AXL receptor is required for Zika virus strain MR-766 infection in human glioblastoma cell lines

Recent reports have shown that Zika virus (ZIKV) has oncolytic potential against human glioblastoma (GBM); however, the mechanisms underlying its tropism and cell entry are not completely understood. The receptor tyrosine kinase AXL has been identified as an entry receptor for ZIKV in a cell-type-specific manner. Interestingly, AXL is frequently overexpressed in GBM patients. Using commercially available GBM cell lines, we first show that cells expressing AXL are permissive for ZIKV infection, while cells that do not express AXL are not. Furthermore, inhibition of AXL kinase using R428 and antibody blockade of AXL receptor strongly attenuated virus entry in GBM cell lines. Additionally, CRISPR knockout of the AXL gene in GBM cell lines completely abolished ZIKV infection, significantly inhibited viral replication, and significantly reduced apoptosis compared with parental lines. Lastly, introduction of AXL receptor into non-expressing cell lines renders the cells susceptible to ZIKV infection. Together, these findings demonstrate that ZIKV entry into GBM cells in vitro is mediated by the AXL receptor and that following cell entry, productive infection is cytotoxic. Thus, ZIKV is a potential oncolytic virus for GBM.

COVID-19 and Historic Influenza Vaccinations in the United States: A Comparative Analysis

The COVID-19 vaccination effort is a monumental global challenge. Recognizing and addressing the causes of vaccine hesitancy will improve vaccine uptake. The primary objective of this study was to compare the COVID-19 vaccination rates in US counties to historical vaccination rates for influenza in persons aged 65 and older. The secondary objective was to identify county-level demographic, socioeconomic, and political factors that influence vaccination rates. County level data were obtained from publicly available databases for comparison and to create predictive models. Overall, in US counties the COVID-19 vaccination rate exceeded influenza vaccination rates amongst those aged 65 or older (69.4.0% vs. 44%, p < 0.0001). 2690 (83.4%) of 3224 counties had vaccinated 50% or more of their 65 and older residents in the first seven months of the COVID-19 vaccination roll out. There were 467 (14.5%) of 3223 counties in which the influenza vaccination rate exceeded the COVID-19 vaccination rate. Most of these counties were in the Southern region, were considered politically "red" and had a significantly higher non-Hispanic Black resident population (14.4% vs. 8.2%, p < 0.0001). Interventions intended to improve uptake should account for nuances in vaccine access, confidence, and consider factual social media messaging, especially in vulnerable counties.

Race, Ethnicity, Neighborhood Characteristics, and In-Hospital Coronavirus Disease-2019 Mortality

BACKGROUND

Despite many studies reporting disparities in coronavirus disease-2019 (COVID-19) incidence and outcomes in Black and Hispanic/Latino populations, mechanisms are not fully understood to inform mitigation strategies.

OBJECTIVE

The aim was to test whether neighborhood factors beyond individual patient-level factors are associated with in-hospital mortality from COVID-19. We hypothesized that the Area Deprivation Index (ADI), a neighborhood census-block-level composite measure, was associated with COVID-19 mortality independently of race, ethnicity, and other patient factors.

RESEARCH DESIGN

Multicenter retrospective cohort study examining COVID-19 in-hospital mortality.

SUBJECTS

Inclusion required hospitalization with positive SARS-CoV-2 test or COVID-19 diagnosis at three large Midwestern academic centers.

MEASURES

The primary study outcome was COVID-19 in-hospital mortality. Patient-level predictors included age, sex, race, insurance, body mass index, comorbidities, and ventilation. Neighborhoods were examined through the national ADI neighborhood deprivation rank comparing in-hospital mortality across ADI quintiles. Analyses used multivariable logistic regression with fixed site effects.

RESULTS

Among 5999 COVID-19 patients median age was 61 (interquartile range: 44-73), 48% were male, 30% Black, and 10.8% died. Among patients who died, 32% lived in the most disadvantaged quintile while 11% lived in the least disadvantaged quintile; 52% of Black, 24% of Hispanic/Latino, and 8.5% of White patients lived in the most disadvantaged neighborhoods.Living in the most disadvantaged neighborhood quintile predicted higher mortality (adjusted odds ratio: 1.74; 95% confidence interval: 1.13-2.67) independent of race. Age, male sex, Medicare coverage, and ventilation also predicted mortality.

CONCLUSIONS

Neighborhood disadvantage independently predicted in-hospital COVID-19 mortality. Findings support calls to consider neighborhood measures for vaccine distribution and policies to mitigate disparities.

The Role of 3D Tractography in Skull Base Surgery: Technological Advances, Feasibility, and Early Clinical Assessment with Anterior Skull Base Meningiomas

Objective  The aim of this study is to determine feasibility of incorporating three-dimensional (3D) tractography into routine skull base surgery planning and analyze our early clinical experience in a subset of anterior cranial base meningiomas (ACM). Methods  Ninety-nine skull base endonasal and transcranial procedures were planned in 94 patients and retrospectively reviewed with a further analysis of the ACM subset. Main Outcome Measures  (1) Automated generation of 3D tractography; (2) co-registration 3D tractography with computed tomography (CT), CT angiography (CTA), and magnetic resonance imaging (MRI); and (3) demonstration of real-time manipulation of 3D tractography intraoperatively. ACM subset: (1) pre- and postoperative cranial nerve function, (2) qualitative assessment of white matter tract preservation, and (3) frontal lobe fluid-attenuated inversion recovery (FLAIR) signal abnormality. Results  Automated 3D tractography, with MRI, CT, and CTA overlay, was produced in all cases and was available intraoperatively. ACM subset : 8 (44%) procedures were performed via a ventral endoscopic endonasal approach (EEA) corridor and 12 (56%) via a dorsal anteromedial (DAM) transcranial corridor. Four cases (olfactory groove meningiomas) were managed with a combined, staged approach using ventral EEA and dorsal transcranial corridors. Average tumor volume reduction was 90.3 ± 15.0. Average FLAIR signal change was -30.9% ± 58.6. 11/12 (92%) patients (DAM subgroup) demonstrated preservation of, or improvement in, inferior fronto-occipital fasciculus volume. Functional cranial nerve recovery was 89% (all cases). Conclusion  It is feasible to incorporate 3D tractography into the skull base surgical armamentarium. The utility of this tool in improving outcomes will require further study.

White Matter Governed Superior Frontal Sulcus Surgical Paradigm: A Radioanatomic Microsurgical Study-Part II

BACKGROUND

Kocher's point (KP) and its variations have provided standard access to the frontal horn (FH) for over a century. Anatomic understanding of white matter tracts (WMTs) has evolved, now positioning us to better inform the optimal FH trajectory.

OBJECTIVE

To (1) undertake a literature review analyzing entry points (EPs) to the FH; (2) introduce a purpose-built WMT-founded superior frontal sulcus parafascicular (SFSP)-EP also referred to as the Kassam-Monroy entry point (KM-EP); and (3) compare KM-EP with KP and variants with respect to WMTs.

METHODS

(1) Literature review (PubMed database, 1892-2018): (a) stratification based on the corridor: i. ventricular catheter; ii. through-channel endoscopic; or iii. portal; (b) substratification based on intent: i. preoperatively planned or ii. intraoperative (postdural opening) for urgent ventricular drainage. (2) Anatomic comparisons of KM-EP, KP, and variants via (a) cadaveric dissections and (b) magnetic resonance-diffusion tensor imaging computational 3D modeling.

RESULTS

A total of 31 studies met inclusion criteria: (a) 9 utilized KP coordinate (1 cm anterior to the coronal suture (y-axis) and 3 cm lateral of the midline (x-axis) approximated by the midpupillary line) and 22 EPs represented variations. All 31 traversed critical subcortical WMTs, specifically the frontal aslant tract, superior longitudinal fasciculus II, and inferior fronto-occipital fasciculus, whereas KM-EP (x = 2.3, y = 3.5) spares these WMTs.

CONCLUSION

KP (x = 3, y = 1) conceived over a century ago, prior to awareness of WMTs, as well as its variants, anatomically place critical WMTs at risk. The KM-EP (x = 2.3, y = 3.5) is purpose built and founded on WMTs, representing anatomically safe access to the FH. Correlative clinical safety, which will be directly proportional to the size of the corridor, is yet to be established in prospective studies.

The Evolution of Cerebral Language Localization: Historical Analysis and Current Trends

Language localization has been an evolving concept over the past 150 years, with the emergence of several important yet conflicting ideologies. The classical theory, starting from the phrenologic work of Gall to the identification of specific regions of language function by Broca, Wernicke, and others, proposed that discrete subcomponents of language were organized into separate anatomic structural regions. The holism theory was postulated in an attempt to disclose that language function was instead attributed to a larger region of the cortex, in which cerebral regions may have the capability of assuming the function of damaged areas. However, this theory was largely abandoned in favor of discrete structural localizationist viewpoints. The subsequent cortical stimulatory work of Penfield led to the development of maps of localization, assigning an eloquent designation to specific regions. The expanding knowledge of cortical and subcortical anatomy allowed for the development of anatomically and functionally integrative language models. In particular, the dual stream model revisited the concept of regional interconnectivity and expanded the concept of eloquence. Advancements in cortical-subcortical stimulation, neurophysiologic monitoring, magnetic resonance diffusion tensor imaging/functional magnetic resonance imaging, awake neurosurgical technique, and knowledge gained by white matter tract anatomy and the Human Connectome Project, shed new light on the dynamic interconnectivity of the cerebrum. New studies are progressively opening doors to this paradigm, showing the dynamic and interdependent nature of language function. In this review, the evolution of language toward the evolving paradigm of dynamic language function and interconnectivity and its impact on shaping the neurosurgical paradigm are outlined.

White Matter-Governed Superior Frontal Sulcus Surgical Paradigm: A Radioanatomic Microsurgical Study—Part I

BACKGROUND

Frontal subcortical and intraventricular pathologies are traditionally accessed via transcortical or interhemispheric-transcallosal corridors.

OBJECTIVE

To describe the microsurgical subcortical anatomy of the superior frontal sulcus (SFS) corridor.

METHODS

Cadaveric dissections were undertaken and correlated with magnetic resonance imaging/diffusion-tensor imaging-Tractography. Surgical cases demonstrated clinical applicability.

RESULTS

SFS was divided into the following divisions: proximal, precentral sulcus to coronal suture; middle, 3-cm anterior to coronal suture; and distal, middle division to the orbital crest. Anatomy was organized as layered circumferential rings projecting radially towards the ventricles: (1) outer ring: at the level of the SFS, the following lengths were measured: (A) precentral sulcus to coronal suture = 2.29 cm, (B) frontal bone projection of superior sagittal sinus (SSS) to SFS = 2.37 cm, (C) superior temporal line to SFS = 3.0 cm, and (D) orbital crest to distal part of SFS = 2.32 cm; and (2) inner ring: (a) medial to SFS, U-fibers, frontal aslant tract (FAT), superior longitudinal fasciculus I (SLF-I), and cingulum bundle, (b) lateral to SFS, U-fibers, (SLF-II), claustrocortical fibers (CCF), and inferior fronto-occipital fasciculus, and (c) intervening fibers, FAT, corona radiata, and CCF. The preferred SFS parafascicular entry point (SFSP-EP) also referred to as the Kassam-Monroy entry point (KM-EP) bisects the distance between the midpupillary line and the SSS and has the following coordinates: x = 2.3 cm (lateral to SSS), y ≥ 3.5 cm (anterior to CS), and z = parallel corona radiata and anterior limb of the internal capsule.

CONCLUSION

SFS corridor can be divided into lateral, medial, and intervening white matter tract segments. Based on morphometric assessment, the optimal SFSP-EP is y ≥ 3.5 cm, x = 2.3 cm, and z = parallel to corona radiata and anterior limb of the internal capsule.

Abstract P6-03-22: MUC1 oncoprotein confers trastuzumab resistance in HER2-positive breast cancer cells by maintaining cancer stem cell phenotype

Background: Although trastuzumab has greatly improved the outcome of HER2-positive breast cancer, the emergence of resistance hampers its clinical benefits. Trastuzumab resistance is a multi-factorial consequence predominantly due to the presence of cancer stem-like cells (CSCs). Interestingly, upregulation of the MUC1 gene has been reported to be associated with CSC growth, but its function in regulating CSC proliferation has not been studied in the trastuzumab-resistant (TrR) breast cancer cohort.

Purpose: To evaluate the function of MUC1 in regulating cancer stem cell phenotype in TrR HER2-positive breast cancer cohort

Methods

20,000 cells of each HER2-positive cell line (BT474R, T47D, HCC1954) were plated in ultralow attachment dishes and cultured in complete Mammocult Media for two weeks. Bright-field images were acquired. For CD44/CD24 staining, cells were incubated with Cy7-conjugated anti-CD44 and CF594-conujugated anti-CD24 per the previously described protocol. Cy7- and CF594-conjugated anti-mouse IgG were used as negative controls. For cell cycle analysis, cells were harvested and fixed with 70% cold ethanol for 24 H, followed by incubation with propidium iodide (PI, 50 μg/ml) and RNase (50 μg/ml) for 30 min, and analyzed by flow cytometry using Flowjo software. To silence MUC1 expression, 1 × 106 cells were transfected using the Neon electroporation system with 5 ng siMUC1 or 5 ng control siRNA vectors. The cells were electroporated for 30 ms at 1100 volts with two pulses. The cells were plated in 6-well plates with the appropriate media, incubated at 37°C for 48 hours and processed for further experiments.

Results: Our results show that BT474R, the TrR cell line, forms more mammospheres and has a greater inherent CD44high/CD24low CSC population than BT474, the trastuzumab-sensitive (TrS) cell line, and that MUC1 is significantly upregulated in TrR compare to TrS HER2-positive breast cancer cells. We further demonstrate the significant inhibition of the CSC population upon silencing MUC1 expression by performing both mammosphere formation assay and CD44high/CD24low phenotype characterization and that this regulation is independent of cell cycle arrest or HER2 expression levels.

Conclusion: MUC1 oncoprotein confers trastuzumab resistance in HER2-Positive breast cancer cells by maintaining cancer stem cell phenotype, indicating that it could be a potential predictive and targetable biomarker to overcome trastuzumab resistance in HER2-Positive breast cancer patients.

Citation Format: Jun Yin, Andrea Sand, Mitchell Piacsek, Chaoyang Sun, Logan S. Friedrich, Richard A. Rovin, Judy A. Tjoe. MUC1 oncoprotein confers trastuzumab resistance in HER2-positive breast cancer cells by maintaining cancer stem cell phenotype [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-03-22.

A Feasibility Study of Lavender Aromatherapy in an Awake Craniotomy Environment

PURPOSE

Integrative medicine interventions are needed for awake craniotomies, as many patients experience anxiety. Lavender aromatherapy significantly reduces anxiety or pain in a variety of surgical procedures. This feasibility study used lavender aromatherapy during awake craniotomies to determine the number of patients who would consent and complete the study, the technicality of lavender aromatherapy use, and acceptance by operating room (OR) staff.

METHODS

We approached 40 consecutive patients (≥18 years old). Exclusion criteria were pulmonary issues or sensitivity to lavender. Outcome measures in consented patients were enrollment and completion rates, anxiety and pain as measured by the Visual Analog Scale for Anxiety (VAS-A) and Visual Analog Scale for Pain (VAS-P), and satisfaction with pain control using the Patient Opinion of Pain Management (POPM) survey.

RESULTS

Of the 40 patients approached, 4 declined participation or had their surgery cancelled. Of the remaining 36, 4 required increased sedation during surgery and 1 was unable to detect lavender. Thus, 31 patients (77.5%) completed the study. VAS-A and VAS-P scores trended lower after lavender inhalation, but the difference did not reach statistical significance. There was a slight increase in VAS-P score at the OR1 time point. Expectancy for reduction in both anxiety and pain were not significantly different. Improvement in anxiety also was not different, while improvement in pain trended lower (P=0.025). POPM results indicated the majority of patients were either "satisfied" or "very satisfied" with pain management.

CONCLUSIONS

This study demonstrated 77.5% completion and the ability to integrate lavender aromatherapy into the OR. Thus, we plan to conduct a randomized clinical trial to assess efficacy of lavender aromatherapy.

The Surgical White Matter Chassis: A Practical 3-Dimensional Atlas for Planning Subcortical Surgical Trajectories

BACKGROUND

The imperative role of white matter preservation in improving surgical functional outcomes is now recognized. Understanding the fundamental white matter framework is essential for translating the anatomic and functional literature into practical strategies for surgical planning and neuronavigation.

OBJECTIVE

To present a 3-dimensional (3-D) atlas of the structural and functional scaffolding of human white matter-ie, a "Surgical White Matter Chassis (SWMC)"-that can be used as an organizational tool in designing precise and individualized trajectory-based neurosurgical corridors.

METHODS

Preoperative diffusion tensor imaging magnetic resonance images were obtained prior to each of our last 100 awake subcortical resections, using a clinically available 3.0 Tesla system. Tractography was generated using a semiautomated deterministic global seeding algorithm. Tract data were conceptualized as a 3-D modular chassis based on the 3 major fiber types, organized along median and paramedian planes, with special attention to limbic and neocortical association tracts and their interconnections.

RESULTS

We discuss practical implementation of the SWMC concept, and highlight its use in planning select illustrative cases. Emphasis has been given to developing practical understanding of the arcuate fasciculus, uncinate fasciculus, and vertical rami of the superior longitudinal fasciculus, which are often-neglected fibers in surgical planning.

CONCLUSION

A working knowledge of white matter anatomy, as embodied in the SWMC, is of paramount importance to the planning of parafascicular surgical trajectories, and can serve as a basis for developing reliable safe corridors, or modules, toward the goal of "zero-footprint" transsulcal access to the subcortical space.

An Anatomically-Based Endoscopic Endonasal Model to Navigate the Anterior Ventral Skull Base

BACKGROUND

Endoscopic endonasal approaches to access the sellar and parasellar regions are challenging in the face of anatomical variations or pathologic conditions. We propose an anatomically-based model including the orbitosellar line (OSL), critical oblique foramen line (COFL), and paramedial anterior line (PAL) facilitating safe, superficial-to-deep dissection triangulating upon the medial opticocarotid recess.

METHODS

Five cadaveric heads were dissected to systematically expose the OSL, COFL, and PAL, illustrated with image guidance. Application of the coordinate system and a 6-step dissection sequence is described.

RESULTS

The coordinate system consists of 1) the OSL, connecting a) the anterior orbital point, junction of the anterior buttress of the middle turbinate with the agger nasi region, located 34.3 ± 0.9 mm above the intersection of the vertical plane of the lacrimal crest, and the orthogonal plane of the maxillo-ethmoidal suture; b) the posterior orbital point, junction of the optic canal with the lamina papyracea, located 4 ± 0.7 mm below the posterior ethmoidal artery; and c) the medial opticocarotid recess; 2) COFL (15 ± 2.8 mm), connecting the palatovaginal canal, vidian canal, and foramen rotundum; and 3) PAL (39 ± 0.06 mm), connecting the vidian canal with the posterior ethmoidal artery.

CONCLUSIONS

OSL, COFL, and PAL form an anatomically-based model for the systematic exposure when accessing the parasellar and sellar regions. Preliminary anatomical data suggest that this model may be of value when normal anatomy is distorted by pathology or anatomic variations.

Abstract 168: Transglutaminase 2 (TGM2) overexpression contributes to triple-negative breast cancer metastasis through AFAP1-dependent pathway

Triple-Negative Breast Cancer (TNBC) is a type of breast cancer with absence of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). It represents 10-20% of all breast cancer cases, and is associated with frequent relapse and poor prognosis due to the lack of targeted therapy. Amongst all TNBC, metastatic TNBC is associated with the worse prognosis and has the fewest therapeutic options. Therefore, identifying molecular drivers for TNBC metastasis and developing potential targeted therapies will be highly beneficial for patients with metastatic TNBC.

We classified 8 TNBC cell lines into two groups, more invasive (n = 3) vs. less invasive (n = 5), by assessing their abilities to both invade through 3D Matrigel and migrate distantly, characterized through in vitro cell invasion and migration assays, respectively. We compared the two groups using transcriptome profiles from Cancer Cell Line Encyclopedia (CCLE) and found that transglutaminase 2 (TGM2) was significantly upregulated in more invasive cell lines (fold change = 4.6, p &lt; 0.001). Overexpression of TGM2 at both RNA and protein levels was confirmed experimentally in more invasive TNBC cells. These findings indicated that TGM2 might play a role in TNBC metastasis, but its functionality in invasiveness has not been evaluated by previous studies. In our study, suppressing TGM2 expression either by TGM2 inhibitor, cystamine dihydrochloride (CD), or by silencing TGM2 (siRNA) was found to significantly reduce the amount of invaded cells and inhibit cell migration, suggesting that TGM2 contributes to both cell invasion and cell migration in TNBC.

Our analysis also showed a significant correlation (r = 0.94, p = 0.001) between expression levels of TGM2 and actin filament-associated protein 1 (AFAP-1). AFAP1, which regulates actin cytoskeleton integrity and was found to contribute to tumorigenic growth by regulating focal contacts in other cancer types, was suppressed when TGM2 expression was downregulated, suggesting that TGM2 may potentiate cell metastasis through upregulation of AFAP-1 expression in TNBC. We also observed co-localization of AFAP-1 and actin filaments and that downregulation of TGM2 dramatically reduced actin filament assembly.

These observations identify a novel role of TGM2 in promoting TNBC cell metastasis and a new machinery of TGM2 in regulating microfilaments through AFAP-1. To conclude, TGM2 could act as a powerful biomarker and a molecular target circumventing TNBC metastasis. (Judy A. Tjoe and Jun Yin are considered to be co-corresponding authors for this study)

Citation Format: Mitchell Piacsek, Andrea Sand, Richard A. Rovin, Dmitry Bosenko, Santhi D. Konduri, Judy A. Tjoe, Jun Yin. Transglutaminase 2 (TGM2) overexpression contributes to triple-negative breast cancer metastasis through AFAP1-dependent pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 168.

Abstract 3052: MGMT inhibition is associated with MAPK pathway inhibition and enhances Raf, MEK, ERK inhibitors and restores meaningful Temozolomide activity in melanoma

Braf and MEK inhibition leads to limited survival gains in melanoma. In this research we show that, in vitro, MGMT controls all MAPK pathway effectors. We show that triple lock - upstream and downstream, along the MAPK pathway - effectively restores durable Braf and MEK inhibitor activity and significantly sensitizes melanoma to Temozolomide. The advantage of a multiple lock approach on the MAPK pathway is substantiated by the lack of signaling cross talk. We briefly discuss how this simple MGMT based regulatory paradigm could be immediately exploited in the care of melanoma patients. We also show how this strategy was exploited in two, surviving, metastatic (to include CNS disease) melanoma patients who had failed Braf and MEK inhibition (2 and 5 years ago) who now show stable or negligible residual disease burden while continuing on an intermittent, low treatment density, combination regimen

Citation Format: George C. Bobustuc, Amin B. Kassam, Dmitry Bosenko, Deborah L. Donohoe, Richard A. Rovin, Santhi D. Konduri. MGMT inhibition is associated with MAPK pathway inhibition and enhances Raf, MEK, ERK inhibitors and restores meaningful Temozolomide activity in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3052.

Abstract P1-08-28: Impact of surgery and time to surgery on breast cancer survival in the United States, 2004–2014 (N=2,211,245)

Background: Surgery is very common for patients diagnosed with breast cancer. Its impact on survival depends on diagnostic, patient, tumor-related, and other-treatment factors. Moreover, time to surgery from the date of diagnosis is also a critical factor affecting outcome.

Objective: In this study we investigated the impact of surgery on survival in breast cancer patients using two methods: (1) multivariate regression; and (2) propensity score matching. For the patients undergoing surgical intervention, we aimed to identify the optimum time from diagnosis to surgery.

Methods: The study population was taken from the National Cancer Database over the years 2004 through 2014. Of 2,211,245 patients, 99.1% were female, 0.9% male, 85% non-Hispanic white, 10.5% black, 0.7% Hispanic, and 14.5% other races. Mean age of the patient population was 60.0 ± 13.4 years (range: 18–90). The majority of the patients (92.9%) underwent a surgical procedure.

Results: Overall, the patients who did not undergo surgery were 6.7 times more likely to die within the study time period (95% confidence interval [CI]: 6.7–6.8, p&lt;0.001) than those who did. However, after adjusting for patients' demographics, tumor-related factors, cancer stages, and combination of other treatments, the risk for dying of patients without surgery was 2.3 times higher (hazard ratio [HR]: 2.3, 95% CI: 2.3–2.4, p&lt;0.001). In the propensity-matched cohort of 51,630 patients that was divided equally into two groups — those who underwent surgery and those who did not — the risk of mortality remained 2.4 times higher for patients without surgery (HR: 2.4, 95% CI: 2.3–2.4, p&lt;0.001). Regarding time to surgery from the date of diagnosis, patient survival was best for the patients whose time to surgery ranged from 31 to 60 days. The next best timeframe was 61 to 90 days, followed by 30 days or fewer, then 91 to 120 days, and finally 120 and more days (p&lt;0.001).

Conclusion: Using two different statistical methods, surgery is clearly an independent predictor of survival for patients with breast cancer. After matching for other factors, patients not having surgery were more than twice as likely to die as their surgical counterparts. Time to surgery from the date of diagonosis confirmed ealier findings that surgery is most benificial within 2–3 months from the date of diangosis. These findings can provide clinical guidance to clinicians and patients for planning treatment.

Citation Format: Singh M, Konduri SD, Bobustuc GC, Rovin RA, Kassam AB. Impact of surgery and time to surgery on breast cancer survival in the United States, 2004–2014 (N=2,211,245) [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 P1-08-28.

Awake Surgical Management of Third Ventricular Tumors: A Preliminary Safety, Feasibility, and Clinical Applications Study

BACKGROUND

Endoscopic and microneurosurgical approaches to third ventricular lesions are commonly performed under general anesthesia.

OBJECTIVE

To report our initial experience with awake transsulcal parafascicular corridor surgery (TPCS) of the third ventricle and its safety, feasibility, and limitations.

METHODS

A total of 12 cases are reviewed: 6 colloid cysts, 2 central neurocytomas, 1 papillary craniopharyngioma, 1 basal ganglia glioblastoma, 1 thalamic glioblastoma, and 1 ependymal cyst. Lesions were approached using TPCS through the superior frontal sulcus. Pre-, intra-, and postoperative neurocognitive (NC) testing were performed on all patients.

RESULTS

No cases required conversion to general anesthesia. Awake anesthesia changed intraoperative management in 4/12 cases with intraoperative cognitive changes that required port re-positioning; 3/4 recovered. Average length of stay (LOS) was 6.1 d ± 6.6. Excluding 3 outliers who had preoperative NC impairment, the average LOS was 2.5 d ± 1.2. Average operative time was 3.00 h ± 0.44. Average awake anesthesia time was 5.05 h ± 0.54. There were no mortalities.

CONCLUSION

This report demonstrated the feasibility and safety of awake third ventricular surgery, and was not limited by pathology, size, or vascularity. The most significant factor impacting LOS was preoperative NC deficit. The most significant risk factor predicting a permanent NC deficit was preoperative 2/3 domain impairment combined with radiologic evidence of invasion of limbic structures – defined as a “NC resilience/reserve” in our surgical algorithm. Larger efficacy studies will be required to demonstrate the validity of the algorithm and impact on long-term cognitive outcomes, as well as generalizability of awake TPCS for third ventricular surgery.

Abstract WP293: A Prospective Validation of Stroke Network of Wisconsin (snow) Scale to Predict Large Vessel Occlusion (lvo) and Comparison With Other Stroke Scales

Background: Prior retrospective analysis confirmed that the Stroke Network of Wisconsin (SNOW) scale was highly predictive of large vessel occlusion (LVO) in patients with Acute Ischemic Stroke (AIS). In this study, we prospectively validated the SNOW scale for the identification of LVO. We also compared its accuracy to other stroke scales retrospectively applied to the same dataset.

Methods: The SNOW scale consists of 3 exam elements: expressive aphasia/Speaking difficulty (S), neglect (N) and Ocular deviation (O). The scale is positive if any one of these items is present. We prospectively evaluated all acute ischemic stroke (AIS) patients who presented within 24 hours after onset at Aurora St. Luke’s Medical Center between July 2017-February 2018 and calculated the SNOW score. We retrospectively calculated Rapid Arterial Occlusion Evaluation (RACE), the Field Assessment Stroke Triage for Emergency Destination (FAST-ED), the Vision Aphasia and Neglect Scale (VAN), the Cincinnati Prehospital Stroke Severity (CPSS), the Los Angeles Motor Scale (LAMS), the Prehospital Acute Stroke Severity Scale (PASS) for all patients. The predictive performance of all scales and National Institute of Health Stroke Scale (NIHSS) cut offs ≥6 were determined and compared. LVO was defined by total occlusions involving the intracranial internal carotid artery, middle cerebral artery (M1), or basilar arteries

Results: Among 344 AIS patients, 283 (82%) had vascular imaging and were included in the analysis. LVO was detected in 43 (15%). Positive SNOW scale showed: sensitivity = 0.84, specificity = 0.63, positive predictive value = 0.29, negative predictive value= 0.96, and area under the curve =0.74. SNOW scale had comparable accuracy to predict LVO as other scales and NIHSS cut offs ≥6. If LVO includes M2, positive SNOW had sensitivity of 0.85, specificity of 0.70, positive predictive value of 0.49, negative predictive value of 0.93 and area under the curve of 0.77. SNOW had the highest sensitivity but lowest specificity among other scales.

Conclusion: The SNOW scale is a simple and accurate tool to help identify AIS due to LVO, and it compares favorably to the other scales evaluated. A prospective validation study of the SNOW scale in the prehospital setting is underway.

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Abstract TMP66: Redefining Stroke Transport Patterns Using the SNOW Scale for Large Vessel Obstruction

Background: The SNOW (Stroke Network of Wisconsin) scale was developed to identify patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). We previously validated the SNOW scale with two retrospective and one prospective datasets of AIS patients evaluated in the Emergency Department of Aurora Health Care System hospitals. In all three studies, the SNOW scale showed a high sensitivity and accuracy and compared favorably to other stroke scales. Based on this, Milwaukee County EMS (MCEMS) implemented a new protocol incorporating the SNOW scale to prehospital triage of AIS patients: a patient with presumed AIS with a positive SNOW score, indicating LVO, paramedics are instructed to bypass the closest stroke hospital in favor of a thrombectomy capable hospital if no more than 15 minutes is added to the transport time. This is the first report of interim analysis of the data.

Methods: To be SNOW positive, a patient must exhibit at least one of the following findings: gaze deviation, expressive aphasia, or neglect. We prospectively reviewed a cohort of all suspected stroke patients MCEMS transported to the three thrombectomy capable hospitals in Milwaukee, WI, between March 1 2018 and December 31 2018. LVO was confirmed by vascular imaging and included occlusions of the intracranial internal carotid artery, middle cerebral artery (M1 and M2), anterior cerebral artery (A1 and A2), or the basilar arteries.

Results: In the first four month analysis, 108 suspected stroke transports arrived to Aurora St. Luke’s Medical Center. Of these 108, 21 (19.44%) were confirmed LVO stroke patients. The MCEMS SNOW scoring correctly identified 16 cases of LVO with a sensitivity of 76.19%, specificity of 39.98%, and accuracy (area under the receiving operating characteristics curve) of 0.5764. Aurora St. Luke’s Stroke Responders SNOW scoring correctly identified 20 LVO cases with a sensitivity of 95.24%, specificity of 58.62%, and accuracy of 0.7693. Between the EMS and Hospital SNOW scoring, all confirmed LVO patients were identified.

Conclusion: Upon analysis of interim data, the SNOW scale shows a high sensitivity and accuracy to predict LVO. Differences in EMS and Hospital scoring may be due to experience with administering the scale and the change in exam over time.

Olfactory groove and tuberculum sellae meningioma resection by endoscopic endonasal approach versus transcranial approach: A systematic review and meta-analysis of comparative studies

Intracranial meningiomas such as olfactory groove meningioma (OGM) and tuberculum sellae meningioma (TSM) arising at the anterior skull base are amenable to surgical resection. Traditionally, this has been achieved by transcranial approaches (TCAs), however, there has been an evolution in an endoscopic endonasal approach (EEA) within recent years. The aim of this systematic review and meta-analysis was to determine if the EEA was superior to the TCA in managing these anterior skull base meningioma based on comparative studies only, and highlight the limitations of the current literature. Searches of seven electronic databases from inception to April 2018 were conducted following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. There were 1479 articles identified for screening. Data were extracted and analyzed using meta-analysis of proportions. A total of 10 comparative studies satisfied criteria for inclusions. Resection by the EEA resulted in significantly less likelihood of worse vision (OR, 0.318; p = 0.039) when compared to TCA in OGM. However, EEA resulted also in significantly greater likelihoods of olfactory loss in OGM (OR, 4.511; p = 0.038) and TSM (OR, 3.075; p = 0.017), and CSF leak (OR, 3.854; p = 0.013) in TSM. In terms of surgical and prognosis outcomes, there was no statistically significant trend in favor of either approach in OGM or TSM. The EEA appears to confer a different postoperative complication profile when compared to the TCA in resecting OGM vs TSM which validates previous case-series comparisons. There is a need for longer-term studies that are larger, prospective, randomized in order to fully elucidate efficacy given slow tendency for progression of meningioma in order to develop a more rigorous approach selection algorithm.

Racial Disparity Among Women Diagnosed With Invasive Breast Cancer in a Large Integrated Health System

Purpose

Reasons for the well-described disparity in outcomes between African American (AA) and non-Hispanic white (NHW) women with invasive breast cancer are unclear, making it difficult to identify solutions. This study examined the effects of demographics, biomarkers, tumor characteristics, cancer stage, morphology, and treatment variables on overall and cancer-free survival in these patient populations.

Methods

We retrospectively reviewed data for 6231 patients diagnosed with invasive breast cancer throughout an integrated health system from January 2006 through March 2015. Included for analysis were 5023 NHW and 413 AA women. All category and continuous variables in the study were described in the two groups using appropriate statistics. Kaplan-Meier method of survival with log-rank test was used to compare the two racial groups (NHW and AA). Cox proportional hazards regression was used to find hazard ratios for the predictors of survival and recurrence-free survival probability. Propensity probability match method (1:1) was used to match 319 NSW women to 319 similar AA women. Matching was done using all significant predictors, including demographic variables.

Results

Compared to NHW women, AA women presented with invasive breast cancer at a younger age (P<0.001) and had a higher proportion of stage IV cancers (P<0.001), which were more often infiltrating ductal carcinoma (P<0.003) and poorly differentiated (P<0.001). Within 10-year follow-up, AA women had shorter overall and recurrence-free survival (log-rank P<0.001), were 1.4 times more likely to die (P=0.009), and were twice as likely to have recurrence (P<0.001) than NHW women. In the matched groups, overall survival was similar for AA and NHW (log-rank P=0.0793); however, recurrence-free survival was higher in NHW than in AA women (P=0.047).

Conclusions

When presenting characteristics of AA and NHW women with invasive breast cancer are matched, disparity in overall mortality and rate of recurrence appears to be reduced or perhaps eliminated, suggesting invasive breast cancers in AA and NHW women respond similarly to treatment. Further study is needed to explore the true effect of biological factors; however, rectifying delivery of and access to care might be expected to mitigate, in large part, the racial disparity currently seen in breast cancer outcomes.

MGMT inhibition in ER positive breast cancer leads to CDC2, TOP2A, AURKB, CDC20, KIF20A, Cyclin A2, Cyclin B2, Cyclin D1, ERα and Survivin inhibition and enhances response to temozolomide

The DNA damage repair enzyme, O6-methylguanine DNA methyltransferase (MGMT) is overexpressed in breast cancer, correlating directly with estrogen receptor (ER) expression and function. In ER negative breast cancer the MGMT promoter is frequently methylated. In ER positive breast cancer MGMT is upregulated and modulates ER function. Here, we evaluate MGMT's role in control of other clinically relevant targets involved in cell cycle regulation during breast cancer oncogenesis. We show that O6-benzylguanine (BG), an MGMT inhibitor decreases CDC2, CDC20, TOP2A, AURKB, KIF20A, cyclin B2, A2, D1, ERα and survivin and induces c-PARP and p21 and sensitizes ER positive breast cancer to temozolomide (TMZ). Further, siRNA inhibition of MGMT inhibits CDC2, TOP2A, AURKB, KIF20A, Cyclin B2, A2 and survivin and induces p21. Combination of BG+TMZ decreases CDC2, CDC20, TOP2A, AURKB, KIF20A, Cyclin A2, B2, D1, ERα and survivin. Temozolomide alone inhibits MGMT expression in a dose and time dependent manner and increases p21 and cytochrome c. Temozolomide inhibits transcription of TOP2A, AURKB, KIF20A and does not have any effect on CDC2 and CDC20 and induces p21. BG+/-TMZ inhibits breast cancer growth. In our orthotopic ER positive breast cancer xenografts, BG+/-TMZ decreases ki-67, CDC2, CDC20, TOP2A, AURKB and induces p21 expression. In the same model, BG+TMZ combination inhibits breast tumor growth in vivo compared to single agent (TMZ or BG) or control. Our results show that MGMT inhibition is relevant for inhibition of multiple downstream targets involved in tumorigenesis. We also show that MGMT inhibition increases ER positive breast cancer sensitivity to alkylator based chemotherapy.

Abstract 4831: DSF-Cu complex sensitizes patient-derived unmethylated MGMT expressing brain tumor cells to temozolomide

Introduction: O6 methylguanine DNA methyltransferase (MGMT) repairs the DNA damage caused by alkylating agents [temozolomide (TMZ)] leading to chemoresistence. Members of the aldehyde dehydrogenase (ALDH) family of isoenzymes serve as markers of cancer stem cells and contribute to chemotherapy resistance. Disulfiram (DSF) inhibits MGMT through ubiquitin mediated degradation; it is also a specific inhibitor of ALDH. We therefore, hypothesized that DSF through MGMT and ALDH inhibition decreases stemness and sensitizes GBM cells to TMZ.

Methods: Normal astrocytes as well as established MGMT expressing GBM cell lines (LN18, T98G, U138, U118) and MGMT expressing (unmethylated) patient derived glioblastoma cells (ANII 7730 and ANII 7754) were treated with DSF/Cu +/- TMZ in various doses and combinations. We have also evaluated MGMT, ALDH levels and Sox2 expression. Cell viability, apoptotic assay and caspase 3/7 assay were used to evaluate inhibitory effect of various treatment combinations.

Results: DSF and TMZ have a minimal effect on normal astrocyte growth. DSF alone inhibited MGMT in established MGMT expressing glioblastoma cells (5 to 10 µM). DSF alone was unable to inhibit MGMT in patient derived brain tumor cells (up to 20µM). Addition of copper (&lt;/=1µM) significantly inhibited MGMT (~ 90%) in patient derived GBM cells which correlated with significant growth inhibition even when DSF was used at low concentrations (&lt;/=1µM). This suggests that addition of copper to DSF may reduce any potential, dose dependent DSF related neurotoxicity. Temozolomide alone did not inhibit MGMT in established cell lines nor patient derived brain tumor cell lines (up to 1000µM). DSF+Cu further sensitized patient derived GBM cells to TMZ and significantly inhibited GBM cell growth (~ 95%) and did not inhibit normal astrocyte growth. Further DSF+Cu and DSF+Cu+TMZ combinations caused significant apoptotic cell death and significantly increased caspase 3/7 in patient derived unmethylated GBM cells. Similarly, combination of DSF+Cu and TMZ+DSF+Cu caused significant drop in ALDH activity in patient derived brain tumor cells compared to untreated controls and single agents. DSF induced ALDH and MGMT inhibition correlated with decrease in SOX2. MGMT expression canceled by CRISPR/Cas9 led to significant decrease in SOX2 expression in primary cell cultures.

Conclusions: Our findings suggest that DSF/Cu treatment, a dual MGMT and ALDH inhibitor, suppresses stemness. Furthermore, our results confirm that combination of TMZ and DSF/Cu significantly inhibited glioblastoma cell growth compared to TMZ alone and untreated controls.

Citation Format: George C. Bobustuc, Amin B. Kassam, Richard A. Rovin, Deborah Donohoe, Dmitry Bosenko, Santhi D. Konduri. DSF-Cu complex sensitizes patient-derived unmethylated MGMT expressing brain tumor cells to temozolomide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4831.

Abstract TP367: Thrombolysis After Protamine Reversal Of Heparin For Acute Ischemic Stroke Post Cardiac Catheterization Case Report And Literature Review

Introduction: Most acute ischemic stroke (AIS) patients post cardiac catheterization are excluded from intravenous thrombolysis therapy because of prolonged PTT from heparin during the procedure. The outcome of these patients are unfavorable with high mortality.

Method: Case report and literature review.

Results: An 87-year-old man with diabetes mellitus, hypertension, neurofibromatosis, and hyperlipidemia underwent an elective trans-radial cardiac catheterization for abnormal stress test evaluation. He had 2 drug-eluting stents for severe stenosis of mid circumflex and right coronary arteries. He received heparin 13,000 IU during procedure. He developed acute left hemiparesis with initial NIH stroke scale (NIHSS) of 4. CT brain and CT angiogram of head and neck were unremarkable. Bedside activated clotting time (ACT) was 181. Protamine 40 mg was administered and ACT levels were at 138 when it was repeated after 30 minutes.Intravenous tissue plasminogen activator (IV tPA) was administered at 4 hours 25 minutes from his last known well. Within 15 minutes, his NIHSS was 0. Brain MRI showed no acute infarction 24 hours post stroke. To our knowledge, Only 5 AIS cases post cardiac catheterization received protamine prior IV-tPA administration. Three cases received only 0.6 mg/kg of IV- tPA dose. The mean initial NIHSS was 10 (range: 4-16) and mean discharge NIHSS was 1 (range: 0-2). They all have favorable outcomes and no intracranial hemorrhage were reported.

Conclusion: Protamine reversal of heparin for AIS post cardiac catheterization seems to be safe. Further studies are needed to confirm the therapeutic safety and efficacy of this strategy.

Abstract WP308: Low Volume of Acute Stroke Intervention in Aurora Health Care System Analysis

Introduction: Thrombectomy for acute ischemic stroke (AIS) is an important intervention, though the majority of eligible patients do not receive it. Drawing upon data from our high volume comprehensive stroke center, we identified barriers to recognizing patients with large vessel occlusion and subsequent impediments to treatment.

Methods: This is a retrospective chart review of patients presenting with AIS within 24 hours to the 14 hospitals within the AHCS between January 2015 and December 2016. Demographic, National Institutes of Health Stroke Scale (NIHSS) score, vascular imaging, and thrombectomy data were collected and analyzed. Large vessel occlusion (LVO) involved the distal internal carotid artery (ICA), middle cerebral artery (M1), or basilar artery (BA).

Results: Three thousand five hundred ninety- five AIS patients were identified. The median age was 61 years and 1863 (52%) were female. Two thousand one hundred eighty-three patients presented within 24 hours (61%): 1105 ≤ 6 hours. More than one third of AIS patients (773) did not have acute intracranial vascular imaging. Of 1410 patients with vascular imaging, 171 patients (12 %) had LVO. The site of occlusion was: M1, 86 patients (50.3%); distal ICA, 51 (30%); and BA, 27 (16%). Only 75 LVO patients (44%) had acute stroke intervention of whom 57 (77%) had mechanical thrombectomy, additional intra-arterial thrombolysis was given in 14 (19%) and 4 (5%) had intra-arterial thrombolysis as monotherapy. Successful revascularization (mTICI 2b-3) was achieved in 53 patients (70%). The main reasons that LVO patients did not receive acute stroke intervention include: late onset or unknown onset in 32 (35%), large core infarction 25 (27%), rapid improving NIHSS in 6 (7%), and unclear reason in 25 (17%),

Conclusion: There are several reasons that LVO is under recognized: a non neurologist often evaluates the patient in the ER first and they might not be familiar with stroke protocol guidelines; some LVO patients have an atypical presentation; and some patients refuse intervention. Based on our data, there is a need for continuing education of stroke care providers, particularly in this period of changing interventional guidelines.

Abstract 2035: MGMT inhibition leads to CDK4/6 inhibition and enhances palbociclib and abemaciclib activity in breast cancer

Background: MGMT (O6 methylguanine DNA methyltransferase), a DNA repair protein leading to chemotherapy resistance, increasingly studied for its cell cycle regulatory functions, also known to control ER expression and function, is overexpressed in a majority of cancers, including breast cancer. MGMT inhibition has been reported to restore ER function and sensitivity to hormonal therapy in tamoxifen resistant breast cancer. CDK4/6 is a cell cycle regulator targeted by a new class of drugs in the treatment of breast cancer in patients who had progressed during prior endocrine therapy. We investigated a potential correlative role between MGMT and CDK4/6 expression/activity. In this therapeutic context MGMT inhibition would have the dual role of increasing/restoring effect of endocrine therapy and facilitate activity of CDK4/6 inhibitors (Palbociclib and Abemaciclib).

Methods: We have tested the effect of Antabuse (disulfiram, DSF), as an MGMT inhibitor, at nontoxic doses, on the expression of CDK4/6, or in combination with Palbociclib (PB) or Abemaciclib (LY2835219 - LY) on ER+ breast cancer cells.

Results: DSF at very low doses (achievable in human serum with standard DSF clinical dosing) decreases ER+ breast cancer cell growth (MCF7, T47D and ZR75) in a dose-dependent manner. DSF further sensitizes breast cancer cells to PB or/and LY and significantly inhibits breast cancer growth without causing unwanted side effects on the normal breast epithelial cells. Dose effect and isobologram studies confirm synergistic activity of DSF + LY and moderate synergism for DSF + PB. DSF, alone or in combination with PB (DSF ± PB) and/or LY (DSF ± LY), significantly inhibits expression of MGMT, CDK4/6, ERα and aldehyde dehydrogenase activity - all involved in breast cancer cell cycle proliferation and tumorigenesis. Furthermore, PB and LY dose dependently decreased MGMT and CDK4 expression in breast cancer cells and significantly accumulated breast cancer cells in G1 phase of the cell cycle. DSF, alone or in combination with PB (DSF ± PB) and/or LY (DSF ± LY) caused significant apoptosis in breast cancer cells. DSF inhibited colony formation which was further enhanced by addition of PB/LY (DSF ± PB/LY). Similarly, DSF alone or in combination with PB (DSF ± PB) and/or LY (DSF ± LY) decreased the metastatic potential of breast cancer cells.

Conclusions: Our findings suggest that DSF as an MGMT inhibitor significantly enhances the antitumor effect of CDK4/6 inhibitors (PB or LY) in ER+ breast cancer.

Citation Format: George C. Bobustuc, Amin B. Kassam, Richard A. Rovin, Deborah L. Donohoe, Maxwell Albiero, Tarun Jella, Olivia Fukui, Cameron Piron, Santhi D. Konduri. MGMT inhibition leads to CDK4/6 inhibition and enhances palbociclib and abemaciclib activity in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2035. doi:10.1158/1538-7445.AM2017-2035

Initial experience with a robotically operated video optical telescopic-microscope in cranial neurosurgery: feasibility, safety, and clinical applications

OBJECTIVE

The move toward better, more effective optical visualization in the field of neurosurgery has been a focus of technological innovation. In this study, the authors’ objectives are to describe the feasibility and safety of a new robotic optical platform, namely, the robotically operated video optical telescopic-microscope (ROVOT-m), in cranial microsurgical applications.

METHODS

A prospective database comprising patients who underwent a cranial procedure between April 2015 and September 2016 was queried, and the first 200 patients who met the inclusion criteria were selected as the cohort for a retrospective chart review. Only adults who underwent microsurgical procedures in which the ROVOT-m was used were considered for the study. Preoperative, intraoperative, and postoperative data were retrieved from electronic medical records. The authors address the feasibility and safety of the ROVOT-m by studying various intraoperative variables and by reporting perioperative morbidity and mortality, respectively. To assess the learning curve, cranial procedures were categorized into 6 progressively increasing complexity groups. The main categories of pathology were I) intracerebral hemorrhages (ICHs); II) intraaxial tumors involving noneloquent regions or noncomplex extraaxial tumors; III) intraaxial tumors involving eloquent regions; IV) skull base pathologies; V) intraventricular lesions; and VI) cerebrovascular lesions. In addition, the entire cohort was evenly divided into early and late cohorts.

RESULTS

The patient cohort comprised 104 female (52%) and 96 male (48%) patients with a mean age of 56.7 years. The most common pathological entities encountered were neoplastic lesions (153, 76.5%), followed by ICH (20, 10%). The distribution of cases by complexity categories was 11.5%, 36.5%, 22%, 20%, 3.5%, and 6.5% for Categories I, II, II, IV, V, and VI, respectively. In all 200 cases, the surgical goal was achieved without the need for intraoperative conversion. Overall, the authors encountered 3 (1.5%) major neurological morbidities and 6 (3%) 30-day mortalities. Four of the 6 deaths were in the ICH group, resulting in a 1% mortality rate for the remainder of the cohort when excluding these patients. None of the intraoperative complications were considered to be attributable to the visualization provided by the ROVOT-m. When comparing the early and late cohorts, the authors noticed an increase in the proportion of higher-complexity surgeries (Categories IV–VI), from 23% in the early cohort, to 37% in the late cohort (p = 0.030). In addition, a significant reduction in operating room setup time was demonstrated (p < 0.01).

CONCLUSIONS

The feasibility and safety of the ROVOT-m was demonstrated in a wide range of cranial microsurgical applications. The authors report a gradual increase in case complexity over time, representing an incremental acquisition of experience with this technology. A learning curve of both setup and execution phases should be anticipated by new adopters of the robot system. Further prospective studies are required to address the efficacy of ROVOT-m. This system may play a role in neurosurgery as an integrated platform that is applicable to a variety of cranial procedures.

Development of an iPhone application for sideline concussion testing

Professional athletes are taking concussion very seriously, and missed play due to concussion is no longer stigmatized. One fortuitous consequence is increased awareness of the detrimental effects of concussion among student athletes. Whereas professional athletes have access to formal in-competition evaluation and out-of-competition monitoring programs, the majority of student athletes, especially at the middle school and high school levels, do not. The authors therefore set out to create an easy-to-use iPhone application for sideline concussion testing and serial monitoring of these at-risk athletes.

Expression of O6-methylguanine-deoxyribose nucleic acid methyltransferase and temozolomide response in a patient with a malignant spinal cord astrocytoma. Case report

The authors report the case of a 28-year-old woman with a high-grade spinal cord astrocytoma. Treatment using surgery, radiation, and temozolomide (TMZ) led to functional recovery and regression of the residual tumor as demonstrated on serial magnetic resonance images. Genetic testing revealed that this tumor did not express the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT). This is the first report in the literature correlating MGMT expression with the clinical response of a high-grade spinal cord astrocytoma treated using TMZ.

Pokemon expression in malignant glioma: an application of bioinformatics methods

OBJECT

In this report the authors review the role of bioinformatics in the design of a research project in which the molecular genetics of malignant glioma were studied. A project to characterize Pokemon expression in malignant glioma was developed, refined, and implemented using bioinformatics methods.

METHODS

Using the resources available from the National Center for Biotechnology Information, the messenger RNA (mRNA) sequence for Pokemon was determined. With this information and online primer design tools, novel primers were designed that would specifically amplify Pokemon mRNA by using reverse transcription-polymerase chain reaction assays.

CONCLUSIONS

The promise of bioinformatics is in the rapid and widespread dissemination and analysis of genomic information. This information is then used in research investigating the genetic basis of disease. In this paper the authors review the bioinformatics methods used in their study of Pokemon expression in malignant glioma.

Complications in three-column cervical spine injuries requiring anterior-posterior stabilization

A study was undertaken to elicit the hidden factors that, when identified, would signal the presence of cervical spine instability. Data were derived from the records and radiographs of 21 patients having sustained traumatic injury to the lower cervical spine (C3-C7) and who failed a single-stage posterior stabilization procedure necessitating a second (or combined) anterior-posterior arthrodesis. Mechanism of injury most frequently identified in this group was the distraction-flexion (locked facets) pattern (nine patients) and the "tear drop" compression-flexion injury pattern (seven patients). All 21 patients underwent a posterior wiring and bone graft stabilization procedure with persistent postoperative instability. Thus, failure to recognize the presence of "three-column" instability, the sine qua non of this group, resulted in the failure of posterior tension band stabilization as a means of gaining cervical spine stability. Three-column cervical spine instability is suspected in the presence of: 1) retrolisthesis and angulation of the superior vertebra on the next inferior vertebra; 2) distraction of the posterior interspinous ligaments sufficient to allow subluxation or dislocation of the facets; in conjunction with 3) a "shear" dislocation of one vertebra on another. Anterior shearing force through the disc space is capable of disrupting the intervertebral disc, along with disruption of the anterior and posterior longitudinal ligaments, each contributing to the presence of anterior and middle column cervical spine instability.

Traumatic spondylolisthesis of the lower cervical spine: case report

A case of traumatic spondylolisthesis of C6 and C7 is presented. The mechanism of injury and the therapeutic implications are discussed.

Thermal effects of the Nd:YAG and carbon dioxide lasers on the central nervous system

The use of laser is becoming commonplace in neurological surgery because of the potential for surgical precision with minimal surrounding trauma, improved hemostasis, freedom from electrical interference of evoked potentials recordings, and a variety of other benefits. Despite this enthusiasm, there are little significant data regarding various laser-neural tissue interactions. Thermal transformation was studied using both carbon dioxide and Nd: YAG lasers on rat cerebral cortex. The Nd: YAG laser produced a significant quantity of heat which spread far beyond the boundaries of the histologically identified lesion. The thermal profile of the carbon dioxide laser on brain indicated minimal thermal spread change, even immediately adjacent to the physical edge of the lesion. Mechanisms and ramifications are discussed.