Comprehensive evaluations of diurnal NO2 measurements during DISCOVER-AQ 2011: effects of resolution-dependent representation of NO x emissions

Nitrogen oxides (NO _x =NO+NO₂) play a crucial role in the formation of ozone and secondary inorganic and organic aerosols, thus affecting human health, global radiation budget, and climate. The diurnal and spatial variations in NO₂ are functions of emissions, advection, deposition, vertical mixing, and chemistry. Their observations, therefore, provide useful constraints in our understanding of these factors. We employ a Regional chEmical and trAnsport model (REAM) to analyze the observed temporal (diurnal cycles) and spatial distributions of NO₂ concentrations and tropospheric vertical column densities (TVCDs) using aircraft in situ measurements and surface EPA Air Quality System (AQS) observations as well as the measurements of TVCDs by satellite instruments (OMI: the Ozone Monitoring Instrument; GOME-2A: Global Ozone Monitoring Experiment - 2A), ground-based Pandora, and the Airborne Compact Atmospheric Mapper (ACAM) instrument in July 2011 during the DISCOVER-AQ campaign over the Baltimore-Washington region. The model simulations at 36 and 4 km resolutions are in reasonably good agreement with the regional mean temporospatial NO₂ observations in the daytime. However, we find significant overestimations (underestimations) of model-simulated NO₂ (O₃) surface concentrations during night-time, which can be mitigated by enhancing nocturnal vertical mixing in the model. Another discrepancy is that Pandora-measured NO₂ TVCDs show much less variation in the late afternoon than simulated in the model. The higher-resolution 4 km simulations tend to show larger biases compared to the observations due largely to the larger spatial variations in NO _x emissions in the model when the model spatial resolution is increased from 36 to 4 km. OMI, GOME-2A, and the high-resolution aircraft ACAM observations show a more dispersed distribution of NO₂ vertical column densities (VCDs) and lower VCDs in urban regions than corresponding 36 and 4 km model simulations, likely reflecting the spatial distribution bias of NO _x emissions in the National Emissions Inventory (NEI) 2011.

Bridging the age gap in breast cancer: cluster randomized trial of two decision support interventions for older women with operable breast cancer on quality of life, survival, decision quality, and treatment choices

BACKGROUND

Rates of surgery and adjuvant therapy for breast cancer vary widely between breast units. This may contribute to differences in survival. This cluster RCT evaluated the impact of decision support interventions (DESIs) for older women with breast cancer, to ascertain whether DESIs influenced quality of life, survival, decision quality, and treatment choice.

METHODS

A multicentre cluster RCT compared the use of two DESIs against usual care in treatment decision-making in older women (aged at least ≥70 years) with breast cancer. Each DESI comprised an online algorithm, booklet, and brief decision aid to inform choices between surgery plus adjuvant endocrine therapy versus primary endocrine therapy, and adjuvant chemotherapy versus no chemotherapy. The primary outcome was quality of life. Secondary outcomes included decision quality measures, survival, and treatment choice.

RESULTS

A total of 46 breast units were randomized (21 intervention, 25 usual care), recruiting 1339 women (670 intervention, 669 usual care). There was no significant difference in global quality of life at 6 months after the baseline assessment on intention-to-treat analysis (difference -0.20, 95 per cent confidence interval (C.I.) -2.69 to 2.29; P = 0.900). In women offered a choice of primary endocrine therapy versus surgery plus endocrine therapy, knowledge about treatments was greater in the intervention arm (94 versus 74 per cent; P = 0.003). Treatment choice was altered, with a primary endocrine therapy rate among women with oestrogen receptor-positive disease of 21.0 per cent in the intervention versus 15.4 per cent in usual-care sites (difference 5.5 (95 per cent C.I. 1.1 to 10.0) per cent; P = 0.029). The chemotherapy rate was 10.3 per cent at intervention versus 14.8 per cent at usual-care sites (difference -4.5 (C.I. -8.0 to 0) per cent; P = 0.013). Survival was similar in both arms.

CONCLUSION

The use of DESIs in older women increases knowledge of breast cancer treatment options, facilitates shared decision-making, and alters treatment selection. Trial registration numbers: EudraCT 2015-004220-61 (https://eudract.ema.europa.eu/), ISRCTN46099296 (http://www.controlled-trials.com).

COVID-19 Crisis Reduces Free Tropospheric Ozone Across the Northern Hemisphere

Throughout spring and summer 2020, ozone stations in the northern extratropics recorded unusually low ozone in the free troposphere. From April to August, and from 1 to 8 kilometers altitude, ozone was on average 7% (≈4 nmol/mol) below the 2000-2020 climatological mean. Such low ozone, over several months, and at so many stations, has not been observed in any previous year since at least 2000. Atmospheric composition analyses from the Copernicus Atmosphere Monitoring Service and simulations from the NASA GMI model indicate that the large 2020 springtime ozone depletion in the Arctic stratosphere contributed less than one-quarter of the observed tropospheric anomaly. The observed anomaly is consistent with recent chemistry-climate model simulations, which assume emissions reductions similar to those caused by the COVID-19 crisis. COVID-19 related emissions reductions appear to be the major cause for the observed reduced free tropospheric ozone in 2020.

Comparison of Near-surface NO2 Pollution with Pandora Total Column NO2 during the Korea-United States Ocean Color (KORUS OC) Campaign

Near-surface air quality (AQ) observations over coastal waters are scarce, a situation that limits our capacity to monitor pollution events at land-water interfaces. Satellite measurements of total column (TC) nitrogen dioxide (NO₂) observations are a useful proxy for combustion sources but the once daily snapshots available from most sensors are insufficient for tracking the diurnal evolution and transport of pollution. Ground-based remote sensors like the Pandora Spectrometer Instrument (PSI) that have been developed to verify space-based total column NO₂ and other trace gases are being tested for routine use as certified AQ monitors. The KORUS-OC (Korea-United States Ocean Color) cruise aboard the R/V Onnuri in May-June 2016 represented an opportunity to study AQ near the South Korean coast, a region affected by both local/regional and long-distance pollution sources. Using PSI data in direct-sun mode and in situ sensors for shipboard ozone, CO and NO₂, we explore, for the first time, relationships between TC NO₂ and surface AQ in this coastal region. Three case studies illustrate the value of the PSI as well as complexities in the surface-column NO₂ relationship caused by varying meteorological conditions. Case Study 1 (25-26 May 2016) exhibited a high correlation of surface NO₂ to TC NO₂ measured by both PSI and Aura's Ozone Monitoring Instrument (OMI) but two other cases displayed poor relationships between in situ and TC NO₂ due to decoupling of pollution layers from the surface. With suitable interpretation the PSI TC NO₂ measurement demonstrates good potential for working with upcoming geostationary satellites to advance diurnal tracking of pollution.

Abstract PD8-05: POSNOC - Positive sentinel node: Adjuvant therapy alone versus adjuvant therapy plus clearance or axillary radiotherapy

Background: Role of additional axillary treatment (AxT) (axillary lymph node dissection (ALND) or axillary radiotherapy (ART)) in women with ≤2 macrometastases and undergoing systemic therapy remains unclear. Z11 included both micro and macrometastases (around 40% micrometastases) and showed that ALND may be omitted in women with ≤2 positive nodes undergoing breast conserving surgery (BCS) and receiving whole breast RT. Paradoxically, NCIC MA20, demonstrated improved DFS following the addition of regional RT. 51.8% (949/1832) had 1 or 2 positive nodes. 98.9% (1812/1832) had T1/T2 tumours. A post-Z11 survey shows that most US radiation oncologists treat the undissected axilla in women with macrometastases with ART rather than omitting AxT. Therefore, a confirmatory study is needed to clarify the role of additional AxT in women with ≤2 macrometastases undergoing BCS and other subgroups that were not included in Z11 e.g. mastectomy, microscopic extranodal invasion and sentinel node biopsy (SNB) before neoadjuvant chemotherapy.

Methods: Primary objective is to assess whether for women with ≤2 macrometastases at SNB, systemic therapy alone is non-inferior to systemic therapy plus AxT in terms of axillary recurrence at 5 years. Secondary objectives are arm morbidity assessed by LBCQ and QuickDASH questionnaires; QoL assessed by FACT-B+4 questionnaire; anxiety assessed by STAI; loco-regional recurrence; distant metastasis; time to axillary recurrence; axillary recurrence-free survival; DFS; OS; contralateral breast cancer; non-breast malignancy; and economic evaluation. Eligibility criteria include: ≥18 y, uni or multifocal invasive cancer, T1/T2, 1 or 2 macrometastases, with or without extranodal invasion. Target sample size is 1900 with a projected drop-out and non-compliance with treatment allocation rate of 10%. Primary analysis will be per protocol. The following pre-specified subgroup analyses shall be performed: number of macrometastases (1, 2), age (<50, ≥50), breast surgery (mastectomy, BCS), ER (positive, negative), tumour grade (1 or 2, 3), SN assessment technique (OSNA, non-OSNA), extranodal invasion (present, absent). POSNOC opened to recruitment in July 2014. To date 1100 women have been recruited at 82 sites in the UK and 18 sites in Australia and New Zealand. Clinicaltrials.gov NCT02401685.

Citation Format: Goyal A, Mann B, Thompson AM. POSNOC - Positive sentinel node: Adjuvant therapy alone versus adjuvant therapy plus clearance or axillary radiotherapy [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 PD8-05.

Abstract P1-05-05: eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient breast cancer

The AURKA gene, encoding Aurora kinase-A (Aurora-A), is frequently amplified and overexpressed across multiple cancer types correlating with poor prognosis. Although the AURKA gene is frequently amplified in human cancers, underlying mechanism(s) for Aurora-A protein stability through different phases of cell cycle are not well elucidated. Inhibiting the kinase activity and promoting protein degradation are two well-validated conceptual strategies for targeting protein kinases in cancers. Here, we demonstrate that Eukaryotic Elongation Factor 1 Alpha 2 (eEF1A2) facilitates PTEN-GSK3β mediated Aurora-A protein degradation through the SCF complex (SKP1-Cul1-FBXW7) during the S/G2 phase of proliferating cells. In contrast, this mechanism is inactivated in cancer cells accompanying PTEN-GSK3β pathway deficiency. Mechanistically, eEF1A2 interacts with Aurora-A, GSK3β, FBXW7 and Cul1-E3 ligase, as the SCF complex, to facilitate Aurora-A polyubiquitination for 26S proteasomal degradation. eEF1A2 promotes PTEN phosphorylation at T366 and stability, inactivates AKT and activates GSK3β which in turn phosphorylates Aurora-A at S283, S284 and S342. The phosphorylation of Aurora-A at S342 is detected during S/G2 phase of cell mitosis in parallel with eEF1A2-SCF complex formation with active form of GSK3β and neddylated Cul1. Conversely, genetic ablation of EEF1A2 and PTEN, activation of AKT, inhibition of GSK3β, expression of Aurora-A phosphodeficient-mutant attenuates the Aurora-A protein degradation which is corroborated in Aurora-A overexpressing mouse mammary carcinomas and human breast carcinomas. This study identifies a novel mechanism of Aurora-A protein degradation mediated eEF1A2-PTEN-GSK3β pathway and provides a framework for the discovery of Aurora-A therapeutic targets in breast cancer that harbors deficiency of PTEN tumor suppressor pathway.

Citation Format: Treekitkarnmongkol W, Solis LM, Kai K, Thompson AM, Tian W, Wistuba II, Sasai K, Jltsumori Y, Sahin AA, Hawke DH, Lee JM, Qin L, Bawa-Khalfe T, Rad R, Wong KK, Abbott CM, Katayama H, Sen S. eEF1A2 facilitates PTEN-GSK3β mediated Aurora-A protein degradation during S-G2 phase inactivated in PTEN-deficient breast cancer [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 P1-05-05.

The Ozone Water-Land Environmental Transition Study (OWLETS): An Innovative Strategy for Understanding Chesapeake Bay Pollution Events

Coastal regions have historically represented a significant challenge for air quality investigations due to water-land boundary transition characteristics and a paucity of measurements available over water. Prior studies have identified the formation of high levels of ozone over water bodies, such as the Chesapeake Bay, that can potentially recirculate back over land to significantly impact populated areas. Earth-observing satellites and forecast models face challenges in capturing the coastal transition zone where small-scale meteorological dynamics are complex and large changes in pollutants can occur on very short spatial and temporal scales. An observation strategy is presented to synchronously measure pollutants 'over-land' and 'over-water' to provide a more complete picture of chemical gradients across coastal boundaries for both the needs of state and local environmental management and new remote sensing platforms. Intensive vertical profile information from ozone lidar systems and ozonesondes, obtained at two main sites, one over land and the other over water, are complemented by remote sensing and in-situ observations of air quality from ground-based, airborne (both personned and unpersonned), and shipborne platforms. These observations, coupled with reliable chemical transport simulations, such as the NOAA National Air Quality Forecast Capability (NAQFC), are expected to lead to a more fully characterized and complete land-water interaction observing system that can be used to assess future geostationary air quality instruments, such as the NASA Tropospheric Emissions: Monitoring of Pollution (TEMPO) as well as current low earth orbiting satellites, such as the European Space Agency's Sentinel 5-Precursor (S5-P) with its Tropospheric Monitoring Instrument (TROPOMI).

Quantifying stratosphere-troposphere transport of ozone using balloon-borne ozonesondes, radar windprofilers and trajectory models

In a series of 10-day campaigns in Ontario and Quebec, Canada, between 2005 and 2007, ozonesondes were launched twice daily in conjunction with continuous high-resolution wind-profiling radar measurements. Windprofilers can measure rapid changes in the height of the tropopause, and in some cases follow stratospheric intrusions. Observed stratospheric intrusions were studied with the aid of a Lagrangian particle dispersion model and the Canadian operational weather forecast system. Definite stratosphere-troposphere transport (STT) events occurred approximately every 2-3 days during the spring and summer campaigns, whereas during autumn and winter, the frequency was reduced to every 4-5 days. Although most events reached the lower troposphere, only three events appear to have significantly contributed to ozone amounts in the surface boundary layer. Detailed calculations find that STT, while highly variable, is responsible for an average, over the seven campaigns, of 3.1% of boundary layer ozone (1.2 ppb), but 13% (5.4 ppb) in the lower troposphere and 34% (22 ppb) in the middle and upper troposphere, where these layers are defined as 0-1 km, 1-3 km, and 3-8 km respectively. Estimates based on counting laminae in ozonesonde profiles, with judicious choices of ozone and relative humidity thresholds, compare moderately well, on average, with these values. The lamina detection algorithm is then applied to a large dataset from four summer ozonesonde campaigns at 18 North American sites between 2006 and 2011. The results show some site-to-site and year-to-year variability, but stratospheric ozone contributions average 4.6% (boundary layer), 15% (lower troposphere) and 26% (middle/upper troposphere). Calculations were also performed based on the TOST global 3D trajectory-mapped ozone data product. Maps of STT in the same three layers of the troposphere suggest that the STT ozone flux is greater over the North American continent than Europe, and much greater in winter and spring than in summer or fall. When averaged over all seasons, magnitudes over North America show similar ratios between levels to the previous calculations, but are overall 3-4 times smaller. This may be because of limitations (trajectory length and vertical resolution) to the current TOST-based calculation.

Ozonesonde Quality Assurance: The JOSIE-SHADOZ (2017) Experience

The ozonesonde is a small balloon-borne instrument that is attached to a standard radiosonde to measure profiles of ozone from the surface to 35 km with ~100-m vertical resolution. Ozonesonde data constitute a mainstay of satellite calibration and are used for climatologies and analysis of trends, especially in the lower stratosphere where satellites are most uncertain. The electrochemical-concentration cell (ECC) ozonesonde has been deployed at ~100 stations worldwide since the 1960s, with changes over time in manufacture and procedures, including details of the cell chemical solution and data processing. As a consequence, there are biases among different stations and discontinuities in profile time-series from individual site records. For 22 years the Jülich [Germany] Ozone Sonde Intercomparison Experiment (JOSIE) has periodically tested ozonesondes in a simulation chamber designated the World Calibration Centre for Ozonesondes (WCCOS) by WMO. In October-November 2017 a JOSIE campaign evaluated the sondes and procedures used in SHADOZ (Southern Hemisphere Additional Ozonesondes), a 14-station sonde network operating in the tropics and subtropics. A distinctive feature of the 2017 JOSIE was that the tests were conducted by operators from eight SHADOZ stations. Experimental protocols for the SHADOZ sonde configurations, which represent most of those in use today, are described, along with preliminary results. SHADOZ stations that follow WMO-recommended protocols record total ozone within 3% of the JOSIE reference instrument. These results and prior JOSIEs demonstrate that regular testing is essential to maintain best practices in ozonesonde operations and to ensure high-quality data for the satellite and ozone assessment communities.

Taehwa Research Forest: A receptor site for severe domestic pollution events in Korea during 2016

During the May-June 2016 International Cooperative Air Quality Field Study in Korea (KORUS-AQ), light synoptic meteorological forcing facilitated Seoul metropolitan pollution outflow to reach the remote Taehwa Research Forest (TRF) site and cause regulatory exceedances of ozone on 24 days. Two of these severe pollution events are thoroughly examined. The first, occurring on 17 May 2016, tracks transboundary pollution transport exiting eastern China and the Yellow Sea, traversing the Seoul Metropolitan Area (SMA), and then reaching TRF in the afternoon hours with severely polluted conditions. This case study indicates that although outflow from China and the Yellow Sea were elevated with respect to chemically unperturbed conditions, the regulatory exceedance at TRF was directly linked in time, space, and altitude to urban Seoul emissions. The second case studied, occurring on 09 June 2016, reveals that increased levels of biogenic emissions, in combination with amplified urban emissions, were associated with severe levels of pollutions and a regulatory exceedance at TRF. In summary, domestic emissions may be causing more pollution than by trans-boundary pathways, which have been historically believed to be the major source of air pollution in South Korea. The case studies are assessed with multiple aircraft, model (photochemical and meteorological) simulations, in-situ chemical sampling, and extensive ground-based profiling at TRF. These observations clearly identify TRF and the surrounding rural communities as receptor sites for severe pollution events associated with Seoul outflow, which will result in long-term negative effects to both human health and agriculture in the affected areas.

OncotypeDX Recurrence Score Does Not Predict Nodal Burden in Clinically Node Negative Breast Cancer Patients

BACKGROUND

OncotypeDX recurrence score (RS)^® has been found to predict recurrence and disease-free survival in patients with node negative breast cancer. Whether RS is useful in guiding locoregional therapy decisions is unclear. We sought to evaluate the relationship between RS and lymph node burden.

METHODS

Patients with invasive breast cancer who underwent sentinel lymph node dissection from 2010 to 2015 were identified from a prospectively maintained database. Patients were excluded if they were clinically node positive or if they received neoadjuvant chemotherapy. RS was classified as low (< 18), intermediate (18-30), or high (> 30). The association between RS, lymph node burden, and disease recurrence was evaluated. Statistical analyses were performed in R version 3.4.0; p < 0.05 was considered significant.

RESULTS

A positive SLN was found in 168 (15%) of 1121 patients. Completion axillary lymph node dissection was performed in 84 (50%) of SLN-positive patients. The remaining 84 (50%) patients had one to two positive SLNs and did not undergo further axillary surgery. RS was low in 58.5%, intermediate in 32.6%, and high in 8.9%. RS was not associated with a positive SLN, number of positive nodes, maximum node metastasis size, or extranodal extension. The median follow-up was 23 months. High RS was not associated with locoregional recurrence (p = 0.07) but was significantly associated with distant recurrence (p = 0.0015).

CONCLUSIONS

OncotypeDX RS is not associated with nodal burden in women with clinically node-negative breast cancer, suggesting that RS is not useful to guide decisions regarding extent of axillary surgery for these patients.

Multidisciplinary Intraoperative Assessment of Breast Specimens Reduces Number of Positive Margins

BACKGROUND

Successful breast-conserving surgery requires achieving negative margins. At our institution, the whole surgical specimen is imaged and then serially sectioned with repeat imaging. A multidisciplinary discussion then determines need for excision of additional margins. The goal of this study was to determine the benefit of each component of this approach in reducing the number of positive margin.

METHODS

This single-institution, prospective study included ten breast surgical oncologists who were surveyed to ascertain whether they would have taken additional margins based their review of whole specimen images (WSI) and review of serially sectioned images (SSI). These results were compared with the multidisciplinary decisions (MDD) and pathology results. Margin status was defined using consensus guidelines.

RESULTS

One hundred surveys were completed. Margins on the original specimen were positive or close in 21%. After WSI, surgeons reported that they would have taken additional margins in 26 cases, reducing the number of positive/close margins from 21 to 13% (p < 0.001). After SSI, 52 would have taken additional margins; however, the number of positive/close margins remained 13%. MDD resulted in additional margins taken in 56 cases, reducing the number of positive/close margins to 7% (p < 0.001 compared with SSI).

CONCLUSIONS

While surgeon review of specimen radiographs can decrease the number of positive or close margins from 21 to 13%, more rigorous multidisciplinary, intraoperative margin assessment reduces the number of close or positive margins to 7%.

Characterizing Global Ozonesonde Profile Variability from Surface to the UT/LS with a Clustering Technique and MERRA-2 Reanalysis

Our previous studies employing the self-organizing map (SOM) clustering technique to ozonesonde data have found significant links among meteorological and chemical regimes, and the shape of the ozone (O3) profile from the troposphere to the lower stratosphere. These studies, which focused on specific northern hemisphere mid-latitude geographical regions, demonstrated the advantages of SOM clustering by quantifying O3 profile variability and the O3/meteorological correspondence. We expand SOM to a global set of ozonesonde profiles spanning 1980-present from 30 sites to summarize the connections among O3 profiles, meteorology, and chemistry, using the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) reanalysis and other ancillary data. Four clusters of O3 mixing ratio profiles from the surface to the upper troposphere/lower stratosphere (UT/LS) are generated for each site, which show dominant profile shapes and typical seasonality (or lack thereof) that generally correspond to latitude (i.e. Tropical, Subtropical, Mid-Latitude, Polar). Examination of MERRA-2 output reveals a clear relationship among SOM clusters and covarying meteorological fields (geopotential height, potential vorticity, and tropopause height) for Polar and Mid-latitude sites. However, these relationships break down within ±30° latitude. Carbon monoxide satellite data, along with velocity potential, a proxy for convection, calculated from MERRA-2 wind fields assist characterization of the Tropical and Subtropical sites, where biomass burning and convective transport linked to the Madden-Julian Oscillation (MJO) dominate O3 variability. In addition to geophysical characterization of O3 profile variability, these results can be used to evaluate chemical transport model output and satellite measurements of O3.

First Reprocessing of Southern Hemisphere ADditional OZonesondes (SHADOZ) Profile Records: 3. Uncertainty in Ozone Profile and Total Column

Reprocessed ozonesonde data from eight SHADOZ (Southern Hemisphere ADditional OZonesondes) sites have been used to derive the first analysis of uncertainty estimates for both profile and total column ozone (TCO). The ozone uncertainty is a composite of the uncertainties of the individual terms in the ozone partial pressure (PO3) equation, those being the ozone sensor current, background current, internal pump temperature, pump efficiency factors, conversion efficiency, and flow-rate. Overall, PO3 uncertainties (ΔPO3) are within 15% and peak around the tropopause (15±3km) where ozone is a minimum and ΔPO3 approaches the measured signal. The uncertainty in the background and sensor currents dominate the overall ΔPO3 in the troposphere including the tropopause region, while the uncertainties in the conversion efficiency and flow-rate dominate in the stratosphere. Seasonally, ΔPO3 is generally a maximum in the March-May, with the exception of SHADOZ sites in Asia, for which the highest ΔPO3 occurs in September-February. As a first approach, we calculate sonde TCO uncertainty (ΔTCO) by integrating the profile ΔPO3 and adding the ozone residual uncertainty, derived from the McPeters and Labow [2012] 1-σ ozone mixing ratios. Overall, ΔTCO are within ±15 DU, representing ~5-6% of the TCO. TOMS and OMI satellite overpasses are generally within the sonde ΔTCO. However, there is a discontinuity between TOMS v8.6 (1998-2004/09) and OMI (2004/10-2016) TCO on the order of 10DU that accounts for the significant 16DU overall difference observed between sonde and TOMS. By comparison, the sonde-OMI absolute difference for the eight stations is only ~4DU.

Abstract P4-15-10: Second breast events after DCIS: Where, what and when?

Background: Detection and diagnosis of ductal carcinoma in situ has substantially increased since the widespread use of mammographic screening with the incidence of DCIS increasing between 1975 from 5.8 per 100,000 to 33.8 per 100,000 women in 2010. While surgical resection of DCIS remains the main treatment, outcomes in terms of in breast re-occurrence or contralateral disease are unpredictable. Recently, three large clinical trials of active surveillance versus standard of care have been initiated. We sought to compare the clinical, imaging, histopathological features and treatment of DCIS for contemporary patients who subsequently developed a second in situ or invasive breast lesion among women treated within a single institution.

Methods: A contemporary prospective cohort study comprising 2,509 women treated for DCIS between 2000 and 2014 was examined for diagnostic imaging, surgery, pathology, adjuvant treatment and second breast events. Patients with primary bilateral DCIS or a bilateral second event were excluded as were patients with antecedent invasive breast cancer. Patients were grouped into two populations based on ipsilateral and contralateral second breast event.

Results: Amongst 2,509 women treated for DCIS between 2000 and 2014, of whom 146 had a second breast event (5.8%). 77 (52.7% of events, 3.07% overall) developed an ipsilateral second breast event (37 DCIS, 40 invasive breast cancer) and 69 (47.3%, 2.75%) patients developed a contralateral second breast lesion (34 DCIS, 35 invasive breast cancer). Patients who developed a contralateral second event were older than those who developed an ipsilateral second event (58 years vs. 52 years, p=0.003). Patients receiving segmental mastectomies were more likely to develop an ipsilateral second event than a contralateral event (85.7% vs. 60.9%, p=0.001). Patients who developed a second contralateral breast event were significantly older at diagnosis (63 years vs. 58 years, p=0.003). There was no significant difference in the number of (69 vs. 77) or time between contralateral and ipsilateral second breast events (5.2 years and 5.1 years, p=0.8) nor in the number of patients with invasive or in situ second events (75 vs. 71). Patients with ipsilateral second breasts events were more likely to undergo bilateral mastectomy than those with contralateral second events (15 vs. 2, p=0.003).

Conclusions: Following standard of care treatment for DCIS, 1 in 20 women develop further DCIS or invasive disease at a median of 5 years with very similar proportions of ipsilateral or contralateral and DCIS or invasive disease. Current trials of active surveillance should consider a median 5 years follow up as a critical time point for reporting results.

Key Words: Ductal carcinoma in situ, invasive breast cancer, population-based cohort, surgery, radiotherapy, endocrine therapy.

Citation Format: King LM, Yi M, Krishnamurthy S, Hunt KK, Thompson AM. Second breast events after DCIS: Where, what and when? [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 P4-15-10.

Abstract P6-03-05: Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer

Background: Image-guided percutaneous needle biopsy of the breast is a common procedure. In breast cancer patients (pts) undergoing core biopsies and surgical resection on the same day, the rate of tumor cell displacement along the needle track has been reported to be up to 50%. However, the clinical significance of this finding in triple negative breast cancer (TNBC) patients (pts) undergoing serial biopsies while receiving neoadjuvant chemotherapy (NACT) is unknown. Here we report the incidence of needle-track seeding (NTS) in a cohort of TNBC pts enrolled on a molecular triaging protocol involving serial biopsies of the index breast lesion.

Methods: We reviewed the clinical records of 144 consecutive TNBC pts enrolled on a molecular triaging protocol at MD Anderson Cancer Center. Per protocol, all pts underwent a pre-treatment research biopsy and were initiated on anthracycline based NACT (AC). Pts with inadequate response to front-line NACT were encouraged to undergo additional biopsies of the index breast lesion prior to switching therapies. Serial breast ultrasound (US) was performed to monitor therapeutic response and incidental evidence of needle-track seeding noted on US was documented.

Results: Clinicopathological characteristics of the pts are summarized in Table 1. 89% (128/144) of pts had a diagnostic breast biopsy done at another center prior to presenting at MDACC. To date, we have performed 209 US guided biopsies of index breast lesions in 144 pts. 92% (193/209) of these biopsies were done mainly for research purposes. 1.4% (2/144) of pts were found to have evidence of NTS on follow up US. The first pt had a T1N0 (1.9cm), grade 3, invasive ductal carcinoma (IDC) at diagnosis. She underwent a diagnostic biopsy followed by a research biopsy before initiating AC. She was found to have NTS as well as progression of disease (PD) on follow up US after 2 cycles of AC. The second pt had a T2N0 (3cm), grade 3 IDC at diagnosis. She underwent a diagnostic biopsy at another center, followed by a research biopsy before initiating AC. Like the first pt, she was found to have NTS and PD on follow up US after 2 cycles of AC. Both pts are currently on neoadjuvant clinical trials of novel agents.

Conclusion: The rate of NTS detected on US in TNBC pts undergoing serial biopsies of index breast lesions while receiving NACT is low and further studies are needed to determine the impact of serial biopsies on long term outcomes in TNBC.

Table 1: Patient CharacteristicsCharacteristicN=144Age - Median (years, interquartile range)55 (46-62)Tumor Size Mean (cm, standard deviation)3.4 (2.2)T1 – n(%)35 (24)T2 – n(%)89 (62)T3 – n(%)19 (13)T4 – n(%)1 (1)Clinical Nodal Status Negative – n(%)74 (51)Positive – n(%)70 (49)Grade 1 – n(%)1 (1)2 – n(%)17 (12)3 – n(%)124 (86)Unknown – n(%)2 (1)Histologic Subtype Invasive ductal carcinoma – n(%)121 (84)Invasive lobular carcinoma – n(%)2 (1)Mixed ductal and lobular carcinoma – n(%)3 (2)Metaplastic carcinoma – n(%)13 (9)Not specified – n(%)5 (3)Laterality Right – n(%)72 (50)Left – n(%)72 (50)

Citation Format: Yam C, Santiago L, Candelaria RP, Adrada BE, Rauch GM, Hess KR, Litton JK, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Huo L, Thompson AM, Gilcrease MZ, Symmans WF, Moulder SL, Yang W. Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer [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 P6-03-05.

Abstract P4-15-02: Impact of radiotherapy and endocrine therapy on further events: Final multivariate analysis of a prospective, national cohort study of screen detected ductal carcinoma in situ (DCIS) of the breast

Key words: DCIS, radiotherapy, endocrine therapy, survival, surgical margins

Background:

The benefits and risks of breast screening remain controversial, with particular concern that ductal carcinoma in situ (DCIS) may be over-diagnosed and over-treated. There is little prospective data on treatment or outcomes for screen detected DCIS.

Methods:

A prospective cohort of non-invasive lesions diagnosed through the United Kingdom National Health Service Breast Screening Programme (NHSBSP) (1 April 2003 to 31 March 2012) was linked to national databases and case note review to analyse patterns of care, recurrence and mortality.

Results:

Screen-detected DCIS in 9938 women was analysed, 33% (9938/30041) of women with a final diagnosis of non-invasive breast neoplasia diagnosed through the NHSBSP over the same time.

The patients (mean age was 60 years: range 46-87 years) were treated by breast conservation surgery (BCS; 7007; 70.5%) or mastectomy (2931). At 64 months median follow up, 697 (6.8%) had further DCIS or invasive breast cancer after BCS (7.8%) or mastectomy (4.5%) (p&lt;0.001) and 228 women (2.3%) developed contralateral malignancy.

Breast radiotherapy (RT) after BCS (4363/7007; 62%) was associated with a 3.1% absolute reduction in any ipsilateral DCIS or invasive cancer (No RT: 7.2% vs RT: 4.1% (p&lt;0.001) and a 1.9% absolute reduction for ipsilateral invasive breast recurrence (No RT: 3.8% vs RT: 1.9% (p&lt;0.001), independent of excision margin width or size of DCIS. Women who did not receive RT after BCS had more ipsilateral events (p=0.008) when the radial excision margin was &lt;2mm. RT was rarely used after mastectomy for DCIS (33 women). Adjuvant endocrine therapy (prescribed for 1208/9938; 12.2%) was associated with a reduction in any ipsilateral recurrence, independent of whether women did (HR 0.57: 95% CI 0.41 - 0.80) or did not (HR 0.68: 95% CI 0.51 - 0.91) receive RT after BCS.

Among 321 (3.2%) women who died, 46 deaths (0.5%; 14.3% of all deaths) were attributed to invasive breast cancer. Death from breast cancer was uncommon and outnumbered 5:1 by death due to other causes. RT after BCS was associated with a non-significant 0.2% absolute reduction in breast cancer mortality. However, women who developed invasive breast cancer had a worse survival than those with further DCIS (p&lt;0.001).

Conclusions:

Recurrent DCIS or invasive cancer is uncommon following screen detected DCIS treated by surgery and adjuvant therapy. Both RT and endocrine therapy following surgery were associated with a significant reduction in further DCIS and invasive disease, but not breast cancer mortality, within 5 years of diagnosis. This study quantifies the benefits of radiotherapy and endocrine therapy to inform decision making in the management of screen detected DCIS.

Citation Format: Thompson AM, Clements K, Cheung S, Pinder SE, Lawrence G, Sawyer E, Kearins O, Ball GR, Tomlinson I, Hanby AM, Thomas J, Maxwell AJ, Wallis MG, Dodwell DJ. Impact of radiotherapy and endocrine therapy on further events: Final multivariate analysis of a prospective, national cohort study of screen detected ductal carcinoma in situ (DCIS) of the breast [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 P4-15-02.

Abstract P4-15-04: A longitudinal cohort study to identify risk factors for the development of invasive cancer in unresected DCIS

Background: The variable natural history of ductal carcinoma in situ (DCIS) remains poorly understood. Randomized trials of active surveillance versus guideline concordant care are currently underway: the Comparison of Operative to Monitoring and Endocrine Therapy (COMET) trial in the US, LOw Risk dcIS (LORIS) trial in the UK and Low Risk Dcis (LORD) in Europe. Given this context, we examined the outcomes of a contemporary group of women with DCIS who did not undergo initial surgical resection.

Methods: A longitudinal cohort of women diagnosed with DCIS on needle biopsy who did not undergo initial surgical excision for ≥1 year were identified through the Cancer Registry with case note and death certificate review for subsequent outcomes.

Results: Eighty-nine eligible women with DCIS alone diagnosed on needle biopsy (most with 14-gauge core needle biopsy) between 1998 and 2010 were identified. The mean age at diagnosis was 72 years (range 44-94 years) with mean follow-up (diagnosis to death, invasive disease or last review) of 62 months (range 12-180 months). Twenty-nine women (33%) developed histologically proven invasive breast cancer, 28 at the site of the initial DCIS biopsy, after a mean interval of 54 months (range 12-144 months): 14/29 (48%) women originally had high grade DCIS, 10/31 (32%) intermediate grade and 3/17 (18%) low grade DCIS (initial grade not known in 12). Time to detect a diagnosis of invasive breast cancer was associated with initial grade of DCIS (p=0.0016, log-rank test): after mean intervals of 41 months (high grade), 69 months (intermediate grade) and 78 months (low grade) respectively. Younger age was associated with development of invasive disease (p&lt;0.003, Mann-Whitney U-Test). High grade (grade 3) invasive breast cancer exclusively occurred in women with a prior diagnosis of high grade DCIS. Invasion was more frequent in lesions with calcification as the predominant feature than those without (23/50 v. 5/25; p&lt;0.05, Fisher exact test). Forty-four women were prescribed endocrine therapy, use of which was associated with a lower rate of invasive breast cancer (p&lt;0.05). Ultimately 18 women underwent surgery, 17 for invasive cancer. The mean interval from DCIS diagnosis to death was 76 months for those who developed invasive cancer; 48/89 women died, 12 had a certified cause of death as breast cancer.

Conclusion: High grade DCIS, mammographic microcalcification and lack of endocrine therapy were associated with progression to invasion. The findings suggest surgical excision of high grade DCIS should continue but provides support that women with DCIS features which include low grade should be considered for the COMET, LORIS or LORD active surveillance trials.

Citation Format: Maxwell AJ, Clements K, Hilton B, Dodwell DJ, Evans A, Olive K, Pinder SE, Thomas J, Matthew WG, Thompson AM. A longitudinal cohort study to identify risk factors for the development of invasive cancer in unresected DCIS [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 P4-15-04.

Abstract P1-07-22: Androgen receptor positivity is associated with nodal disease in triple negative breast cancer

Background: Gene expression profiling (GEP) has identified several molecularly distinct subtypes of triple negative breast cancer (TNBC). Currently, GEP-based molecular diagnostics are not routinely used in clinical decision making due to the lack of proven benefit, costs involved and long turnaround time. However, two molecularly distinct subtypes of TNBC, the luminal androgen receptor (AR) and mesenchymal subtypes, have surrogate CLIA-certified immunohistochemical (IHC) markers, AR and vimentin (VM), respectively, which have the potential for application in the clinic. Here we report the rates of AR and VM positivity and their association with clinicopathological characteristics in a cohort of TNBC pts receiving NACT.

Methods: As part of an ongoing molecular triaging protocol, 144 pts with stage I-III TNBC underwent a pretreatment biopsy for molecular characterization (MC) prior to initiating neoadjuvant chemotherapy (NACT). IHC for AR and VM were performed using commercially available antibodies. AR+ and VM+ were defined as ≥10% and ≥50% staining, respectively. Pts were randomized 2:1 to know (intervention arm, n=93) and not know (control arm, n=51) the MC results. The charts of pts randomized to the intervention arm were reviewed. Categorical variables were analyzed using Fisher's exact test. Ordinal and continuous variables were analyzed using the Wilcoxon rank-sum test and Student's t test as appropriate.

Results: 31% (29/93) and 16% (15/93) of pts were AR+ and VM+, respectively. Only 4% (4/93) of pts were both AR+ and VM+. Clinicopathological characteristics are summarized in Table 1. AR+ pts were more likely to have clinically node positive disease as compared to AR- pts (66% vs 34%, p=0.007). There were no significant differences in clinical tumor size or grade between AR+ and AR- pts. VM+ and VM- pts had similar clinicopathological characteristics.

Conclusion: Pts with AR+ TNBC were more likely to have node positive disease. The impact of AR+ on long term outcomes should be investigated in prospective studies.

Table 1: Association between patient characteristics and AR/VM status AR  VM   AR+ (n=29)AR- (n=64)p-valueVM+ (n=15)VM- (n=78)p-valueAge - Median (years, interquartile range)58 (48-65)52 (46-61)0.05855 (48-64)56 (47-62)0.88Clinical Tumor Size      Mean (cm, standard deviation)3.5 (1.8)3.0 (1.8)0.2872.7 (1.7)3.3 (1.9)0.31T1 – n(%)5 (17)21 (33)0.2307 (47)19 (24)0.098T2 – n(%)21 (72)36 (56) 7 (47)50 (64) T3 – n(%)3 (10)7 (11) 1 (7)9 (12) Clinical Nodal Status      Negative – n(%)10 (34)42 (66)0.0078 (53)44 (56)1.00Positive – n(%)19 (66)22 (34) 7 (47)34 (44) Grade      2 – n(%)6 (21)5 (8)0.0763 (20)8 (10)0.293 – n(%)23 (79)59 (92) 12 (80)70 (90) 

Citation Format: Yam C, Huo L, Hess KR, Litton JK, Yang W, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Thompson AM, Santiago L, Candelaria RP, Rauch GM, Adrada BE, Symmans WF, Gilcrease MZ, Moulder SL. Androgen receptor positivity is associated with nodal disease in triple negative breast cancer [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 P1-07-22.

Ozone Variability and Anomalies Observed during SENEX and SEAC4RS Campaigns in 2013

Tropospheric ozone variability occurs because of multiple forcing factors including surface emission of ozone precursors, stratosphere-to-troposphere transport (STT), and meteorological conditions. Analyses of ozonesonde observations made in Huntsville, AL, during the peak ozone season (May to September) in 2013 indicate that ozone in the planetary boundary layer was significantly lower than the climatological average, especially in July and August when the Southeastern United States (SEUS) experienced unusually cool and wet weather. Because of a large influence of the lower stratosphere, however, upper-tropospheric ozone was mostly higher than climatology, especially from May to July. Tropospheric ozone anomalies were strongly anti-correlated (or correlated) with water vapor (or temperature) anomalies with a correlation coefficient mostly about 0.6 throughout the entire troposphere. The regression slopes between ozone and temperature anomalies for surface up to mid-troposphere are within 3.0-4.1 ppbv·K-1. The occurrence rates of tropospheric ozone laminae due to STT are ≥50% in May and June and about 30% in July, August and September suggesting that the stratospheric influence on free-tropospheric ozone could be significant during early summer. These STT laminae have a mean maximum ozone enhancement over the climatology of 52±33% (35±24 ppbv) with a mean minimum relative humidity of 2.3±1.7%.

Using observations and source specific model tracers to characterize pollutant transport during FRAPPÉ and DISCOVER-AQ

Transport is a key parameter in air quality research and plays a dominant role in the Colorado Northern Front Range Metropolitan Area (NFRMA), where terrain induced flows and recirculation patterns can lead to vigorous mixing of different emission sources. To assess different transport processes and their connection to air quality in the NFRMA during the FRAPPÉ and DISCOVER-AQ campaigns in summer 2014, we use the Weather Research and Forecasting Model with inert tracers. Overall, the model represents well the measured winds and the inert tracers are in good agreement with observations of comparable trace gas concentrations. The model tracers support the analysis of surface wind and ozone measurements and allow for the analysis of transport patterns and interactions of emissions. A main focus of this study is on characterizing pollution transport from the NFRMA to the mountains by mountain-valley flows and the potential for recirculating pollution back into the NFRMA. One such event on 12 August 2014 was well captured by the aircraft and is studied in more detail. The model represents the flow conditions and demonstrates that during upslope events, frequently there is a separation of air masses that are heavily influenced by oil and gas emissions to the North and dominated by urban emissions to the South. This case study provides evidence that NFRMA pollution not only can impact the nearby Foothills and mountain areas to the East of the Continental Divide, but that pollution can "spill over" into the valleys to the West of the Continental Divide.

Abstract P4-02-07: Preoperative assessment of breast cancer survival using ultrasound diameter and shear wave elastography

This abstract was not presented at the symposium.

Abstract PD3-04: Which measure of the interim changes in breast tumoral volume at breast MRI in response to neoadjuvant chemotherapy best predicts final pathological response?

BACKGROUND: Interim changes in breast tumour volume at magnetic resonance imaging (MRI) can predict ultimate response to neoadjuvant chemotherapy (NAC), but there is little data on the best measure of volumetric change.

PURPOSE: To assess whether changes in measurements of semi-automated enhancing tumour volume (ETV) or fully automated functional tumour volume (FTV) between baseline and interim contrast-enhanced MRI are equivalent in predicting ultimate pathological response to neoadjuvant chemotherapy (NAC) for primary breast cancer, assessed using the residual cancer burden (RCB) score.

MATERIALS & METHODS: 78 patients undergoing treatment with NAC for primary breast cancer underwent contrast-enhanced MRI on a 1.5T or 3.0T MRI scanner using a dedicated bilateral breast coil before and after two or three cycles of NAC. Image analysis was performed using either semi-automated, user-defined thresholding (ITK-Snap; ETV) or fully-automated (Siemens SyngoVia BreVis; FTV) approaches. For ETV, the two-minute post-contrast subtracted volumes were analysed, with enhancing pixels thresholded to define tumour volume. FTV was measured using a manufacturer default setting of 50% enhancement threshold, relative to pre-contrast signal intensity, to define tumour volume. ETV intra-observer reproducibility was assessed by repeat analysis one month after initial analysis and a second observer also repeated the measure. Coefficient of reproducibility (CoR) and intraclass correlation coefficents (ICC) were calculated for intra- and inter-observer repeatability.

ETV and FTV percentage reduction between baseline and interim examinations was compared with final pathological response, as assessed using the residual cancer burden (RCB) score on resected cancer specimens.

Correlation of the two volumetric measures was performed using a Pearson Intra-class Correlation Coefficient (ICC) and pair-wise comparisons of ETV and FTV changes between RCB groups carried out using a Mann-Whitney U test. All statistical assessment was performed using SPSS, v21, with p&lt;0.05 considered significant.

RESULTS: There was significant correlation between ETV and FTV (ICC= 0.744, p&lt;0.05). Intra and inter observer reproducibility for ETV was excellent, with ICC 0.940 and 0.861 respectively and corresponding CoRs of 11.6% and 14.8%.

Average percentage reductions in ETV for each pathological response category were: pCR 96.4% (n=12), RCB-I 66.6% (n=10), RCB-II 62.9% (n=39) and RCB-III 27.3% (n=17). Corresponding values for FTV were 88.8%, 70.6%, 54.6% and 20.8%.

Significant differences in percentage ETV changes were found for pCR vs. RCB-I (p&lt;0.008), II (p&lt;0.001) & III (p&lt;0.001) and RCB-II vs. RCB-III (p&lt;0.001). For FTV, significant differences were measured only for pCR vs. RCB-II & III (p&lt;0.001).

CONCLUSION: changes in the semi-automated ETV measuement between baseline and interim MRI may provide more useful predictive information on final pathological response to NAC than FTV, as the changes are better able to discriminate between pCR and minimal residual disease (RCB-I). The ability to confidently predict pCR versus all other residual disease categories could facilitate planning of enhanced approaches to surgical management.

Citation Format: Thompson AM, Vinnicombe SJ, Waugh SA, Purdie CA, Evans AJ, Brunton T, Fuller-Pace FV. Which measure of the interim changes in breast tumoral volume at breast MRI in response to neoadjuvant chemotherapy best predicts final pathological response? [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 PD3-04.

Abstract P1-11-04: Looking beyond the margins: Economic costs and complications associated with repeated breast-conserving surgeries

Background: Although considerable attention has been drawn to the problem of repeat breast-conserving surgery (BCS), the costs and complications due to these additional operations are not well-characterized. In this work, a retrospective review of insurance claims data for BCS patients was performed to assess complications and economic outcomes.

Methods: Private claims data were analyzed for 9,837 women undergoing BCS for breast carcinoma between January 2010 and December 2013. Patients enrolled in insurance plans in IL, TX, NM, and OK were included. Patients undergoing a second open breast surgery (mastectomy or BCS) within 90 days of the initial BCS were classified as having a repeat surgery. Complications were identified via a set of 8 CPT and 25 ICD9 diagnosis and procedure codes related to breast cancer treatment. The analysis included these complications and the total cost of all allowed healthcare claims within two years following diagnosis.

Results: 7,555/9,837 patients (77% ±0.8%, 95% confidence interval) had one BCS operation, and 2,282 patients (23% ±0.8%) had at least one repeat surgery. The mean patient age was 53 years. Women who underwent an additional operation waited an average of 24 days for the procedure.

The mean two-year total costs for patients undergoing a single BCS was $89,016 (±$1,884), and the cost for patients undergoing a repeat breast surgery was $105,088 (±$3,680; p &lt; 0.0001), $100,637 (±$4,219) for a second BCS and $115,292 (±$7,259) for subsequent mastectomy. The mean added cost due to a repeat surgery was $16,072.

The percentage of patients experiencing at least one complication was 23.6% (±1.0%) for those undergoing one BCS only and 34.8% (±2.0%) for those undergoing a repeat operation (p &lt; 0.0001). Patients undergoing repeated surgery were 88% more likely to experience multiple complications (5.5% ±0.5% vs. 10.4% ±1.3%) and nearly three times as likely to experience fat necrosis (2.5% ±0.4% vs. 7.2% ±1.1%). Infection, hematoma/seroma, and breast pain were the most common complications for patients who did not undergo a repeated surgery (9.9% ±0.7%, 8.7% ±0.6%, 6.9% ±0.6%). For patients undergoing a repeated surgery, infection, hematoma/seroma, and fat necrosis were the most common complications (15.3% ±1.5%, 13.9% ±1.4%, 7.2% ±1.1%).

Conclusions: For the 23% of women undergoing a second operation after BCS, complications were 48% more common, and the mean total cost of surgery was $16,072 more, demonstrating statistically-significant evidence of a patient-centered and fiscal imperative to reduce reoperations in BCS for breast cancer.Background: Although considerable attention has been drawn to the problem of repeat breast-conserving surgery (BCS), the costs and complications due to these additional operations are not well-characterized. In this work, a retrospective review of insurance claims data for BCS patients was performed to assess complications and economic outcomes.

Methods: Private claims data were analyzed for 9,837 women undergoing BCS for breast carcinoma between January 2010 and December 2013. Patients enrolled in insurance plans in IL, TX, NM, and OK were included. Patients undergoing a second open breast surgery (mastectomy or BCS) within 90 days of the initial BCS were classified as having a repeat surgery. Complications were identified via a set of 8 CPT and 25 ICD9 diagnosis and procedure codes related to breast cancer treatment. The analysis included these complications and the total cost of all allowed healthcare claims within two years following diagnosis.

Results: 7,555/9,837 patients (77% ±0.8%, 95% confidence interval) had one BCS operation, and 2,282 patients (23% ±0.8%) had at least one repeat surgery. The mean patient age was 53 years. Women who underwent an additional operation waited an average of 24 days for the procedure.

The mean two-year total costs for patients undergoing a single BCS was $89,016 (±$1,884), and the cost for patients undergoing a repeat breast surgery was $105,088 (±$3,680; p &lt; 0.0001), $100,637 (±$4,219) for a second BCS and $115,292 (±$7,259) for subsequent mastectomy. The mean added cost due to a repeat surgery was $16,072.

The percentage of patients experiencing at least one complication was 23.6% (±1.0%) for those undergoing one BCS only and 34.8% (±2.0%) for those undergoing a repeat operation (p &lt; 0.0001). Patients undergoing repeated surgery were 88% more likely to experience multiple complications (5.5% ±0.5% vs. 10.4% ±1.3%) and nearly three times as likely to experience fat necrosis (2.5% ±0.4% vs. 7.2% ±1.1%). Infection, hematoma/seroma, and breast pain were the most common complications for patients who did not undergo a repeated surgery (9.9% ±0.7%, 8.7% ±0.6%, 6.9% ±0.6%). For patients undergoing a repeated surgery, infection, hematoma/seroma, and fat necrosis were the most common complications (15.3% ±1.5%, 13.9% ±1.4%, 7.2% ±1.1%).

The impact of repeated breast-conserving surgeries BCS, No RepeatRepeat BCSConvert to MastectomyPatients76.8% (7,555)16.2% (1,589)7.0% (693)Mean Two-Year Cost Per Patient$89,016$100,637$115,292Patients with any Complication(s)23.6% (1,783)32.5% (516)40.3% (279)Patients with Infection9.9% (746)14.0% (222)18.3% (127)Patients with Hematoma/Seroma8.7% (655)12.8% (203)16.6% (115)Patients with Breast Pain6.9% (525)7.0% (111)6.1% (42)Patients with Fat Necrosis2.5% (187)7.6% (120)6.5% (45)

Conclusions: For the 23% of women undergoing a second operation after BCS, complications were 48% more common, and the mean total cost of surgery was $16,072 more, demonstrating statistically-significant evidence of a patient-centered and fiscal imperative to reduce reoperations in BCS for breast cancer.

Citation Format: Metcalf LN, Zysk AM, Underwood HR, Edelman G, Vu L, Cittadine AJ, Hyer KB, Thompson AM. Looking beyond the margins: Economic costs and complications associated with repeated breast-conserving surgeries [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 P1-11-04.

Tropospheric ozonesonde profiles at long-term U.S. monitoring sites: 2. Links between Trinidad Head, CA, profile clusters and inland surface ozone measurements

Much attention has been focused on the transport of ozone (O₃) to the Western U.S., particularly given the latest revision of the National Ambient Air Quality Standard (NAAQS) to 70 parts per billion by volume (ppbv) of O₃. This makes defining a "background" O₃ amount essential so that the effects of stratosphere-to-troposphere exchange and pollution transport to this region can be quantified. To evaluate free-tropospheric and surface O₃ in the Western U.S., we use self-organizing maps to cluster 18 years of ozonesonde profiles (940 samples) from Trinidad Head, CA. Two of nine O₃ mixing ratio profile clusters exhibit thin laminae of high O₃ above Trinidad Head. A third, consisting of background (~20 - 40 ppbv) O₃, occurs in ~10% of profiles. The high O₃ layers are located between 1 and 4 km amsl, and reside above a subsidence inversion associated with a northern location of the semi-permanent Pacific subtropical high. Several ancillary data sets are examined to identify the high O₃ sources (reanalyses, trajectories, remotely-sensed carbon monoxide), but distinguishing chemical and stratospheric influences of the elevated O₃ is difficult. There is marked and long-lasting impact of the elevated tropospheric O₃ on high-altitude surface O₃ monitors at Lassen Volcanic and Yosemite National Parks, and Truckee, CA. Days corresponding to the high O₃ clusters exhibit hourly surface O₃ anomalies of +5 - 10 ppbv compared to a climatology; the anomalies can last up to four days. The profile and surface O₃ links demonstrate the importance of regular ozonesonde profiling at Trinidad Head.

Tropospheric ozone change from 1980 to 2010 dominated by equatorward redistribution of emissions

Since 1980, anthropogenic emissions of ozone precursors have decreased in developed regions, but increased in developing regions, particularly East and South Asia, redistributing emissions equatorwards^1-4. Modeling studies have shown that the tropospheric ozone burden (B _O3) is much more sensitive to emission changes in the tropics and Southern Hemisphere (SH) than other regions^5-9. However, the effect of the spatial redistribution of emissions has not been isolated. Here we use a global chemical transport model to consider changes in anthropogenic short-lived emissions from 1980 to 2010, and separate the influence of changes in the spatial distribution of emissions from the total emission increase, on B _O3 and surface ozone. We estimate that the spatial distribution change increased B _O3 by slightly more than the combined influences of changes in the global emission magnitude itself and in global methane. These results are explained by the strong convection, fast reaction rates, and strong NO_x sensitivity in the tropics and subtropics. Emissions increases in Southeast, East, and South Asia may be most important for the B _O3 change. The spatial distribution of emissions has a dominant effect on global tropospheric ozone, suggesting that the future ozone burden will be determined mainly by emissions from the tropics and subtropics.

Formaldehyde column density measurements as a suitable pathway to estimate near-surface ozone tendencies from space

In support of future satellite missions that aim to address the current shortcomings in measuring air quality from space, NASA's Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign was designed to enable exploration of relationships between column measurements of trace species relevant to air quality at high spatial and temporal resolution. In the DISCOVER-AQ data set, a modest correlation (r 2 = 0.45) between ozone (O3) and formaldehyde (CH2O) column densities was observed. Further analysis revealed regional variability in the O3-CH2O relationship, with Maryland having a strong relationship when data were viewed temporally and Houston having a strong relationship when data were viewed spatially. These differences in regional behavior are attributed to differences in volatile organic compound (VOC) emissions. In Maryland, biogenic VOCs were responsible for ~28% of CH2O formation within the boundary layer column, causing CH2O to, in general, increase monotonically throughout the day. In Houston, persistent anthropogenic emissions dominated the local hydrocarbon environment, and no discernable diurnal trend in CH2O was observed. Box model simulations suggested that ambient CH2O mixing ratios have a weak diurnal trend (±20% throughout the day) due to photochemical effects, and that larger diurnal trends are associated with changes in hydrocarbon precursors. Finally, mathematical relationships were developed from first principles and were able to replicate the different behaviors seen in Maryland and Houston. While studies would be necessary to validate these results and determine the regional applicability of the O3-CH2O relationship, the results presented here provide compelling insight into the ability of future satellite missions to aid in monitoring near-surface air quality.

Analysis of the latitudinal variability of tropospheric ozone in the Arctic using the large number of aircraft and ozonesonde observations in early summer 2008

The goal of the paper are to: (1) present tropospheric ozone (O₃) climatologies in summer 2008 based on a large amount of measurements, during the International Polar Year when the Polar Study using Aircraft, Remote Sensing, Surface Measurements, and Models of Climate Chemistry, Aerosols, and Transport (POLARCAT) campaigns were conducted (2) investigate the processes that determine O₃ concentrations in two different regions (Canada and Greenland) that were thoroughly studied using measurements from 3 aircraft and 7 ozonesonde stations. This paper provides an integrated analysis of these observations and the discussion of the latitudinal and vertical variability of tropospheric ozone north of 55°N during this period is performed using a regional model (WFR-Chem). Ozone, CO and potential vorticity (PV) distributions are extracted from the simulation at the measurement locations. The model is able to reproduce the O₃ latitudinal and vertical variability but a negative O3 bias of 6-15 ppbv is found in the free troposphere over 4 km, especially over Canada. Ozone average concentrations are of the order of 65 ppbv at altitudes above 4 km both over Canada and Greenland, while they are less than 50 ppbv in the lower troposphere. The relative influence of stratosphere-troposphere exchange (STE) and of ozone production related to the local biomass burning (BB) emissions is discussed using differences between average values of O₃, CO and PV for Southern and Northern Canada or Greenland and two vertical ranges in the troposphere: 0-4 km and 4-8 km. For Canada, the model CO distribution and the weak correlation (< 30%) of O₃ and PV suggests that stratosphere-troposphere exchange (STE) is not the major contribution to average tropospheric ozone at latitudes less than 70°N, due to the fact that local biomass burning (BB) emissions were significant during the 2008 summer period. Conversely over Greenland, significant STE is found according to the better O₃ versus PV correlation (> 40%) and the higher 75th PV percentile. A weak negative latitudinal summer ozone gradient -6 to -8 ppbv is found over Canada in the mid troposphere between 4 and 8 km. This is attributed to an efficient O₃ photochemical production due to the BB emissions at latitudes less than 65°N, while STE contribution is more homogeneous in the latitude range 55°N to 70°N. A positive ozone latitudinal gradient of 12 ppbv is observed in the same altitude range over Greenland not because of an increasing latitudinal influence of STE, but because of different long range transport from multiple mid-latitude sources (North America, Europe and even Asia for latitudes higher than 77°N).

Ground-based assessment of the bias and long-term stability of fourteen limb and occultation ozone profile data records

The ozone profile records of a large number of limb and occultation satellite instruments are widely used to address several key questions in ozone research. Further progress in some domains depends on a more detailed understanding of these data sets, especially of their long-term stability and their mutual consistency. To this end, we made a systematic assessment of fourteen limb and occultation sounders that, together, provide more than three decades of global ozone profile measurements. In particular, we considered the latest operational Level-2 records by SAGE II, SAGE III, HALOE, UARS MLS, Aura MLS, POAM II, POAM III, OSIRIS, SMR, GOMOS, MIPAS, SCIAMACHY, ACE-FTS and MAESTRO. Central to our work is a consistent and robust analysis of the comparisons against the ground-based ozonesonde and stratospheric ozone lidar networks. It allowed us to investigate, from the troposphere up to the stratopause, the following main aspects of satellite data quality: long-term stability, overall bias, and short-term variability, together with their dependence on geophysical parameters and profile representation. In addition, it permitted us to quantify the overall consistency between the ozone profilers. Generally, we found that between 20-40 km the satellite ozone measurement biases are smaller than ±5 %, the short-term variabilities are less than 5-12% and the drifts are at most ±5% decade^-1 (or even ±3 % decade^-1 for a few records). The agreement with ground-based data degrades somewhat towards the stratopause and especially towards the tropopause where natural variability and low ozone abundances impede a more precise analysis. In part of the stratosphere a few records deviate from the preceding general conclusions; we identified biases of 10% and more (POAM II and SCIAMACHY), markedly higher single-profile variability (SMR and SCIAMACHY), and significant long-term drifts (SCIAMACHY, OSIRIS, HALOE, and possibly GOMOS and SMR as well). Furthermore, we reflected on the repercussions of our findings for the construction, analysis and interpretation of merged data records. Most notably, the discrepancies between several recent ozone profile trend assessments can be mostly explained by instrumental drift. This clearly demonstrates the need for systematic comprehensive multi-instrument comparison analyses.

Frequency and Impact of Summertime Stratospheric Intrusions over Maryland during DISCOVER-AQ (2011): New Evidence from NASA's GEOS-5 Simulations

Aircraft observations and ozonesonde profiles collected on July 14 and 27, 2011, during the Maryland month-long DISCOVER-AQ campaign, indicate the presence of stratospheric air just above the planetary boundary layer (PBL). This raises the question of whether summer stratospheric intrusions (SIs) elevate surface ozone levels and to what degree they influence background ozone levels and contribute to ozone production. We used idealized stratospheric air tracers, along with observations, to determine the frequency and extent of SIs in Maryland during July 2011. On 4 of 14 flight days, SIs were detected in layers that the aircraft encountered above the PBL from the coincidence of enhanced ozone, moderate CO, and low moisture. Satellite observations of lower tropospheric humidity confirmed the occurrence of synoptic scale influence of SIs as do simulations with the GEOS-5 Atmospheric General Circulation Model. The evolution of GEOS-5 stratospheric air tracers agree with the timing and location of observed stratospheric influence and indicate that more than 50% of air in SI layers above the PBL had resided in the stratosphere within the previous 14 days. Despite having a strong influence in the lower free troposphere, these events did not significantly affect surface ozone, which remained low on intrusion days. The model indicates similar frequencies of stratospheric influence during all summers from 2009-2013. GEOS-5 results suggest that, over Maryland, the strong inversion capping the summer PBL limits downward mixing of stratospheric air during much of the day, helping to preserve low surface ozone associated with frontal passages that precede SIs.

CAMx Ozone Source Attribution in the Eastern United States using Guidance from Observations during DISCOVER-AQ Maryland

A Comprehensive Air-Quality Model with Extensions (CAMx) version 6.10 simulation was assessed through comparison with data acquired during NASA's 2011 DISCOVER-AQ Maryland field campaign. Comparisons for the baseline simulation (CB05 chemistry, EPA 2011 National Emissions Inventory) show a model overestimate of NO_y by +86.2% and an underestimate of HCHO by -28.3%. We present a new model framework (CB6r2 chemistry, MEGAN v2.1 biogenic emissions, 50% reduction in mobile NO_x, enhanced representation of isoprene nitrates) that better matches observations. The new model framework attributes 31.4% more surface ozone in Maryland to electric generating units (EGUs) and 34.6% less ozone to on-road mobile sources. Surface ozone becomes more NO_x-limited throughout the eastern United States compared to the baseline simulation. The baseline model therefore likely underestimates the effectiveness of anthropogenic NO_x reductions as well as the current contribution of EGUs to surface ozone.

Tropospheric ozonesonde profiles at long-term U.S. monitoring sites: 1. A climatology based on self-organizing maps

Sonde-based climatologies of tropospheric ozone (O₃) are vital for developing satellite retrieval algorithms and evaluating chemical transport model output. Typical O₃ climatologies average measurements by latitude or region, and season. Recent analysis using self-organizing maps (SOM) to cluster ozonesondes from two tropical sites found clusters of O₃ mixing ratio profiles are an excellent way to capture O₃ variability and link meteorological influences to O₃ profiles. Clusters correspond to distinct meteorological conditions, e.g. convection, subsidence, cloud cover, and transported pollution. Here, the SOM technique is extended to four long-term U.S. sites (Boulder, CO; Huntsville, AL; Trinidad Head, CA; Wallops Island, VA) with 4530 total profiles. Sensitivity tests on k-means algorithm and SOM justify use of 3×3 SOM (nine clusters). At each site, SOM clusters together O₃ profiles with similar tropopause height, 500 hPa height/temperature, and amount of tropospheric and total column O₃. Cluster means are compared to monthly O₃ climatologies. For all four sites, near-tropopause O₃ is double (over +100 parts per billion by volume; ppbv) the monthly climatological O₃ mixing ratio in three clusters that contain 13 - 16% of profiles, mostly in winter and spring. Large mid-tropospheric deviations from monthly means (-6 ppbv, +7 - 10 ppbv O₃ at 6 km) are found in two of the most populated clusters (combined 36 - 39% of profiles). These two clusters contain distinctly polluted (summer) and clean O₃ (fall-winter, high tropopause) profiles, respectively. As for tropical profiles previously analyzed with SOM, O₃ averages are often poor representations of U.S. O₃ profile statistics.

Abstract P3-07-23: CYP2D6 genotype and breast cancer recurrence in tamoxifen treated patients: An evaluation of the importance of loss-of-heterozygosity

Background: Tamoxifen therapy for estrogen receptor positive (ER+) breast cancer reduces recurrence risk by about half. Steady-state concentrations of endoxifen, a potent anti-estrogenic tamoxifen metabolite, are reduced in women whose CYP2D6 genotypes confer poor enzyme function. Many studies have measured associations between genetically impaired CYP2D6 function and tamoxifen resistance. It has been suggested that the subset of studies using DNA extracted from tumor-infiltrated tissue may have been susceptible to genotyping error induced by loss of heterozygosity (LOH); the putative non-differential genotype misclassification may have biased these studies' estimates toward the null. We reviewed the clinical epidemiology studies conducted to date to assess the importance of loss-of-heterozygosity (LOH) at the CYP2D6 locus and its implications for assessing tamoxifen effectiveness.

Methods: We searched for the terms "tamoxifen" and "CYP2D6" in PubMed, including all papers and abstracts through 31 May 2015 on the association of CYP2D6 gene variants and the risk of breast cancer recurrence or mortality. We used a quantitative bias analysis (QBA) to evaluate the importance of genotype misclassification in studies that extracted DNA from tumor-infiltrated tissue. We conducted a random effects meta-analysis to evaluate all studies simultaneously, and within groups according to whether DNA was derived from tumor-infiltrated tissue or non-neoplastic tissue.

Results: Thirty-one studies investigated CYP2D6 genotype and breast cancer recurrence, yielding relative effect estimates ranging from 0.08 to 14. DNA was extracted from blood or non-neoplastic tissue in 21 of these 31 studies (68%), and from tumor-infiltrated tissue in the remaining 10 (32%). Our analysis of the association between variant/variant genotype compared with wildtype/wildtype genotype included 21 of the 31 studies. Sixteen (76%) of these 21 studies extracted DNA from blood or non-neoplastic tissue and five (24%) extracted DNA from tumor-infiltrated tissue. Genotype misclassification parameters for the QBA were estimated from six concordance studies. There was little difference between the effect estimates (EE) and 95% confidence/simulation intervals (95% CI/SI) before and after QBA (EE=1.71, 95%CI=1.24, 2.36, and 1.80 95%SI=1.28, 2.54, respectively). Studies using non-neoplastic DNA had higher variance than those based on tumor-infiltrated tissue DNA, half reported implausibly high EE, and many were susceptible to design and analysis errors that would bias estimates of association away from the null.

Conclusions: We found little relative bias in the summary estimates of association, either overall or when limited to the tumor-infiltrated tissue DNA studies. Three guideline panels, based on robust evidence, recommend against CYP2D6 genotype-guided tamoxifen therapy. Alternatives for optimizing the effectiveness of tamoxifen therapy, such as assuring adherence and persistence, are more likely to achieve clinically important benefits.

Citation Format: Ahern TP, Hertz DL, Damkier P, Ejlertsen B, Hamilton-Dutoit SJ, Rae JM, Regan MM, Thompson AM, Lash TL, Cronin-Fenton DP. CYP2D6 genotype and breast cancer recurrence in tamoxifen treated patients: An evaluation of the importance of loss-of-heterozygosity. [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 P3-07-23.

Abstract P5-07-15: Breast cancer estrogen receptor scoring in tissue microarrays: Specialist breast pathologist versus automation

Rationale: Tissue microarrays (TMAs) have become a valuable resource for biomarker expression in translational research. Immunohistochemical (IHC) assessment of TMAs is the principal method for analyzing protein expression in large numbers of patient samples efficient with conservation of tissue. However, manual IHC assessment of TMAs remains a challenging and laborious task. With advances in image analysis, computer generated analyses of TMAs have the potential to lessen the burden of expert pathologist review. Computerized ER scoring relies on tumor localization.

Aim: The objective of this study was to compare the effectiveness of a locally developed automated invasive tumor location system with the skills of specialist breast pathologists.

Methods: In this study, tumor localization for estrogen receptor (ER) scoring was evaluated comparing computer- generated segmentation masks with those of two specialist breast pathologists. Automated tumor localization was achieved using a novel image analysis algorithm, which labeled compact groups of pixels called superpixels. Machine learning techniques were adopted to model color, shape and textural properties of superpixels in a rotation invariant manner, suitable for histopathology images. The resulting automatically and manually-obtained segmentation masks were used to obtain IHC scores for thirty-two ER stained invasive breast cancer TMA samples using FDA-approved IHC scoring software.

Results: Pixel-level comparisons showed lower agreement between automated and manual segmentation masks (κ = 0.84) than between pathologists' masks (κ = 0.91). However, this had little impact on computed IHC scores (Allred method; κ = 0.91, Quickscore method; κ = 0.92).

Conclusion: The automated system provides sufficiently consistent measurements for standardized IHC analysis of nuclear staining in TMAs from large clinical trials.

Citation Format: Jordan LB, Akbar S, Purdie CA, Thompson AM, McKenna SJ. Breast cancer estrogen receptor scoring in tissue microarrays: Specialist breast pathologist versus automation. [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 P5-07-15.

Origins of tropospheric ozone interannual variation (IAV) over Réunion: A model investigation

Observations from long-term ozonesonde measurements show robust variations and trends in the evolution of ozone in the middle and upper troposphere over Réunion Island (21.1°S, 55.5°E) in June-August. Here we examine possible causes of the observed ozone variation at Réunion Island using hindcast simulations by the stratosphere-troposphere Global Modeling Initiative chemical transport model (GMI-CTM) for 1992-2014, driven by assimilated Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields. Réunion Island is at the edge of the subtropical jet, a region of strong stratospheric-tropospheric exchange (STE). Our analysis implies that the large interannual variation (IAV) of upper tropospheric ozone over Réunion is driven by the large IAV of the stratospheric influence. The IAV of the large-scale, quasi-horizontal wind patterns also contributes to the IAV of ozone in the upper troposphere. Comparison to a simulation with constant emissions indicates that increasing emissions do not lead to the maximum trend in the middle and upper troposphere over Réunion during austral winter implied by the sonde data. The effects of increasing emission over southern Africa are limited to the lower troposphere near the surface in August - September.

A pervasive role for biomass burning in tropical high ozone/low water structures

Air parcels with mixing ratios of high O3 and low H2O (HOLW) are common features in the tropical western Pacific (TWP) mid-troposphere (300-700 hPa). Here, using data collected during aircraft sampling of the TWP in winter 2014, we find strong, positive correlations of O3 with multiple biomass burning tracers in these HOLW structures. Ozone levels in these structures are about a factor of three larger than background. Models, satellite data and aircraft observations are used to show fires in tropical Africa and Southeast Asia are the dominant source of high O3 and that low H2O results from large-scale descent within the tropical troposphere. Previous explanations that attribute HOLW structures to transport from the stratosphere or mid-latitude troposphere are inconsistent with our observations. This study suggest a larger role for biomass burning in the radiative forcing of climate in the remote TWP than is commonly appreciated.

Why do Models Overestimate Surface Ozone in the Southeastern United States?

Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NO_x ≡ NO + NO₂) and biogenic isoprene. Model estimates of surface ozone concentrations tend to be biased high in the region and this is of concern for designing effective emission control strategies to meet air quality standards. We use detailed chemical observations from the SEAC⁴RS aircraft campaign in August and September 2013, interpreted with the GEOS-Chem chemical transport model at 0.25°×0.3125° horizontal resolution, to better understand the factors controlling surface ozone in the Southeast US. We find that the National Emission Inventory (NEI) for NO_x from the US Environmental Protection Agency (EPA) is too high. This finding is based on SEAC⁴RS observations of NO_x and its oxidation products, surface network observations of nitrate wet deposition fluxes, and OMI satellite observations of tropospheric NO₂ columns. Our results indicate that NEI NO_x emissions from mobile and industrial sources must be reduced by 30-60%, dependent on the assumption of the contribution by soil NO_x emissions. Upper tropospheric NO₂ from lightning makes a large contribution to satellite observations of tropospheric NO₂ that must be accounted for when using these data to estimate surface NO_x emissions. We find that only half of isoprene oxidation proceeds by the high-NO_x pathway to produce ozone; this fraction is only moderately sensitive to changes in NO_x emissions because isoprene and NO_x emissions are spatially segregated. GEOS-Chem with reduced NO_x emissions provides an unbiased simulation of ozone observations from the aircraft, and reproduces the observed ozone production efficiency in the boundary layer as derived from a regression of ozone and NO_x oxidation products. However, the model is still biased high by 8±13 ppb relative to observed surface ozone in the Southeast US. Ozonesondes launched during midday hours show a 7 ppb ozone decrease from 1.5 km to the surface that GEOS-Chem does not capture. This bias may reflect a combination of excessive vertical mixing and net ozone production in the model boundary layer.

Magnetic resonance imaging texture analysis classification of primary breast cancer

OBJECTIVES

Patient-tailored treatments for breast cancer are based on histological and immunohistochemical (IHC) subtypes. Magnetic Resonance Imaging (MRI) texture analysis (TA) may be useful in non-invasive lesion subtype classification.

METHODS

Women with newly diagnosed primary breast cancer underwent pre-treatment dynamic contrast-enhanced breast MRI. TA was performed using co-occurrence matrix (COM) features, by creating a model on retrospective training data, then prospectively applying to a test set. Analyses were blinded to breast pathology. Subtype classifications were performed using a cross-validated k-nearest-neighbour (k = 3) technique, with accuracy relative to pathology assessed and receiver operator curve (AUROC) calculated. Mann-Whitney U and Kruskal-Wallis tests were used to assess raw entropy feature values.

RESULTS

Histological subtype classifications were similar across training (n = 148 cancers) and test sets (n = 73 lesions) using all COM features (training: 75%, AUROC = 0.816; test: 72.5%, AUROC = 0.823). Entropy features were significantly different between lobular and ductal cancers (p < 0.001; Mann-Whitney U). IHC classifications using COM features were also similar for training and test data (training: 57.2%, AUROC = 0.754; test: 57.0%, AUROC = 0.750). Hormone receptor positive and negative cancers demonstrated significantly different entropy features. Entropy features alone were unable to create a robust classification model.

CONCLUSION

Textural differences on contrast-enhanced MR images may reflect underlying lesion subtypes, which merits testing against treatment response.

KEY POINTS

• MR-derived entropy features, representing heterogeneity, provide important information on tissue composition. • Entropy features can differentiate between histological and immunohistochemical subtypes of breast cancer. • Differing entropy features between breast cancer subtypes implies differences in lesion heterogeneity. • Texture analysis of breast cancer potentially provides added information for decision making.

Effects of local meteorology and aerosols on ozone and nitrogen dioxide retrievals from OMI and pandora spectrometers in Maryland, USA during DISCOVER-AQ 2011

An analysis is presented for both ground- and satellite-based retrievals of total column ozone and nitrogen dioxide levels from the Washington, D.C., and Baltimore, Maryland, metropolitan area during the NASA-sponsored July 2011 campaign of Deriving Information on Surface COnditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ). Satellite retrievals of total column ozone and nitrogen dioxide from the Ozone Monitoring Instrument (OMI) on the Aura satellite are used, while Pandora spectrometers provide total column ozone and nitrogen dioxide amounts from the ground. We found that OMI and Pandora agree well (residuals within ±25 % for nitrogen dioxide, and ±4.5 % for ozone) for a majority of coincident observations during July 2011. Comparisons with surface nitrogen dioxide from a Teledyne API 200 EU NO_x Analyzer showed nitrogen dioxide diurnal variability that was consistent with measurements by Pandora. However, the wide OMI field of view, clouds, and aerosols affected retrievals on certain days, resulting in differences between Pandora and OMI of up to ±65 % for total column nitrogen dioxide, and ±23 % for total column ozone. As expected, significant cloud cover (cloud fraction >0.2) was the most important parameter affecting comparisons of ozone retrievals; however, small, passing cumulus clouds that do not coincide with a high (>0.2) cloud fraction, or low aerosol layers which cause significant backscatter near the ground affected the comparisons of total column nitrogen dioxide retrievals. Our results will impact post-processing satellite retrieval algorithms and quality control procedures.

Bay breeze influence on surface ozone at Edgewood, MD during July 2011

Surface ozone (O₃) was analyzed to investigate the role of the bay breeze on air quality at two locations in Edgewood, Maryland (lat: 39.4°, lon: -76.3°) for the month of July 2011. Measurements were taken as part of the first year of NASA's "Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality" (DISCOVER-AQ) Earth Venture campaign and as part of NASA's Geostationary for Coastal and Air Pollution Events Chesapeake Bay Oceanographic campaign with DISCOVER-AQ (Geo-CAPE CBODAQ). Geo-CAPE CBODAQ complements DISCOVER-AQ by providing ship-based observations over the Chesapeake Bay. A major goal of DISCOVER-AQ is determining the relative roles of sources, photochemistry and local meteorology during air quality events in the Mid-Atlantic region of the U.S. Surface characteristics, transport and vertical structures of O₃ during bay breezes were identified using in-situ surface, balloon and aircraft data, along with remote sensing equipment. Localized late day peaks in O₃ were observed during bay breeze days, maximizing an average of 3 h later compared to days without bay breezes. Of the 10 days of July 2011 that violated the U.S. Environmental Protection Agency (EPA) 8 h O₃ standard of 75 parts per billion by volume (ppbv) at Edgewood, eight exhibited evidence of a bay breeze circulation. The results indicate that while bay breezes and the processes associated with them are not necessary to cause exceedances in this area, bay breezes exacerbate poor air quality that sustains into the late evening hours at Edgewood. The vertical and horizontal distributions of O₃ from the coastal Edgewood area to the bay also show large gradients that are often determined by boundary layer stability. Thus, developing air quality models that can sufficiently resolve these dynamics and associated chemistry, along with more consistent monitoring of O₃ and meteorology on and along the complex coastline of Chesapeake Bay must be a high priority.

Ozone correlations between mid-tropospheric partial columns and the near-surface at two mid-atlantic sites during the DISCOVER-AQ campaign in July 2011

The current network of ground-based monitors for ozone (O₃) is limited due to the spatial heterogeneity of O₃ at the surface. Satellite measurements can provide a solution to this limitation, but the lack of sensitivity of satellites to O₃ within the boundary layer causes large uncertainties in satellite retrievals at the near-surface. The vertical variability of O₃ was investigated using ozonesondes collected as part of NASA's Deriving Information on Surface Conditions from COlumn and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign during July 2011 in the Baltimore, MD/Washington D.C. metropolitan area. A subset of the ozonesonde measurements was corrected for a known bias from the electrochemical solution strength using new procedures based on laboratory and field tests. A significant correlation of O₃ over the two sites with ozonesonde measurements (Edgewood and Beltsville, MD) was observed between the mid-troposphere (7-10 km) and the near-surface (1-3 km). A linear regression model based on the partial column amounts of O₃ within these subregions was developed to calculate the near-surface O₃ using mid-tropospheric satellite measurements from the Tropospheric Emission Spectrometer (TES) onboard the Aura spacecraft. The uncertainties of the calculated near-surface O₃ using TES mid-tropospheric satellite retrievals and a linear regression model were less than 20 %, which is less than that of the observed variability of O₃ at the surface in this region. These results utilize a region of the troposphere to which existing satellites are more sensitive compared to the boundary layer and can provide information of O₃ at the near-surface using existing satellite infrastructure and algorithms.

Bay breeze climatology at two sites along the Chesapeake bay from 1986-2010: Implications for surface ozone

Hourly surface meteorological measurements were coupled with surface ozone (O₃) mixing ratio measurements at Hampton, Virginia and Baltimore, Maryland, two sites along the Chesapeake Bay in the Mid-Atlantic United States, to examine the behavior of surface O₃ during bay breeze events and quantify the impact of the bay breeze on local O₃ pollution. Analyses were performed for the months of May through September for the years 1986 to 2010. The years were split into three groups to account for increasingly stringent environmental regulations that reduced regional emissions of nitrogen oxides (NO_x): 1986-1994, 1995-2002, and 2003-2010. Each day in the 25-year record was marked either as a bay breeze day, a non-bay breeze day, or a rainy/cloudy day based on the meteorological data. Mean eight hour (8-h) averaged surface O₃ values during bay breeze events were 3 to 5 parts per billion by volume (ppbv) higher at Hampton and Baltimore than on non-bay breeze days in all year periods. Anomalies from mean surface O₃ were highest in the afternoon at both sites during bay breeze days in the 2003-2010 study period. In conjunction with an overall lowering of baseline O₃ after the 1995-2002 period, the percentage of total exceedances of the Environmental Protection Agency (EPA) 75 ppbv 8-h O₃ standard that occurred on bay breeze days increased at Hampton for 2003-2010, while remaining steady at Baltimore. These results suggest that bay breeze circulations are becoming more important to causing exceedance events at particular sites in the region, and support the hypothesis of Martins et al. (2012) that highly localized meteorology increasingly drives air quality events at Hampton.

Evaluation of NAQFC model performance in forecasting surface ozone during the 2011 DISCOVER-AQ campaign

The National Air Quality Forecast Capability (NAQFC) and an experimental version of the NAQFC (NAQFC-β) provided flight decision support during the July 2011 NASA DISCOVER-AQ field campaign around Baltimore, Maryland. Ozone forecasts from the NAQFC and NAQFC-β were compared to surface observations at six air quality monitoring stations in the DISCOVER-AQ domain. A bootstrap algorithm was used to test for significant bias and error in the forecasts from each model. Both models produce significant positively biased forecasts in the morning while generally becoming insignificantly biased in the afternoon during peak ozone hours. The NAQFC-β produces higher forecast bias, higher forecast error, and lower correlations than the NAQFC. Forecasts from the two models were also compared to each other to determine the spatial and temporal extent of significant differences in forecasted ozone using a bootstrap algorithm. The NAQFC-β tends to produce an average background ozone mixing ratio of at least 3.51 ppbv greater than the NAQFC throughout the domain at 95 % significance. The difference between the two models is significant during the overnight and early morning hours likely due to the way the Carbon Bond 5 mechanism in the NAQFC-β handles reactive nitrogen recycling and organic peroxide species. The value of information each model provides was tested using a static cost-loss ratio model. By standard measures of forecast skill, the NAQFC generally outperforms the NAQFC-β; however, the NAQFC-β provides greater value of information. This is because standard measures of forecast skill often hide the sensitivity of end users' needs to forecast error.

NEOCENT: a randomised feasibility and translational study comparing neoadjuvant endocrine therapy with chemotherapy in ER-rich postmenopausal primary breast cancer

Neoadjuvant endocrine therapy is an alternative to chemotherapy for women with oestrogen receptor (ER)-positive early breast cancer (BC). We aimed to assess feasibility of recruiting patients to a study comparing chemotherapy versus endocrine therapy in postmenopausal women with ER-rich primary BC, and response as well as translational endpoints were assessed. Patients requiring neoadjuvant therapy were randomised to chemotherapy: 6 × 3-weekly cycles FE₁₀₀C or endocrine therapy: letrozole 2.5 mg, daily for 18-23 weeks. Primary endpoints were recruitment feasibility and tissue collection. Secondary endpoints included clinical, radiological and pathological response rates, quality of life and translational endpoints. 63/80 patients approached were eligible, of those 44 (70, 95% CI 57-81) were randomised. 12 (54.5, 95% CI 32.2-75.6) chemotherapy patients showed radiological objective response compared with 13 (59.1, 95% CI 36.4-79.3) letrozole patients. Compared with baseline, mean Ki-67 levels fell in both groups at days 2-4 and at surgery [fold change: 0.24 (95% CI 0.12-0.51) and 0.24; (95% CI 0.15-0.37), respectively]. Plasma total cfDNA levels rose from baseline to week 8 [fold change: chemotherapy 2.10 (95% CI 1.47-3.00), letrozole 1.47(95% CI 0.98-2.20)], and were maintained at surgery in the chemotherapy group [chemotherapy 2.63; 95% CI 1.56-4.41), letrozole 0.95 (95% CI 0.71-1.26)]. An increase in plasma let-7a miRNA was seen at surgery for patients with objective radiological response to chemotherapy. Recruitment and tissue collection endpoints were met; however, a larger trial was deemed unfeasible due to slow accrual. Both regimens were equally efficacious. Dynamic changes were seen in Ki-67 and circulating biomarkers in both groups with increases in cfDNA and let-7a miRNA persisting until surgery for chemotherapy patients.

Microfluidics for single-cell genetic analysis

The ability to correlate single-cell genetic information to cellular phenotypes will provide the kind of detailed insight into human physiology and disease pathways that is not possible to infer from bulk cell analysis. Microfluidic technologies are attractive for single-cell manipulation due to precise handling and low risk of contamination. Additionally, microfluidic single-cell techniques can allow for high-throughput and detailed genetic analyses that increase accuracy and decrease reagent cost compared to bulk techniques. Incorporating these microfluidic platforms into research and clinical laboratory workflows can fill an unmet need in biology, delivering the highly accurate, highly informative data necessary to develop new therapies and monitor patient outcomes. In this perspective, we describe the current and potential future uses of microfluidics at all stages of single-cell genetic analysis, including cell enrichment and capture, single-cell compartmentalization and manipulation, and detection and analyses.