052.57 (0.59)0.24665.226.10.009ACEI (93)17.1 (14.24)0.4032.44 (0.55)0.51575.5160.358MRA (14)21.4 (11.2)0.1972.63 (0.42)0.30385.87.10.841BB (115)15.93 (12.93)0.992.51 (0.58)0.49675.713.90.186IDC- invasive ductal carcinoma, ILC- invasive lobular carcinoma

Citation Format: Goldvaser H, Rizel S, Hendler D, Neiman V, Shepshelovich D, Shochat T, Sulkes A, Brenner B, Yerushalmi R. The association between angiotensin receptor blockers usage and breast cancer characteristics [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-07-11.

Abstract OT2-01-13: A phase 3, open-label, randomized, 2-arm international study of the oral dual PARP inhibitor talazoparib in germline BRCA mutation subjects with locally advanced and/or metastatic breast cancer (EMBRACA)

Background: Cancer cells with deleterious mutations in breast cancer susceptibility genes 1 and 2 (BRCA1/2) are deficient in the DNA double-strand break repair mechanism, rendering them highly dependent on the single-strand break repair pathway, regulated by poly(ADP-ribose) polymerase (PARP). Inhibition of PARP results in synthetic lethality in cells with a BRCA1/2 mutation because of accumulation of irreparable DNA damage; PARP inhibitors have the potential to be selectively toxic for BRCA-mutated cells. In addition to catalytic inhibition, it has been shown that some PARP inhibitors induce PARP trapping at sites of DNA damage. The capacity to trap PARP-DNA complexes varies widely across different PARP inhibitors and is not correlated with PARP catalytic inhibition. Preclinical models have shown trapping PARP on DNA is more potent at inducing cancer cell death than enzymatic inhibition of PARP alone. Talazoparib is a dual-mechanism PARP inhibitor that both inhibits the PARP enzyme and effectively traps PARP on DNA, preventing DNA damage repair and resulting in cell death in BRCA1/2-mutated cells. In preclinical studies, talazoparib at nanomolar concentrations showed the highest efficiency at trapping PARP-DNA complexes relative to other PARP inhibitors. In a previous phase 1/2 clinical study, talazoparib as monotherapy (1 mg once daily) resulted in a 50% response rate and an 86% clinical benefit rate at 24 weeks in 14 patients with a germline BRCA1/2 mutation and advanced breast cancer (aBC).

Methods: This open-label, randomized, 2-arm, international phase 3 trial (EMBRACA)

compares the efficacy and safety of talazoparib with protocol-specific physician's choice (capecitabine, eribulin, gemcitabine or vinorelbine) in patients with aBC. The primary objective is progression-free survival by central imaging. Secondary objectives are objective response rate, overall survival, safety and pharmacokinetics of talazoparib. Exploratory objectives include health-related quality of life measurements and biomarker research in blood and tumor samples that may permit characterization of mechanisms involved in tumor sensitivity and resistance to talazoparib. Key patient eligibility criteria include aged ≥18 years with histologically/cytologically confirmed breast cancer; locally advanced and/or metastatic disease appropriate for systemic single-agent cytotoxic chemotherapy; deleterious or pathogenic germline BRCA1/2 mutations by central laboratory; ≤3 prior cytotoxic chemotherapy regimens for advanced disease (prior platinum is allowed provided patients did not relapse within 6 months in the adjuvant setting or did not progress on platinum therapy); prior treatment with a taxane and/or anthracycline unless medically contraindicated; and ECOG performance status ≤2. Patients (N=429) will be randomized 2:1 to receive either talazoparib capsules (1 mg/day, 21-day cycles) or physician's choice treatment. This trial is currently enrolling patients from the USA, Europe, Israel, Ukraine, Russia, Korea, Australia, Taiwan and Brazil (NCT01945775).

This study is funded by Medivation, Inc.

Citation Format: Litton J, Ettl J, Hurvitz SA, Mina LA, Rugo HS, Lee K-H, Yerushalmi R, Woodward N, Goncalves A, Moreno F, Roche H, Im Y-H, Martin M, Bhattacharya S, Peterson A, Hannah A, Eiermann W, Blum J. A phase 3, open-label, randomized, 2-arm international study of the oral dual PARP inhibitor talazoparib in germline BRCA mutation subjects with locally advanced and/or metastatic breast cancer (EMBRACA) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-13.

Abstract P5-08-25: The association between smoking and breast cancer characteristics and outcome

Background: Smoking is associated with an increased incidence of hormone receptor positive breast cancer. Data regarding worse breast cancer outcome in smokers are accumulating. Current literature regarding the impact of smoking on breast cancer characteristics is limited. The aim of this study was to evaluate the impact of smoking on the characteristics and outcome of estrogen receptor positive, human epidermal growth factor receptor 2 (HER2) negative early breast cancer.

Methods: This was a retrospective single center study. All patients diagnosed from 4/2005 through 3/2012 and treated in our institute for early, estrogen receptor positive, HER2 negative breast cancer, whose tumors were sent for Oncotype DX analysis were included. Medical records were reviewed for demographics, clinico-pathological parameters, treatment and outcome. Patients were grouped and compared according to smoking history (present or past smokers vs. never smokers) and status (current vs. former and never smokers). Heavy smokers (pack years ≥30) were analyzed separately.

Results: A total of 671 patients were included. 28.7% had a history of smoking, 17% were current smokers and 11.5% were heavy smokers. Smoking had no impact on tumor size, nodal involvement and Oncotype DX recurrence score. Angiolymphatic and perineural invasion rates were higher in current smokers than in the rest of the cohort (11% vs. 5.1%, p=0.023, 9% vs. 3.45%, p=0.013, respectively). Smoking had no other impact regarding histological characteristics. Five-year disease free survival and overall survival rates were 95.7% and 98.5%, respectively. Smoking had no impact on outcome.

Conclusions: In patients with estrogen receptor positive, HER2 negative, early breast cancer, smoking had no clinically significant influence on tumor characteristics and outcome. As the study was limited to a specific subgroup of the breast cancer population in this heterogeneous disease and since smoking is a modifiable risk factor for the disease, further research is required to clarify the possible impact of smoking on breast cancer.

Breast cancer characteristics according to history of smoking, smoking status and pack yearsPopulation (no.)Mean tumor size, cm (SD)Macroscopic N + (%)Oncotype Dx RS, mean (SD)Histology, IDC (%)Angiolymphatic invasion (%)Perniural invasion (%)Ki67 (%), mean (SD)Hx smoking (178)1.66 (0.9)10.718.9 (9.4)817.75.915.8 (13.5)No Hx of smoking (443)1.7 (0.8)8.419.33 (10.8)805.43.816 (14.1)Active smokers (104)1.76 (1)9.619.7 (9)8211916.5 (14.6)Never/former smokers (513)1.68 (0.8)919.1 (10.5)805.13.515.8 (13.7)PY 0-29 (523)1.69 (0.8)9.419.2 (10.7)806416.2 (14.2)PY≥30 (67)1.67 (1)918.3 (8.8)859913.8 (12.1)

Citation Format: Goldvaser H, Gal O, Rizel S, Hendler D, Neiman V, Shochat T, Sulkes A, Brenner B, Yerushalmi R. The association between smoking and breast cancer characteristics and outcome [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-25.

Self-formed nanogap junctions for electronic detection and characterization of molecules and quantum dots

Fabrication of self-forming nanojunction devices is demonstrated using positioning of nanofloret-like building blocks that bridge the gap between two large micron scale electrodes.

Malignancy associated SIADH: Characterization and clinical implications

PURPOSE

To determine the distribution of etiologies for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in hospitalized patients with active malignancies and to characterize them according to the different etiologies.

METHODS

A single center retrospective study including all patients with active malignancies diagnosed with SIADH in a large community hospital and tertiary center between 1 January 2007 and 1 January 2013. Two physicians reviewed every patient's medical file for predetermined relevant clinical data.

RESULTS

The study cohort included 204 patients. 74.4% of those with solid tumors had metastatic disease. Most patients (149, 73%) had malignancy associated SIADH, while 55 (27%) had SIADH due to other etiologies. All of the major malignancy types were implicated in SIADH. Patients with breast cancer without lung or brain involvement were significantly less likely to be diagnosed with malignancy associated SIADH compared with other malignancies [Odds ratio (OR) 0.031, 95% CI 0.003-0.25, p < 0.001]. Patients with malignancy associated SIADH had lower serum sodium concentrations on short-term follow-up (p = 0.024) and significantly shorter median survival (58 vs. 910 days, p < 0.001). Short-term hyponatremia correction was associated with better survival.

CONCLUSIONS

SIADH is associated with most malignancy types. Physicians caring for patients with breast cancer without lung or brain involvement diagnosed with SIADH without an obvious etiology should consider obtaining lung and brain imaging to rule out undiagnosed metastatic spread. Patients with malignancy associated SIADH have considerably worse outcomes compared to cancer patient with SIADH due to other etiologies. Short-term sodium concentration can be used as a prognostic marker for these patients.

Dopant Diffusion and Activation in Silicon Nanowires Fabricated by ex Situ Doping: A Correlative Study via Atom-Probe Tomography and Scanning Tunneling Spectroscopy

Dopants play a critical role in modulating the electric properties of semiconducting materials, ranging from bulk to nanoscale semiconductors, nanowires, and quantum dots. The application of traditional doping methods developed for bulk materials involves additional considerations for nanoscale semiconductors because of the influence of surfaces and stochastic fluctuations, which may become significant at the nanometer-scale level. Monolayer doping is an ex situ doping method that permits the post growth doping of nanowires. Herein, using atom-probe tomography (APT) with subnanometer spatial resolution and atomic-ppm detection limit, we study the distributions of boron and phosphorus in ex situ doped silicon nanowires with accurate control. A highly phosphorus doped outer region and a uniformly boron doped interior are observed, which are not predicted by criteria based on bulk silicon. These phenomena are explained by fast interfacial diffusion of phosphorus and enhanced bulk diffusion of boron, respectively. The APT results are compared with scanning tunneling spectroscopy data, which yields information concerning the electrically active dopants. Overall, comparing the information obtained by the two methods permits us to evaluate the diffusivities of each different dopant type at the nanowire oxide, interface, and core regions. The combined data sets permit us to evaluate the electrical activation and compensation of the dopants in different regions of the nanowires and understand the details that lead to the sharp p-i-n junctions formed across the nanowire for the ex situ doping process.

Semiconductor-Metal Nanofloret Hybrid Structures by Self-Processing Synthesis

We present a synthetic strategy that takes advantage of the inherent asymmetry exhibited by semiconductor nanowires prepared by Au-catalyzed chemical vapor deposition (CVD). The metal-semiconductor junction is used for activating etch, deposition, and modification steps localized to the tip area using a wet-chemistry approach. The hybrid nanostructures obtained for the coinage metals Cu, Ag, and Au resemble the morphology of grass flowers, termed here Nanofloret hybrid nanostructures consisting of a high aspect ratio SiGe nanowire (NW) with a metallic nanoshell cap. The synthetic method is used to prepare hybrid nanostructures in one step by triggering a programmable cascade of events that is autonomously executed, termed self-processing synthesis. The synthesis progression was monitored by ex situ transmission electron microscopy (TEM), in situ scanning transmission electron microscopy (STEM) and inductively coupled plasma mass spectrometry (ICP-MS) analyses to study the mechanistic reaction details of the various processes taking place during the synthesis. Our results indicate that the synthesis involves distinct processing steps including localized oxide etch, metal deposition, and process termination. Control over the deposition and etching processes is demonstrated by several parameters: (i) etchant concentration (water), (ii) SiGe alloy composition, (iii) reducing agent, (iv) metal redox potential, and (v) addition of surfactants for controlling the deposited metal grain size. The NF structures exhibit broad plasmonic absorption that is utilized for demonstrating surface-enhanced Raman scattering (SERS) of thiophenol monolayer. The new type of nanostructures feature a metallic nanoshell directly coupled to the crystalline semiconductor NW showing broad plasmonic absorption.

Parallel p-n junctions across nanowires by one-step ex situ doping

The bottom-up synthesis of nanoscale building blocks is a versatile approach for the formation of a vast array of materials with controlled structures and compositions. This approach is one of the main driving forces for the immense progress in materials science and nanotechnology witnessed over the past few decades. Despite the overwhelming advances in the bottom-up synthesis of nanoscale building blocks and the fine control of accessible compositions and structures, certain aspects are still lacking. In particular, the transformation of symmetric nanostructures to asymmetric nanostructures by highly controlled processes while preserving the modified structural orientation still poses a significant challenge. We present a one-step ex situ doping process for the transformation of undoped silicon nanowires (i-Si NWs) to p-type/n-type (p-n) parallel p-n junction configuration across NWs. The vertical p-n junctions were measured by scanning tunneling microscopy (STM) in concert with scanning tunneling spectroscopy (STS), termed STM/S, to obtain the spatial electronic properties of the junction formed across the NWs. Additionally, the parallel p-n junction configuration was characterized by off-axis electron holography in a transmission electron microscope to provide an independent verification of junction formation. The doping process was simulated to elucidate the doping mechanisms involved in the one-step p-i-n junction formation.

Tailor-made oxide architectures attained by molecularly permeable metal-oxide organic hybrid thin films

Tailor-made metal oxide (MO) thin films with controlled compositions, electronic structures, and architectures are obtained via molecular layer deposition (MLD) and solution treatment.

Monolayer contact doping of silicon surfaces and nanowires using organophosphorus compounds

Monolayer Contact Doping (MLCD) is a simple method for doping of surfaces and nanostructures(1). MLCD results in the formation of highly controlled, ultra shallow and sharp doping profiles at the nanometer scale. In MLCD process the dopant source is a monolayer containing dopant atoms. In this article a detailed procedure for surface doping of silicon substrate as well as silicon nanowires is demonstrated. Phosphorus dopant source was formed using tetraethyl methylenediphosphonate monolayer on a silicon substrate. This monolayer containing substrate was brought to contact with a pristine intrinsic silicon target substrate and annealed while in contact. Sheet resistance of the target substrate was measured using 4 point probe. Intrinsic silicon nanowires were synthesized by chemical vapor deposition (CVD) process using a vapor-liquid-solid (VLS) mechanism; gold nanoparticles were used as catalyst for nanowire growth. The nanowires were suspended in ethanol by mild sonication. This suspension was used to dropcast the nanowires on silicon substrate with a silicon nitride dielectric top layer. These nanowires were doped with phosphorus in similar manner as used for the intrinsic silicon wafer. Standard photolithography process was used to fabricate metal electrodes for the formation of nanowire based field effect transistor (NW-FET). The electrical properties of a representative nanowire device were measured by a semiconductor device analyzer and a probe station.

Do alternative methods of measuring tumor size, including consideration of multicentric/multifocal disease, enhance prognostic information beyond TNM staging in women with early stage breast cancer: an analysis of the NCIC CTG MA.5 and MA.12 clinical trials

The AJCC staging criteria consider tumor size to be the largest dimension of largest tumor. Some case series suggest using summation of all tumor dimensions in patients with multicentric/multifocal (MC/MF) disease. We used data from NCIC CTG MA.5 and MA.12 clinical trials to examine alternative methods of assessing tumor size on breast-cancer-free-interval (BCFI). The 710 MA.5 pre-/peri-menopausal node positive and 672 MA.12 pre-menopausal node-negative/-positive patients have 10-year median follow-up. All patients received adjuvant chemotherapy. Tumors were centrally reviewed for grade, hormone receptor, and HER2 status. Continuous pathologic tumor size was: (1) largest dimension of largest tumor (cm); (2) tumor area (cm(2)); (3) volume of tumor (cm(3)); (4) with MC/MF disease, summation of (1)-(3) for up to 3 foci. We examined univariate and multivariate effects of tumor size on BCFI utilizing (un)stratified Cox regression and the Wald test statistic. In univariate analysis, larger tumor dimension was significantly associated with worse BFCI in node positive patients: p < 0.0001 for MA.5; p = 0.01 for MA.12. In MA.5 multivariate analysis, larger summation of largest tumor dimensions was associated with worse BCFI (p = 0.0003), while larger single dimension was associated with worse BCFI (p = 0.02) for MA.12. Presence of MC/MF and other tumor size measurements were not associated (p > 0.05) with BFCI. While physicians could consider the largest diameter of the largest focus of disease or the sum of the largest diameters of all foci in their T-stage determination, it appears that the current method of T-staging offers equivalent determinations of prognosis.

Breast cancer and leptomeningeal disease (LMD): hormone receptor status influences time to development of LMD and survival from LMD diagnosis

Leptomeningeal disease (LMD) occurs in 5 % of breast cancer patients. The aim of this study was to identify risk factors related to survival and time to development of LMD in breast cancer patients. A retrospective analysis of breast cancer patients with LMD, evaluated in MDACC between 1995 and 2011. 103 patients with diagnosis of breast cancer and LMD were identified (one male). The median age at LMD diagnosis was 49.2 years. 78.2 % had invasive ductal carcinoma. Hormone receptors (HRs) were positive in 55.3 % of patients, 47.4 % were human epidermal growth factor receptor 2-positive and 22.8 % were triple negative. 52 % of the patients were treated with WBRT, 19 % with spinal radiation, 36 % with systemic chemotherapy and 55 % with intrathecal chemotherapy. Estimated median overall survival from time of breast cancer diagnosis was 3.66 years. Median survival from time of LMD diagnosis was 4.2 months. Time from breast cancer diagnosis to LMD was 2.48 years. In multivariate analysis, HR status and stage at diagnosis were significantly associated with time to LMD diagnosis (p < 0.05). In triple negative patients, time to LMD was shorter. In patients who were HR positive, time to LMD was longer. Survival from LMD diagnosis was significantly associated with both treatment, as well as positive HR status (multivariate analysis p < 0.05). In conclusion LMD has dismal prognosis in breast cancer patients. HR status contributes to time to LMD diagnosis and survival from LMD diagnosis. The impact of treatment aimed at LMD cannot be ascertained in our retrospective study due to the inherent bias associated with the decision to treat.

Contact doping of silicon wafers and nanostructures with phosphine oxide monolayers

Contact doping method for the controlled surface doping of silicon wafers and nanometer scale structures is presented. The method, monolayer contact doping (MLCD), utilizes the formation of a dopant-containing monolayer on a donor substrate that is brought to contact and annealed with the interface or structure intended for doping. A unique feature of the MLCD method is that the monolayer used for doping is formed on a separate substrate (termed donor substrate), which is distinct from the interface intended for doping (termed acceptor substrate). The doping process is controlled by anneal conditions, details of the interface, and molecular precursor used for the formation of the dopant-containing monolayer. The MLCD process does not involve formation and removal of SiO(2) capping layer, allowing utilization of surface chemistry details for tuning and simplifying the doping process. Surface contact doping of intrinsic Si wafers (i-Si) and intrinsic silicon nanowires (i-SiNWs) is demonstrated and characterized. Nanowire devices were formed using the i-SiNW channel and contact doped using the MLCD process, yielding highly doped SiNWs. Kelvin probe force microscopy (KPFM) was used to measure the longitudinal dopant distribution of the SiNWs and demonstrated highly uniform distribution in comparison with in situ doped wires. The MLCD process was studied for i-Si substrates with native oxide and H-terminated surface for three types of phosphorus-containing molecules. Sheet resistance measurements reveal the dependency of the doping process on the details of the surface chemistry used and relation to the different chemical environments of the P═O group. Characterization of the thermal decomposition of several monolayer types formed on SiO(2) nanoparticles (NPs) using TGA and XPS provides insight regarding the role of phosphorus surface chemistry at the SiO(2) interface in the overall MLCD process. The new MLCD process presented here for controlled surface doping provides a simple yet highly versatile means for achieving postgrowth doping of nanometer scale structures and interfaces.

Transformation of organic-inorganic hybrid films obtained by molecular layer deposition to photocatalytic layers with enhanced activity

We present the transformation of organic-inorganic hybrid titanicone films formed by TiCl(4) as metal precursor and ethylene glycol (EG) using solvent-free MLD to highly active photocatalytic films. The photocatalytic activities of the films were investigated using hydroxyl-functionalized porphyrin as a spectroscopic marker. TEM imaging and electron diffraction, XPS, UV-vis spectroscopy, and spectroscsopic ellipsometry were employed for structural and composition analyses of the films. The photocatalytic activity of Ti-EG films was investigated for different anneal temperatures and compared to TiO(2) films prepared by ALD using TiCl(4) as metal precursor and H(2)O (TiO(2) films). Overall, our results indicate that the photocatalytic activity of the thermally annealed Ti-EG film is about 5-fold increased compared to that of the TiO(2) film prepared by ALD for optimal process conditions. The combined results indicate that the structural and photocatalytic properties can be assigned to three states: (I) amorphous state, intermediate dye loading, low photocatalytic activity, (II) intermediate film state with both crystalline and amorphous regions, high dye loading, high catalytic activity, and (III) highly crystalline film with low dye loading and low photocatalytic activity. The formation of photocatalytic nanotubes (NTs) is demonstrated using sacrificial Ge nanowires (NWs) scaffolds to yield Ti-EG NT structures with controllable wall thickness structures and enhanced dye loading capacity. Our results demonstrate the feasibility and high potential of MLD to form metal oxides with high photocatalytic activity.

P5-14-01: Differences in Efficacy by Assessment Method: NCIC CTG Adjuvant Breast Cancer Trials MA.5, MA.12, MA.14, MA.21, MA.27 Meta-Analysis

Background: Based on recent breast cancer literature, we hypothesized that there could be substantive differences in apparent efficacy estimates using a log-normal (LN) survival model rather than with standard Kaplan-Meier (K-M) or Cox model methods. While both Cox and LN survival analyses offer greater specification by individual patient characteristics, the LN model may more robustly estimate survival under model misspecification. Methods: We recently pooled data for 5 NCIC CTG primary breast cancer trials: MA.5, MA.12, MA.14, MA.21, and MA.27. The total patient count for patients who received at least 1 dose of trial therapy is 11,253. Compilation included definition of STEEP endpoints (C Hudis, JCO, 2008) and standardized factor categorizations. The primary endpoint is Breast Cancer Free Interval (BCFI) defined as the time from randomization until recurrence: first local invasive or DCIS; regional, or distant; contralateral invasive or DCIS; or death from breast cancer. We found substantive evidence of non-proportionality for 7 factors compiled for the meta-analyses. In this work, we fit multivariate Cox and LN models with these 7 factors, lymph node status and pathologic T status. We then compare BCFI efficacy estimates for patient and tumour characteristics at 1-, 3-, and 5-years obtained with K-M, Cox, and LN models. Results: There was evidence that the Cox assumption of proportional hazards was violated for 7 factors: age, menopausal status, hormone receptor status, anthracycline use, chemotherapy use, race, and ECOG performance status. Differences between models were intrinsically affected by timing and extent of non-proportionality; there was no consistent pattern. In particular, investigations to date indicate efficacy estimates with absolute differences between K-M, Cox and LN estimates which varied by time of assessment: at 1-year 0.0 to 6.7%, at 3-years 0.4 to 18.6%, and at 5-years 0.2 to 17.0%. BCFI estimates with the K-M were inconsistently closer to those with the LN or Cox model: for K-M to Cox at 1-year 0.4 to 5.2%, at 3-years 0.4 to 15%, at 5-years 0.4 to 14.3%; for K-M to LN at 1-year 0.0 to 6.7%, at 3-years 0.5 to 18.6%, at 5-years 0.2 to 17.0%; for Cox to LN at 1-year 0.8 to 1.8%, at 3-years 1.9 to 6.0%, at 5-years 0.6 to 5.7%. K-M and Cox models have step-wise adjustments at events for K-M and Cox, rather than smooth modeling with the LN. Discussion: Even with reasonably large population subgroups, there were substantive differences in apparent survival (0.0 to 18.6%) between K-M, Cox and LN model types. The magnitude of differences in survival estimates was large enough to be clinically relevant and warrant further consideration as we evaluate new therapies and prognostic/predictive factors. We will be statistically investigating framework robustness under differing levels of model misspecification.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-14-01.

P2-12-27: Simply Adding Together the Diameters of Tumor Foci in Patients with Multicentric or Multifocal Disease Does Not Add Any Additional Prognostic Information: An Analysis from NCIC CTG MA.12 Randomized Placebo-Controlled Trial of Tamoxifen after Adjuvant Chemotherapy in Pre-Menopausal Women with Early Breast Cancer

Background: A common clinical conundrum in breast cancer management is whether pathologic T stage in women with multicentric or multifocal disease should be taken as the diameter of the largest focus or as the sum of all foci in the breast. Most staging systems, such as the American Joint Committee on Cancer (AJCC), simply use the largest tumor focus for staging. We examine here the impact of alternate methods of estimating tumour size including measures of total tumor size, volume and surface area.

Materials & Methods: NCIC CTG MA.12 is a randomized placebo-controlled trial of tamoxifen after adjuvant chemotherapy for pre-menopausal women with early breast cancer. Median follow up is 9.7 years. Pathologically reported patient tumor dimensions for up to 3 foci were utilized to examine the effects of tumor size on Breast-Cancer-Free-Interval (BCFI), defined as the time from randomization until recurrence (defined as first local, regional, distant, or contralateral invasive tumor or DCIS). Tumor size was estimated as 1) pathologic T stage as per AJCC criteria; 2) largest dimension of largest tumor focus (cm); 3) sum of largest dimension(s) of tumor foci (cm); 4) sum of surface area(s) of tumor foci (cm2), and 5) sum of volume of tumor foci (cm3). Step-wise forward unstratified Cox regression was used to assess the different effects of tumor size. Results: This study accrued 672 patients, 43% with T1 tumors, 51% with T2 tumors, and 6% with T3/T4 tumors; 25% were node negative and 56% had 1–3 positive lymph nodes. 75% were locally determined to have hormone receptor positive tumors. A higher number of involved lymph nodes was associated with significantly shorter BCFI (p&lt;0.0001). None of pathologic T stage (p=0.14), largest dimension of largest tumor size (p=0.14), sum of largest dimensions of tumor foci (p=0.24), sum of surface area (p=0.38), and sum of volume of foci (p=0.51) were significantly associated with BCFI. Likewise, lymphovascular invasion (p=0.08), grade (p=0.14), nor administration of anthracycline therapy (p=0.08) were associated with BCFI.

Discussion: In the MA.12 population of pre-menopausal women randomized to either tamoxifen or placebo, the sole factor significantly associated with BCFI was nodal status. No measure of tumor size in unifocal or multicentric/multifocal tumors impacted BCFI. The findings of this mature data set suggest that simply adding together the diameters of tumors in patients with multicentric or multifocal disease did not add any additional prognostic information.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-27.