Abstract P5-20-17: Safety of continuing chemotherapy in overt left ventricular dysfunction using antibodies to human epidermal growth factor receptor-2: A retrospective study

Introduction: Trastuzumab is a monoclonal antibody that targets the human epidermal growth factor receptor (HER)-2 and significantly improves survival in HER-2 positive early stage breast cancer. However, trastuzumab is also known to cause cardiotoxicity. Guidelines recommend withholding or discontinuing trastuzumab if left ventricular ejection fraction (LVEF) falls ≥15% from baseline, or to <50%, but there is little evidence to support this strategy. Additionally, premature discontinuation of trastuzumab may lead to poorer cancer outcomes. Trastuzumab cardiotoxicity is frequently reversible, and the use of angiotensin converting enzyme-inhibitors (ACE-I) and beta blockers is highly effective at treating impaired LVEF in other patient populations. We therefore hypothesize that it is safe to continue trastuzumab in patients with asymptomatic or mildly symptomatic fall in LVEF, when concomitantly treated with ACE-I and beta blockers.

Methods: In this retrospective chart review, we identified 18 consecutive patients with stage 1-3 HER-2 positive breast cancer patients who had a decline in LVEF meeting the criteria above to withhold trastuzumab, and who were referred to our cardio-oncology service from the beginning of 2015 to March 2017. These patients were offered and consented to receive ongoing trastuzumab accompanied by ACE-I and/or beta blocker. Data on patient demographics, cancer therapies, clinical features, LVEF, and cardiac medications were extracted from medical charts.

Results: Among the 18 patients identified, all were women, 12 (67%) were estrogen receptor positive, and 7 progesterone receptor positive (39%). 11 (61%) of patients had a left-sided breast cancer, 6 (33%) had right-sided breast cancer, and 1 (5%) had an unspecified side breast cancer. 17 (94%) of patients had previously undergone radiation therapy, and 4 (22%) had experienced a recurrence. 16 patients had received a prior anthracycline regimen (10 sequentially, 6 concurrently). The patients were treated with one or a combination of the following medications: carvedilol (n=13), ramipril (n=12), bisoprolol (n=1), candesartan (n=2), rosuvastatin (n=2), atorvastatin (n=2). The patients were followed up for an average of 7 months after starting cardiac therapy. Table 1 summarizes the mean±SD LVEF values over the follow up time period. All patient except one (94%) completed trastuzumab treatment successfully. This patient with concomitant moderate-severe mitral regurgitation was hospitalized for pulmonary edema. Trastuzumab was discontinued and LVEF has subsequently returned to normal values.

Table 1: LVEF progression from baseline to end of follow-upMean±SD LVEF at baseline57.59±5.49%Mean±SD LVEF on referral to cardio-oncology clinic50.75±4.76%Mean±SD LVEF at end of follow-up56.35±3.50%

Conclusion: Treating cardiac dysfunction related to trastuzumab in a cardio-oncology clinic, using beta blockers and ACE-I may enable completion of trastuzumab therapy. Randomized trials are necessary before it can be widely recommended, however findings from our experience suggest this may be a promising new treatment strategy.

Citation Format: Bharaj UK, Leong D, Dhesy-Thind S, Ellis P, Mukherjee S, Bordeleau L, Phillips C, Brown M, Kumar Tyagi N. Safety of continuing chemotherapy in overt left ventricular dysfunction using antibodies to human epidermal growth factor receptor-2: A retrospective study [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 P5-20-17.

Abstract PD2-13: Benefits to breast screening beyond mortality reduction

Background

The value of population-based mammographic screening has been questioned by those who believe that the reduction in mortality from earlier diagnosis is outweighed by harms including overdiagnosis and overtreatment. Much of these commentaries assume that all Early-Stage Breast Cancer (ESBC) is treated the same way after diagnosis; with extensive therapies including surgery, radiotherapy and chemotherapy being standard.

Intensity of treatment received is rarely mentioned in the debate. We hypothesised that those diagnosed through a screening program (Active Screeners (AS)) would receive less extensive surgical treatment and less intense adjuvant therapies than those not recently screened (NRS). If demonstrated, these differences would form an important component of the debate over the role of mammographic screening.

Methods

Retrospective analysis of a consecutive cohort of female patients aged 50-69 and managed for ESBC (invasive or DCIS) during 2007-2013 within a large metropolitan Breast Service, diagnosed either via a population screening program (AS) or outside of the program (NRS). Data on patient characteristics, symptoms, mode of detection, tumour pathology, surgical intervention and adjuvant treatment recommendations were derived from prospectively collected Multi-Disciplinary Meeting (MDM) records. Patients with metastatic disease or prior treatment for breast cancer were excluded.

Results

791 cases were identified (569 with screen-detected cancer, 53 with interval cancers and 169 cancers diagnosed in women not recently screened). Invasive cancers in the AS group were much smaller than in the NRS group – mean 17mm versus 26mm. The AS group had lower grade invasive cancer – grade 1, 2 and 3 were 27%, 42%, 31% - compared with 10%, 39% and 52% in the NRS group. The AS group were more likely to have ER+ve cancers (88% vs 80%) and less likely to have nodal involvement (26% vs 48%). For invasive breast cancer, the NRS group were more than twice as likely to undergo mastectomy than cancers in the AS group (35% vs 16%). Axillary dissections were more common in the NRS than the AS group (43% vs 19%). Adjuvant chemotherapy was recommended more frequently for the NRS group compared to the AS group (65% vs 37%), as was post mastectomy radiotherapy (58% vs 39%). Endocrine therapy was less often recommended to the NRS group (86% versus 77%).

Conclusion

Women diagnosed with early stage breast cancer who are participating in a population based screening program are less likely to receive mastectomy and/or axillary dissection, less likely to receive adjuvant chemotherapy and less likely to receive post-mastectomy radiotherapy. These differences in treatment intensity should be considered in the debate surrounding mammographic screening.

Citation Format: Elder KJ, Nickson C, Cooke S, Machalek D, Rose A, Mou A, Collins JP, Park A, De Boer R, Phillips C, Pridmore V, Farrugia H, Mann GB. Benefits to breast screening beyond mortality reduction [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 PD2-13.

The Dorsal Attention Network Reflects Both Encoding Load and Top–down Control during Working Memory

The dorsal attention network is consistently involved in verbal and visual working memory (WM) tasks and has been associated with task-related, top–down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top–down strategic control. We examined the role of the dorsal attention network in encoding load and top–down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top–down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner.

Human brain patterns underlying vigilant attention: impact of sleep debt, circadian phase and attentional engagement

Sleepiness and cognitive function vary over the 24-h day due to circadian and sleep-wake-dependent mechanisms. However, the underlying cerebral hallmarks associated with these variations remain to be fully established. Using functional magnetic resonance imaging (fMRI), we investigated brain responses associated with circadian and homeostatic sleep-wake-driven dynamics of subjective sleepiness throughout day and night. Healthy volunteers regularly performed a psychomotor vigilance task (PVT) in the MR-scanner during a 40-h sleep deprivation (high sleep pressure) and a 40-h multiple nap protocol (low sleep pressure). When sleep deprived, arousal-promoting thalamic activation during optimal PVT performance paralleled the time course of subjective sleepiness with peaks at night and troughs on the subsequent day. Conversely, task-related cortical activation decreased when sleepiness increased as a consequence of higher sleep debt. Under low sleep pressure, we did not observe any significant temporal association between PVT-related brain activation and subjective sleepiness. Thus, a circadian modulation in brain correlates of vigilant attention was only detectable under high sleep pressure conditions. Our data indicate that circadian and sleep homeostatic processes impact on vigilant attention via specific mechanisms; mirrored in a decline of cortical resources under high sleep pressure, opposed by a subcortical “rescuing” at adverse circadian times.

Oral Sciences PhD Program Enrollment, Graduates, and Placement: 1994 to 2016

For decades, dental schools in the United States have endured a significant faculty shortage. Studies have determined that the top 2 sources of dental faculty are advanced education programs and private practice. Those who have completed both DDS and PhD training are considered prime candidates for dental faculty positions. However, there is no national database to track those trainees and no evidence to indicate that they entered academia upon graduation. The objective of this study was to assess outcomes of dental school-affiliated oral sciences PhD program enrollment, graduates, and placement between 1994 and 2016. Using the American Dental Association annual survey of advanced dental education programs not accredited by the Commission on Dental Accreditation and data obtained from 22 oral sciences PhD programs, we assessed student demographics, enrollment, graduation, and placement. Based on the data provided by program directors, the average new enrollment was 33, and graduation was 26 per year. A total of 605 graduated; 39 did not complete; and 168 were still in training. Among those 605 graduates, 211 were faculty in U.S. academic institutions, and 77 were faculty in foreign institutions. Given that vacant budgeted full-time faculty positions averaged 257 per year during this period, graduates from those oral sciences PhD programs who entered academia in the United States would have filled 9 (3.6%) vacant faculty positions per year. Therefore, PhD programs have consistently generated only a small pipeline of dental school faculty. Better mentoring to retain talent in academia is necessary. Stronger support and creative funding plans are essential to sustain the PhD program. Furthermore, the oral sciences PhD program database should be established and maintained by dental professional organizations to allow assessments of training models, trends of enrollment, graduation, and placement outcomes.

Embedding Anatomical or Functional Knowledge in Whole-Brain Multiple Kernel Learning Models

Pattern recognition models have been increasingly applied to neuroimaging data over the last two decades. These applications have ranged from cognitive neuroscience to clinical problems. A common limitation of these approaches is that they do not incorporate previous knowledge about the brain structure and function into the models. Previous knowledge can be embedded into pattern recognition models by imposing a grouping structure based on anatomically or functionally defined brain regions. In this work, we present a novel approach that uses group sparsity to model the whole brain multivariate pattern as a combination of regional patterns. More specifically, we use a sparse version of Multiple Kernel Learning (MKL) to simultaneously learn the contribution of each brain region, previously defined by an atlas, to the decision function. Our application of MKL provides two beneficial features: (1) it can lead to improved overall generalisation performance when the grouping structure imposed by the atlas is consistent with the data; (2) it can identify a subset of relevant brain regions for the predictive model. In order to investigate the effect of the grouping in the proposed MKL approach we compared the results of three different atlases using three different datasets. The method has been implemented in the new version of the open-source Pattern Recognition for Neuroimaging Toolbox (PRoNTo).

Secondary osteons scale allometrically in mammalian humerus and femur

Intra-cortical bone remodelling is a cell-driven process that replaces existing bone tissue with new bone tissue in the bone cortex, leaving behind histological features called secondary osteons. While the scaling of bone dimensions on a macroscopic scale is well known, less is known about how the spatial dimensions of secondary osteons vary in relation to the adult body size of the species. We measured the cross-sectional area of individual intact secondary osteons and their central Haversian canals in transverse sections from 40 stylopodal bones of 39 mammalian species (body mass 0.3-21 000 kg). Scaling analysis of our data shows that mean osteonal resorption area (negative allometry, exponent 0.23,R² 0.54,p<0.005) and Haversian canal area (negative allometry, exponent 0.31,R² 0.45,p<0.005) are significantly related to body mass, independent of phylogeny. This study is the most comprehensive of its kind to date, and allows us to describe overall trends in the scaling behaviour of secondary osteon dimensions, supporting the inference that the osteonal resorption area may be limited by the need to avoid fracture in smaller mammalian species, but the need to maintain osteocyte viability in larger mammalian species.

The effect of the A-frame on forelimb kinematics in experienced and inexperienced agility dogs

Limited research has evaluated the kinematics of agility dogs over different equipment despite the growing popularity of recreational and competitive agility. A-frames are associated with a higher risk of injury; these risks could be related to how dogs approach the equipment. We hypothesised that forelimb (FL) and spinal kinematics would differ throughout the different phases of negotiating the A-frame: incline, apex, decline, and between experienced and inexperienced agility dogs. Eight agility dogs of mixed breed and age, all trained on the A-frame participated in the study. Participants were divided into two groups: inexperienced dogs (ID: <4 years training; n=4) and experienced dogs (ED: >4years training; n=4), and undertook 3 runs over the A-frame. Reflective markers were placed on each dog’s carpus (Ca), radiohumeral (RH) and scapulohumerus (SH) joints, Atlas, C3 and L3. Video footage was transferred to Dartfish™ to enable FL joint angles to be calculated for the approach (last stride), incline (FL contact), apex (FL over), decline (FL touchdown and FL departure). The range of movement (ROM) for spinal markers was also calculated. Wilcoxon signed rank analyses, with Bonferroni correction applied (P<0.02), indicated if kinematics differed for ED and ID between the phases. Similar kinematic patterns were observed through all phases for C3 and L3, however a greater ROM was found for ED: C3 and ID: L3. For Atlas, ED stayed in flexion for all phases whilst ID movement varied: approach-incline extension, incline-apex: flexion, apex to decline extension followed by flexion. No significant differences in FL joint angles existed (P>0.02). No significant differences in kinematic measures were seen between ED and ID dogs in any phase of the A-frame. ED demonstrate consistent movement patterns; ID vary their head and neck position more, and exaggerate their apex jump. Rounding the A-frame apex could encourage a less-extreme technique in ID.

Impact of periodontal intervention on local inflammation, periodontitis, and HIV outcomes

OBJECTIVE

The aim of this study was to determine active periodontal disease status in HIV and to determine the impact of periodontal disease resolution on HIV status.

METHODS

In this longitudinal cohort study, 73 HIV-positive subjects received comprehensive dental care. AAP, CDC/AAP, and BGI case definitions determined periodontal classification. Likelihood and frequency of moderate/severe periodontal disease were assessed based on demographic variables. The influence of periodontal intervention was assessed at baseline, 12, and 24 months. IL-6 was measured in a subset of subjects.

RESULTS

Of the periodontal classifications, BGI demonstrated the highest percentage category improvement with the intervention (>50%). Moderate/severe periodontitis was positively associated with HIV regardless of race, smoking status, gender, income level, and age, and was associated with increased IL-6. At baseline, the majority of subjects had severe periodontal disease regardless of ART status. Subjects with suppressed viral load at baseline demonstrated a significant improvement in BGI classification (P = 0.026), increased CD4 counts (P = 0.027), and decreased IL-6 levels (P = 0.03).

CONCLUSIONS

Periodontal inflammation was prevalent regardless of ART status. In virologically suppressed subjects, the intervention decreased periodontitis with a concomitant IL-6 decrease and CD4 increase. These findings suggest a relationship between periodontal inflammation, oral microbial translocation, and HIV status.

Cognitive brain responses during circadian wake-promotion: evidence for sleep-pressure-dependent hypothalamic activations

The two-process model of sleep-wake regulation posits that sleep-wake-dependent homeostatic processes interact with the circadian timing system to affect human behavior. The circadian timing system is fundamental to maintaining stable cognitive performance, as it counteracts growing homeostatic sleep pressure during daytime. Using magnetic resonance imaging, we explored brain responses underlying working memory performance during the time of maximal circadian wake-promotion under varying sleep pressure conditions. Circadian wake-promoting strength was derived from the ability to sleep during an evening nap. Hypothalamic BOLD activity was positively linked to circadian wake-promoting strength under normal, but not under disproportionally high or low sleep pressure levels. Furthermore, higher hypothalamic activity under normal sleep pressure levels predicted better performance under sleep loss. Our results reappraise the two-process model by revealing a homeostatic-dose-dependent association between circadian wake-promotion and cognition-related hypothalamic activity.