Stereotactic radiosurgery in the management of non-small cell lung cancer brain metastases: a prospective study using the NeuroPoint Alliance Stereotactic Radiosurgery Registry

OBJECTIVE

The literature on non-small cell lung cancer (NSCLC) brain metastases (BMs) managed using stereotactic radiosurgery (SRS) relies mainly on single-institution studies or randomized controlled trials (RCTs). There is a literature gap on clinical and radiological outcomes of SRS for NSCLC metastases in real-world practice. The objective of this study was to benchmark mortality and progression outcomes in patients undergoing SRS for NSCLC BMs and identify risk factors for these outcomes using a national quality registry.

METHODS

The SRS Registry of the NeuroPoint Alliance was used for this study. This registry included patients from 16 enrolling sites who underwent SRS from 2017 to 2022. Data are prospectively collected without a prespecified research purpose. The main outcomes of this analysis were overall survival (OS), out-of-field recurrence, local progression, and intracranial progression. All time-to-event investigations included Kaplan-Meier analyses and multivariable Cox regressions.

RESULTS

Two hundred sixty-four patients were identified, with a mean age of 66.7 years and a female proportion of 48.5%. Most patients (84.5%) had a Karnofsky Performance Status (KPS) score of 80-100, and the mean baseline EQ-5D score was 0.539 quality-adjusted life years. A single lesion was present in 53.4% of the patients, and 29.1% of patients had 3 or more lesions. The median OS was 28.1 months, and independent predictors of mortality included no control of primary tumor (hazard ratio [HR] 2.1), KPS of 80 (HR 2.4) or lower (HR 2.4), coronary artery disease (HR 2.8), and 5 or more lesions present at the time of SRS treatment (HR 2.3). The median out-of-field progression-free survival (PFS) was 24.8 months, and the median local PFS was unreached. Intralesional hemorrhage was an independent risk factor of local progression, with an HR of 6.0. The median intracranial PFS was 14.0 months and was predicted by the number of lesions at the time of SRS (3-4 lesions, HR 2.2; 5-14 lesions, HR 2.5).

CONCLUSIONS

In this real-world prospective study, the authors used a national quality registry and found favorable OS in patients with NSCLC BMs undergoing SRS compared with results from previously published RCTs. The intracranial PFS was mainly driven by the emergence of new lesions rather than local progression. A greater number of lesions at baseline was associated with out-of-field progression, while intralesional hemorrhage at baseline was associated with local progression.

CTIM-27. AUTOLOGOUS TUMOR LYSATE-LOADED DENDRITIC CELL VACCINATION IMPROVES SURVIVAL IN PATIENTS WITH NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA: SURVIVAL RESULTS FROM A PHASE 3 TRIAL

BACKGROUND

Standard of care (SOC) and patient survival in glioblastoma have changed little in the past 17 years. We evaluated in a phase 3 trial whether adding an autologous tumor lysate-loaded dendritic cell vaccine (murcidencel) to SOC extends survival. Patients and

METHODS

Newly diagnosed glioblastoma patients were randomized 2:1 to either murcidencel or placebo. Under a crossover design, all patients could receive murcidencel following tumor recurrence. All parties remained blinded regarding treatments before recurrence. Patients thus received murcidencel at new diagnosis (nGBM) or at recurrence (rGBM) following crossover from placebo. The primary and secondary endpoints compare overall survival (OS) with contemporaneous, matched external controls. Four sets of analyses were conducted to ensure rigorous matching of the controls, reduce biases, and confirm the robustness of the results.

RESULTS

331 patients were enrolled. With the crossover, 89% received murcidencel. Median OS (mOS) for nGBM patients (n = 232) was 19.3 months from randomization (22.4 months from surgery) with murcidencel vs. 16.5 months from randomization in the controls (HR = 0.80, p = 0.002). Survival at 48 months from randomization was 15.7% vs. 9.9%, and at 60 months was 13% vs. 5.7%. For rGBM (n = 64), mOS was 13.2 months from relapse vs. 7.8 months in the controls (HR = 0.58, p < 0.001). Survival at 24 months post-recurrence was 20.7% vs. 9.6%, and at 30 months post-recurrence was 11.1% vs 5.1%. In nGBM patients with methylated MGMT (n = 90), mOS was 30.2 months from randomization (33 months from surgery) with murcidencel vs. 21.3 months from randomization in the controls (HR = 0.74, p = 0.027). The treatment was well tolerated, with only 5 serious adverse events deemed at least possibly related to the vaccine.

CONCLUSION

Clinically meaningful and statistically significant survival extension was seen in both nGBM and rGBM patients treated with murcidencel and SOC compared with contemporaneous, matched external controls who received SOC alone.

Lumbar cistern Candida intradural abscess following epidural anesthesia

Background:

This report describes a case of an immunocompetent patient with an intradural abscess from Candida dubliniensis. The majority of fungal spine infections, although rare in general, are due to Aspergillus or C. albicans through systemic fungemia. To date, there have only been two reports of spondylodiscitis from C. dubliniensis.

Case Description:

A 37-year-old immunocompetent female patient presented to the neurosurgical service for worsening headaches with nausea, vomiting, vision changes, and weight loss. MRI studies showed diffuse leptomeningeal enhancement of the distal spinal cord, conus medullaris, and nerve roots of the cauda equina extending beyond the neural foramina bilaterally. She had persistent symptoms and no clear diagnosis on lumbar puncture or systemic testing therefore L5-S1 laminectomy for an intradural tissue biopsy was performed. During surgery, cultures were taken and grew colonies of C. dubliniensis.

Conclusion:

This organism has been reported rarely in the literature as being an infectious agent, thus diagnosing remains a challenge but should be considered in patients with a suggestive history.

Factors associated with progression and mortality among patients undergoing stereotactic radiosurgery for intracranial metastasis: results from a national real-world registry

OBJECTIVE

Stereotactic radiosurgery (SRS) has been increasingly employed in recent years to treat intracranial metastatic lesions. However, there is still a need for optimization of treatment paradigms to provide better local control and prevent progressive intracranial disease. In the current study, the authors utilized a national collaborative registry to investigate the outcomes of patients with intracranial metastatic disease who underwent SRS and to determine factors associated with lesion treatment response, overall progression, and mortality.

METHODS

The NeuroPoint Alliance SRS registry was queried for all patients with intracranial metastatic lesions undergoing single- or multifraction SRS at participating institutions between 2016 and 2020. The main outcomes of interest included lesion response (lesion-level analysis), progression using Response Assessment for Neuro-Oncology criteria, and mortality (patient-level analysis). Kaplan-Meier analysis was used to report time to progression and overall survival, and multivariable Cox proportional hazards analysis was used to investigate factors associated with lesion response, progression, and mortality.

RESULTS

A total of 501 patients (1447 intracranial metastatic lesions) who underwent SRS and had available follow-up were included in the current analyses. The most common primary tumor was lung cancer (49.5%, n = 248), followed by breast (15.4%, n = 77) and melanoma (12.2%, n = 61). Most patients had a single lesion (44.9%, n = 225), 29.3% (n = 147) had 2 or 3 lesions, and 25.7% (n = 129) had > 3 lesions. The mean sum of baseline measurements of the lesions according to Response Evaluation Criteria in Solid Tumors (RECIST) was 35.54 mm (SD 25.94). At follow-up, 671 lesions (46.4%) had a complete response, 631 (43.6%) had a partial response (≥ 30% decrease in longest diameter) or were stable (< 30% decrease but < 20% increase), and 145 (10%) showed progression (> 20% increase in longest diameter). On multivariable Cox proportional hazards analysis, melanoma-associated lesions (HR 0.48, 95% CI 0.34-0.67; p < 0.001) and larger lesion size (HR 0.94, 95% CI 0.93-0.96; p < 0.001) showed lower odds of lesion regression, while a higher biologically effective dose was associated with higher odds (HR 1.001, 95% CI 1.0001-1.00023; p < 0.001). A total of 237 patients (47.3%) had overall progression (local failure or intracranial progressive disease), with a median time to progression of 10.03 months after the index SRS. Factors found to be associated with increased hazards of progression included male sex (HR 1.48, 95% CI 1.108-1.99; p = 0.008), while administration of immunotherapy (before or after SRS) was found to be associated with lower hazards of overall progression (HR 0.62, 95% CI 0.460-0.85; p = 0.003). A total of 121 patients (23.95%) died during the follow-up period, with a median survival of 19.4 months from the time of initial SRS. A higher recursive partitioning analysis score (HR 21.3485, 95% CI 1.53202-3.6285; p < 0.001) was found to be associated with higher hazards of mortality, while single-fraction treatment compared with hypofractionated treatment (HR 0.082, 95% CI 0.011-0.61; p = 0.015), administration of immunotherapy (HR 0.385, 95% CI 0.233-0.64; p < 0.001), and presence of single compared with > 3 lesions (HR 0.427, 95% CI 0.187-0.98; p = 0.044) were found to be associated with lower risk of mortality.

CONCLUSIONS

The comparability of results between this study and those of previously published clinical trials affirms the value of multicenter databases with real-world data collected without predetermined research purpose.

INNV-09. CLINICAL EFFICACY OF TUMOR TREATING FIELDS FOR NEWLY DIAGNOSED GLIOBLASTOMA

Recent clinical trials demonstrated that adding tumor treating fields (TTF) to radiotherapy and temozolomide chemotherapy (the Stupp protocol) increased survival for glioblastoma (GBM) patients. However, data is lacking on the magnitude of this survival effect when the regimen is used outside of a clinical trial as part of routine clinical practice. In the present study, we retrospectively identified adult patients with newly diagnosed GBM (n = 240) treated with the Stupp protocol at our institution from January 2005 to July 2017. We grouped patients into two time periods for comparison: 2005–2013 (group 1, Stupp protocol) and 2014–2017 (group 2, TTF+ Stupp protocol). Thirty-six percent (37/104) of patients in group 2 received TTF in conjunction with the Stupp protocol. Within group 2, the 37-patients who received TTF + Stupp had increased 6-month and 1-year survival rates compared to the 67-patients who received Stupp alone (97.1% vs. 75.7%, p = 0.006; 67.6% vs. 53.7%, p = 0.170, respectively). The improvement of survival rate at 6-month was further confirmed by a modified Poisson model (RR: 1.23, p = 0.010) adjusting for sex, age, performance status and extent of resection. However, we did not observe improvements in overall survival (OS) with a Cox model with TTF treatment modeled as a time-dependent covariate (HR = 0.87, p = 0.599). Furthermore, we did not find that the addition of TTF as a treatment option in our center significantly improved OS for patients in group 2 when compared to those in group 1 (429.0 vs. 395.0 days, p = 0.138). Therefore, while adding TTF to the Stupp protocol appeared to benefit patients with newly diagnosed GBM, this effect may be largely due to selection bias. Comprehensive studies including large number of patients as well as longer follow-up time are needed to validate our results.

Single-Fraction Radiosurgery Using Conservative Doses for Brain Metastases: Durable Responses in Select Primaries With Limited Toxicity

BACKGROUND

Optimal doses for single-fraction stereotactic radiosurgery (SRS) in the treatment of brain metastases are not well established. Our institution utilized conservative dosing compared to maximum-tolerated doses from the Radiation Therapy Oncology Group 90-05 Phase I study.

OBJECTIVE

To report individual lesion control (LC) from conservative single-fraction doses and determine factors affecting LC.

METHODS

From 2003 to 2015, patients who underwent linear accelerator-based single-fraction SRS for cerebral/cerebellar metastases and receiving at least 1 follow-up magnetic resonance imaging (MRI) were identified. Lesion response was assessed by a size-based rating system and modified "Response Assessment in Neuro-Oncology Brain Metastases" (RANO-BM) criteria.

RESULTS

Among 188 patients with 519 lesions, median survival was 13.1 mo; median follow-up time with MRI was 9.6 mo per course. Median tumor-periphery dose was 15 Gy (range: 7.5-20.7). Median lesion volume was 0.5 cc and diameter was 9 mm (range: 2-45). Concordance between RANO-BM and size-based system was 93%. Crude 1-yr LC was 80%, 73%, 56%, and 38% for lesions 1 to 10, 11 to 20, 21 to 30, >31 mm, respectively. On multivariate analysis, increased size, melanoma and colorectal histology, and progression after whole brain radiation therapy predicted worse LC. When excluding lesions treated as a boost, dose was a significant predictor of LC in multivariate models (hazard ratio 0.89, P = .01). Symptomatic radiation necrosis occurred in 10 lesions in 10 patients.

CONCLUSION

Histology predicts LC after conservative SRS doses with evidence of a dose-response relationship. Conservative single-fraction SRS doses confer minimal toxicity and acceptable control in certain subgroups (breast cancer, <5 mm), with suboptimal control in larger lesions and in combination with whole brain radiation therapy.

Translational Brain Mapping at the University of Rochester Medical Center: Preserving the Mind Through Personalized Brain Mapping

The Translational Brain Mapping Program at the University of Rochester is an interdisciplinary effort that integrates cognitive science, neurophysiology, neuroanesthesia, and neurosurgery. Patients who have tumors or epileptogenic tissue in eloquent brain areas are studied preoperatively with functional and structural MRI, and intraoperatively with direct electrical stimulation mapping. Post-operative neural and cognitive outcome measures fuel basic science studies about the factors that mediate good versus poor outcome after surgery, and how brain mapping can be further optimized to ensure the best outcome for future patients. In this article, we describe the interdisciplinary workflow that allows our team to meet the synergistic goals of optimizing patient outcome and advancing scientific understanding of the human brain.

Domain-Specific Diaschisis: Lesions to Parietal Action Areas Modulate Neural Responses to Tools in the Ventral Stream

Neural responses to small manipulable objects ("tools") in high-level visual areas in ventral temporal cortex (VTC) provide an opportunity to test how anatomically remote regions modulate ventral stream processing in a domain-specific manner. Prior patient studies indicate that grasp-relevant information can be computed about objects by dorsal stream structures independently of processing in VTC. Prior functional neuroimaging studies indicate privileged functional connectivity between regions of VTC exhibiting tool preferences and regions of parietal cortex supporting object-directed action. Here we test whether lesions to parietal cortex modulate tool preferences within ventral and lateral temporal cortex. We found that lesions to the left anterior intraparietal sulcus, a region that supports hand-shaping during object grasping and manipulation, modulate tool preferences in left VTC and in the left posterior middle temporal gyrus. Control analyses demonstrated that neural responses to "place" stimuli in left VTC were unaffected by lesions to parietal cortex, indicating domain-specific consequences for ventral stream neural responses in the setting of parietal lesions. These findings provide causal evidence that neural specificity for "tools" in ventral and lateral temporal lobe areas may arise, in part, from online inputs to VTC from parietal areas that receive inputs via the dorsal visual pathway.

Clinical efficacy of tumor-treating fields for newly diagnosed glioblastoma

2046

Background: Recent clinical trials have shown that adding tumor treating fields (TTF) to the Stupp protocol (SP) has increased survival after glioblastoma (GBM) diagnosis. However, whether this regimen improves population-based survival for patients with GBM remains unknown. Methods: We retrospectively identified adult patients with newly diagnosed GBM treated at our institution from January 2000 to July 2017 (n = 438, median age: 63 years).We grouped patients into three time periods for comparison: 2000-2004 (group 1, prior to SP), 2005-2013 (group 2, SP) and 2014-2017 (group 3, adding TTF to SP). The Kaplan-Meier method was used to estimate survival. Statistical analysis included unadjusted group comparisons by Chi-square and Log-rank tests and adjusted group comparisons using logistic and Cox models. Results: Thirty-seven percent (43/117) of patients with GBM in group 3 received TTF with SP therapy; when compared to those who received SP only, these patients had significant improvements in 6-month and 1-year overall survival (OS) rates (100.0% vs. 82.4%, p < 0.01; 86.0% vs. 66.2%, p < 0.05, respectively) (unadjusted for prognostic factors including sex, age, KPS and extent of resection) and an increased trend of median OS (479.0 vs. 448 days, p = 0.269). However, after adjusting for those prognostic factors, we didn’t find a statistically better survival for patients treated with TTF (OR: 6.156, p = 0.097, OR: 2.102, p = 0.185, respectively). Furthermore, multivariate Cox proportion hazards model after adjusting for those prognostic factors showed no significant survival benefits for patients treated with TTF and SP compared to those treated with SP only (HR = 0.797, p = 0.648). In addition, we didn’t find significant increases of 6-month, 1-year survival rates and median OS for patients in group 3 when compared to those in group 2 who had seen increased trends of survival trends when compared to those in group 1. Conclusions: Although adding TTF to SP appeared to benefit patients with GBM, this effect might be due to selection bias, e.g., TTF was offered to those patients with better prognostic factors. Ascertaining the long-term benefits of TTF requires further investigation.

Risk Factors and Associated Complications of Symptomatic Venous Thromboembolism in Patients with Craniotomy for Meningioma

OBJECTIVE

Patients undergoing surgical resection of meningioma are at increased risk for developing venous thromboembolism (VTE). The aim of this study was to assess occurrence of VTE in patients who underwent surgical resection of meningioma to determine risk factors and associated complications of VTE.

METHODS

The American College of Surgeons National Surgical Quality Improvement Project database from 2012 to 2015 was reviewed for patients who had undergone meningioma resection according to primary Current Procedural Terminology codes and International Classification of Diseases, Ninth Revision.

RESULTS

The study included 5036 patients with meningioma. Rate of VTE was 3.38%, with pulmonary embolism rate of 1.47% and deep venous thrombosis rate of 2.42%. During the first 30 days after surgery, patients with VTE had a mortality rate of 5.88% compared with 1.15% for patients without VTE. Multivariate binary logistic regression analysis determined 5 risk factors for VTE,: age ≥60 years, American Society of Anesthesiologists classification III, operative time ≥310 minutes, ventilator dependence, and preoperative transfusions. Univariate analysis revealed a number of complications significantly associated with VTE occurrence, including unplanned intubation, ventilator use for >48 hours, stroke, sepsis, septic shock, pneumonia, urinary tract infection, and transfusions.

CONCLUSIONS

Risk factors of VTE and associated complications were identified. Understanding these risk factors provides physicians with further insight in managing this subgroup of patients in a personalized fashion in the perioperative period to minimize the incidence and morbidity of VTE.

Optimierung der Bestrahlungsplanung beim nicht-kleinzelligen Bronchialkarzinom (NSCLC) mit Hilfe von 18FDG-PET

Ziel: Die FDG-PET-Untersuchung hat in den vergangenen Jahren bei onkologischen Fragestellungen insbesondere beim Staging des Bronchialkarzinoms wachsende Bedeutung erlangt. In der vorliegenden retrospektiven Untersuchung wurde der Einfluss der PET auf die Strahlentherapieplanung bei Patienten mit non-small-cell lung cancer (NSCLC) untersucht. Methoden: Die Untersuchung umfasste 39 Patienten mit einem NSCLC, die zwecks Staging mit PET untersucht worden waren. Sie wurden über (anhand der CT- und Bronchoskopiebefunde geplante) anterior/posteriore Gegenfelder bestrahlt, die den Primärtumor und das Mediastinum einschlossen. Die Ergebnisse der PET-Untersuchung wurden bei der Bestrahlungsplanung zunächst nicht berücksichtigt. Retrospektiv wurden anhand der FDG-Anreicherungen die Bestrahlungsfelder unter Berücksichtigung der Größe und Lokalisation des Primärtumors neu definiert, weiterhin wurde die Ausdehnung des mediastinalen Anteils der Feldkonturen auf PET-Aktivitäten außerhalb des Bestrahlungsfelds überprüft. Ergebnisse: Bei 15 von 39 Patienten unterschieden sich die CT- von den CT/PET-geplanten Bestrahlungsfeldern. In den meisten Fällen (n = 12) war das CT/PET-Feld kleiner als das CT-Feld. Die mediane Größe der Bestrahlungsfelder betrug 179 cm2 und nach Neudefinition durch PET 166 cm2. Bei 20 Patienten mit Tumor-verursachten Belüftungsstörungen (Atelektasen, Dystelektasen) wurde die Änderung des Bestrahlungsfelds signifikant häufiger (p = 0,03) als bei den übrigen Patienten vorgeschlagen. Schlussfolgerung: Unsere Ergebnisse zeigen den Synergismus von topographischer (CT) und metabolischer (FDG-PET) Information, die in der Bestrahlungsplanung des Bronchialkarzinoms insbesondere bei Patienten mit Belüftungsstörungen von Nutzen sein könnte.

Somatic mutation, copy number and transcriptomic profiles of primary and matched metastatic estrogen receptor-positive breast cancers

BACKGROUND

Estrogen receptor-positive (ER+) breast cancers (BCs) constitute the most frequent BC subtype. The molecular landscape of ER+ relapsed disease is not well characterized. In this study, we aimed to describe the genomic evolution between primary (P) and matched metastatic (M) ER+ BCs after failure of adjuvant therapy.

MATERIALS AND METHODS

A total of 182 ER+ metastatic BC patients with long-term follow-up were identified from a single institution. P tumor tissue was available for all patients, with 88 having matched M material. According to the availability of tumor material, samples were characterized using a 120 mutational hotspot qPCR, a 29 gene copy number aberrations (CNA) and a 400 gene expression panels. ESR1 mutations were assayed by droplet digital PCR. Molecular alterations were correlated with overall survival (OS) using the Cox proportional hazards regression models.

RESULTS

The median follow-up was 6.4 years (range 0.5-26.6 years). Genomic analysis of P tumors revealed somatic mutations in PIK3CA, KRAS, AKT1, FGFR3, HRAS and BRAF at frequencies of 41%, 6%, 5%, 2%, 1% and 2%, respectively, and CN amplification of CCND1, ZNF703, FGFR1, RSF1 and PAK1 at 23%, 19%, 17%, 12% and 11%, respectively. Mutations and CN amplifications were largely concordant between P and matched M (>84%). ESR1 mutations were found in 10.8% of the M but none of the P. Thirteen genes, among which ESR1, FOXA1, and HIF1A, showed significant differential expression between P and M. In P, the differential expression of 18 genes, among which IDO1, was significantly associated with OS (FDR < 0.1).

CONCLUSIONS

Despite the large concordance between P and matched M for the evaluated molecular alterations, potential actionable targets such as ESR1 mutations were found only in M. This supports the importance of characterizing the M disease. Other targets we identified, such as HIF1A and IDO1, warrant further investigation in this patient population.

Should Potential Risk of Chronic Traumatic Encephalopathy Be Discussed with Young Athletes?

As participation in youth sports has risen over the past two decades, so has the incidence of youth sports injuries. A common topic of concern is concussion, or mild traumatic brain injury, in young athletes and whether concussions sustained at a young age could lead to lifelong impairment such as chronic traumatic encephalopathy (CTE). While the pathway from a concussed young athlete to an adult with CTE remains unknown, current research is attempting to provide more clarity. This article discusses how health care professionals can help foster an informed, balanced decision-making process regarding participation in contact sports that involves the parents as well as the children.

mTOR activation is increased in pilocytic astrocytomas from older adults compared with children

BACKGROUND

Recent studies suggest that the behavior and biology of WHO grade I pilocytic astrocytomas (PAs) in adults is different than that associated with grade I PAs in children.

METHODS

We evaluated Ki-67 labeling, BRAF abnormalities, isocitrate dehydrogenase R132 immunoreactivity phosphorylation (activation) of p44/42 mitogen activated protein kinase (MAPK), and mammalian target of rapamycin (mTOR) in formalin-fixed tissue from 21 adult (18 years or older, mean age 37 years) and 10 children (mean age 9.4 years) WHO grade I PAs.

RESULTS

The mean Ki-67 labeling was 4.8% in adults and 3.8% in children. There was no significant difference between Ki-67 labeling in children and adults or either subgroups of adults. No differences were found in phospho p44/42MAPK in adult subgroups (18-33 years and 34 and older) compared to children. Activation/phosphorylation of mTOR was biphasic in adults being significantly lower than children in young adults but significantly higher than children in older adults (age 34 and older).

CONCLUSIONS

Identifying mTOR phosphorylation/activation may represent a difference in biology and a new marker to guide chemotherapy with recently approved mTOR inhibitors.

STAT3 activation and risk of recurrence in meningiomas

Several studies have suggested that activation of signal transducer and activator of transcription 3 (STAT3) is associated with initiation, progression and metastasis of numerous types of malignancy. However, the role of the Janus kinase-interleukin 6-STAT3 signaling pathway in the pathogenesis and recurrence of meningiomas is unknown. The present study evaluated STAT3 activation by western blotting and immunohistochemistry and assessed its association with Ki-67 labeling in 13 cases of meningioma in which frozen tissue and ≥5.5-year follow-up information were available, and in formalin-fixed meningioma tissues from 14 cases with an 8.4-year follow-up. The results of the western blot analysis indicated that STAT3 phosphorylation was markedly higher in grade II meningiomas compared with that in grade I, with mean densitometric values of 8.6 and 1.7 following normalization to actin, respectively. High STAT3 phosphorylation/activation was identified in 2 of 3 recurrent World Health Organization (WHO) grade I meningiomas and 0 of 3 non-recurrent meningiomas. Strong STAT3 phosphorylation/activation signal was also found in 2 of 4 recurrent grade II meningiomas and 1 of 3 non-recurrent cases. According to the immunohistochemistry results, phospho-STAT3 was not increased in WHO grade II tumors compared with that in grade I tumors, and was not significantly different between recurrent and non-recurrent cases. Ki-67 labeling was significantly increased in grade II vs. grade I tumors, and was also significantly increased in recurrent compared with non-recurrent grade I meningiomas. The results of the current study suggest that, while detection of phosphorylated/activated STAT3 may be useful in isolated cases, identifying activation may be of little value in predicting recurrence.

Abstract PD6-03: High prevalence and clonal heterogeneity of ESR1 mutations (mt) in circulating tumor DNA (ctDNA) from patients (pts) enrolled in FERGI, a randomized phase II study testing pictilisib (GDC-0941) in combination with fulvestrant (F) in pts that failed a prior aromatase inhibitor (AI)

Background: Mutations in the ligand binding domain of the estrogen receptor gene (ESR1) have been associated with resistance to AI therapy in pts with ER+ breast cancer. To assess if ESR1 status has prognostic or predictive significance in the post-AI metastatic setting ESR1 mutation status was analyzed in circulating tumor DNA (ctDNA) from 168 pts enrolled on the FERGI study (NCT01437566; Krop et al., SABCS 2014).

Methods: Baseline and longitudinal mutational analysis for hotspot mutations in ESR1 (E380Q, S463P, V534E, P535H, L536R/H/P, L536Q, Y537N/S/C, D538G) and PIK3CA (C420R, E542K, E545K/G, Q546K, M1043I, H1047Y/R/L) was performed using droplet digital PCR (ddPCR) on ctDNA derived from plasma. Archival tissue was analyzed via RT-PCR and ddPCR.

Results: Baseline ctDNA analysis demonstrated a total of 62/156 (40%) and 57/153 (37%) pts with PIK3CA and ESR1 mutations, respectively. The most common ESR1 mutations are D538G, Y537S, and E380Q, representing 54%, 33% and 26% of the pts with a detectable ESR1 mutation at baseline, respectively. There was a numeric increase of ESR1 mutations in patients with LumA (41/99, 41%) vs LumB disease (14/44, 31%). PIK3CA mutations in asynchronously collected archival tissue were 85% concordant with plasma ctDNA mutations (sensitivity 78%, specificity 91%). PIK3CA mutations in baseline ctDNA showed a higher median allele frequency (AF) than ESR1 mutations (3.6% vs 0.46%), consistent with PIK3CA being an early event and ESR1 mutations occurring later in pts with recurrent disease. Of the pts with a detectable ESR1 mutation at baseline (n=57), 23 (40%) pts had multiple ESR1 mutations and 10 (18%) had ≥3 ESR1 mutations. The PFS outcomes for patients with and without ESR1 mutations detected at baseline are summarized below, indicating no obvious prognostic or predictive effect for combination of F with pictilisib compared with F in these underpowered subsets.

ArmESR1 MT - mPFS (mo)ESR1 WT - mPFS (mo)HR (95% CI)F + placebo5.4 (30 pts, 24 events)3.7 (40 pts, 31 events)1.06 (0.62, 1.81)F+pictilisib5.8 (27 pts, 20 events)6.7 (56 pts, 34 events)1.36 (0.78, 2.38)

PIK3CA and ESR1 ctDNA analysis on serial plasma samples from 40 pts and the assessment of ESR1 mutation status in the patient's tumor sample by ddPCR is currently in progress and will be reported.

Conclusions: Mutations in ESR1 detected by ddPCR in patient plasma samples occur in nearly 40% of pts that failed a prior AI. The polyclonal nature of ESR1 mutations is consistent with the convergent evolution of multiple AI resistant subclones. While these conclusions should be interpreted with caution due to the relatively small sample size and post hoc nature of the analysis, this data does not support a prognostic or predictive PFS hypothesis for ESR1 mutations with F or in combination with pictilisib.

Citation Format: Spoerke J, Gendreau S, Johnston S, Schmid P, Krop I, Qui J, Derynck M, Chan I, Walter K, Amler L, Hampton G, Lackner M. High prevalence and clonal heterogeneity of ESR1 mutations (mt) in circulating tumor DNA (ctDNA) from patients (pts) enrolled in FERGI, a randomized phase II study testing pictilisib (GDC-0941) in combination with fulvestrant (F) in pts that failed a prior aromatase inhibitor (AI). [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 PD6-03.

Identification of Endoglin as an epigenetically regulated tumour-suppressor gene in lung cancer

Background:

The transforming growth factor-beta (TGF- β) pathway has been implicated in proliferation, migration and invasion of various cancers. Endoglin is a TGF-β accessory receptor that modulates signalling. We identified Endoglin as an epigenetically silenced tumour-suppressor gene in lung cancer by means of a genome-wide screening approach, then sought to characterise its effect on lung cancer progression.

Methods:

Methylation microarray and RNA sequencing were carried out on lung cancer cell lines. Epigenetic silencing of Endoglin was confirmed by methylation and expression analyses. An expression vector and a 20-gene expression panel were used to evaluate Endoglin function. Pyrosequencing was carried out on two independent cohorts comprising 112 and 202 NSCLC cases, respectively, and the impact of Endoglin methylation on overall survival (OS) was evaluated.

Results:

Methylation in the promoter region resulted in silencing of Endoglin, which could be reactivated by demethylation. Increased invasion coupled with altered EMT marker expression was observed in cell lines with an epithelial-like, but not those with a mesenchymal-like, profile when Endoglin was absent. Methylation was associated with decreased OS in stage I but not in stages II–III disease.

Conclusions:

We show that Endoglin is a common target of epigenetic silencing in lung cancer. We reveal a link between Endoglin silencing and EMT progression that might be associated with decreased survival in stage I disease.

Cool-1-mediated inhibition of c-Cbl modulates multiple critical properties of glioblastomas, including the ability to generate tumors in vivo

We discovered that glioblastoma (GBM) cells use Cool-1/β-pix to inhibit normal activation of the c-Cbl ubiquitin ligase via the redox/Fyn/c-Cbl pathway and that c-Cbl inhibition is critical for GBM cell function. Restoring normal c-Cbl activity by Cool-1 knockdown in vitro reduced GBM cell division, almost eliminated generation of adhesion-independent spheroids, reduced the representation of cells expressing antigens thought to identify tumor initiating cells (TICs), reduced levels of several proteins of critical importance in TIC function (such as Notch-1 and Sox2), and increased sensitivity to BCNU (carmustine) and temozolomide (TMZ). In vivo, Cool-1 knockdown greatly suppressed the ability of GBM cells to generate tumors, an outcome that was c-Cbl dependent. In contrast, Cool-1 knockdown did not reduce division or increase BCNU or TMZ sensitivity in primary glial progenitor cells and Cool-1/c-Cbl complexes were not found in normal brain tissue. Our studies provide the first evidence that Cool-1 may be critical in the biology of human tumors, that suppression of c-Cbl by Cool-1 may be critical for generation of at least a subset of GBMs and offer a novel target that appears to be selectively necessary for TIC function and modulates chemoresistance in GBM cells. Targeting such proteins that inhibit c-Cbl offers potentially attractive opportunities for therapeutic development.

Laser Tandem Mass Spectrometry in a Time of Flight Instrument

We present a new laser tandem mass spectrometry technique in a reflectron time of flight (TOF) instrument. A first pulsed laser performs the multiphoton ionization and the primary photodissociation. A newly designed ion source permits a high mass resolution in the space focus of the 12 cm long first linear TOF, where then the secondary excitation can take place. For high resolution applications the pure secondary or pure metastable mass spectrum of a preselected precursor ion can be recorded using a new reflectron scanning technique. It is also possible to obtain the whole secondary mass spectrum with one cycle using a new postacceleration method. Several techniques for ejection of interfering ions are shown. The features of our techniques are demonstrated at various primary fragments of benzene.

Cucurbitacin I blocks cerebrospinal fluid and platelet derived growth factor-BB stimulation of leptomeningeal and meningioma DNA synthesis

Background

Currently, there are no consistently effective chemotherapies for recurrent and inoperable meningiomas. Recently, cucurbitacin I (JSI-124), a naturally occurring tetracyclic triterpenoid compound used as folk medicines has been found to have cytoxic and anti-proliferative properties in several malignancies thru inhibition of activator of transcription (STAT3) activation. Previously, we have found STAT3 to be activated in meningiomas, particularly higher grade tumors.

Methods

Primary leptomeningeal cultures were established from 17, 20 and 22 week human fetuses and meningioma cell cultures were established from 6 World Health Organization (WHO) grade I or II meningiomas. Cells were treated with cerebrospinal fluid from patients without neurologic disease. The effects of cucurbitacin I on cerebrospinal fluid stimulation of meningioma cell DNA synthesis phosphorylation/activation of JAK1, STAT3, pMEK1/2, p44/42MAPK, Akt, mTOR, Rb and caspase 3 activation were analyzed in human leptomeningeal and meningioma cells.

Results

Cerebrospinal fluid significantly stimulated DNA synthesis in leptomeningeal cells. Co-administration of cucurbitacin I (250 nM) produces a significant blockade of this effect. Cucurbitacin I alone also produced a significant reduction in basal DNA synthesis. In grade I and II meningiomas, cerebrospinal fluid also significantly stimulated DNA synthesis. Co-administration of cucurbitacin I (250 nM) blocked this effect.

In the leptomeningeal cultures, cerebrospinal fluid stimulated STAT3 phosphorylation but not p44/42MAPK, Akt or mTOR. Cucurbitacin I had no effect on basal STAT3 phosphorylation but co-administration with cerebrospinal fluid blocked cerebrospinal fluid stimulation of STAT3 phosphorylation in each. In the grade I meningiomas, cerebrospinal fluid stimulated phosphorylation of STAT3 and decreased MEK1/2 and cucurbitacin I had no effect on basal STAT3, p44/42MAPK, Akt, JAK1, mTOR, or Rb phosphorylation. In the grade II meningiomas, cerebrospinal fluid stimulated STAT3 phosphorylation in all and reduced phosphorylation of MEK1/2 in all and p44/42MAPK in one. Cucurbitacin I had no effect on basal phosphorylation of STAT3 but reduced phorphorylated p44/42 MAPK in 2 grade II meningioma cells lines.

Conclusions

These studies raise the possibility that cucurbitacin I might have value as an adjunct chemotherapy. Additional studies are warranted to evaluate the effects of cucurbitacin I on meningiomas in vivo.

Transcriptional differences between normal and glioma-derived glial progenitor cells identify a core set of dysregulated genes

Glial progenitor cells (GPCs) are a potential source of malignant gliomas. We used A2B5-based sorting to extract tumorigenic GPCs from human gliomas spanning World Health Organization grades II-IV. Messenger RNA profiling identified a cohort of genes that distinguished A2B5+ glioma tumor progenitor cells (TPCs) from A2B5+ GPCs isolated from normal white matter. A core set of genes and pathways was substantially dysregulated in A2B5+ TPCs, which included the transcription factor SIX1 and its principal cofactors, EYA1 and DACH2. Small hairpin RNAi silencing of SIX1 inhibited the expansion of glioma TPCs in vitro and in vivo, suggesting a critical and unrecognized role of the SIX1-EYA1-DACH2 system in glioma genesis or progression. By comparing the expression patterns of glioma TPCs with those of normal GPCs, we have identified a discrete set of pathways by which glial tumorigenesis may be better understood and more specifically targeted.

Tophaceous pseudogout of the thoracic spine

Calcium pyrophosphate dihydrate deposition disease (CPDD, tophaceous pseudogout) is a rare crystal arthropathy characterized by pyrophosphate crystal deposition in joints, synovitis and chondrocalcinosis on imaging. We present the case of a 72-year-old man with 6 months of left chest pain; magnetic resonance imaging revealed a T9/T10 herniated disc. Intraoperatively, the material was sent for pathological analysis revealing pseudogout. Axial calcium pyrophosphate crystal deposition is rare but reported in the literature and found at the craniocervical junction and skull. Spinal calcium pyrophosphate crystal deposition is rare in the thoracic spine. It is often asymptompatic and can involve the disc or ligaments. This case demonstrates a unique presentation of CPDD.

Propionic acidemia: neonatal versus selective metabolic screening

BACKGROUND

Whereas propionic acidemia (PA) is a target disease of newborn screening (NBS) in many countries, it is not in others. Data on the benefit of NBS for PA are sparse.

STUDY DESIGN

Twenty PA patients diagnosed through NBS were compared to 35 patients diagnosed by selective metabolic screening (SMS) prompted by clinical findings, family history, or routine laboratory test results. Clinical and biochemical data of patients from 16 metabolic centers in Germany, Austria, and Switzerland were evaluated retrospectively. Additionally, assessment of the intelligent quotient (IQ) was performed. In a second step, the number of PA patients who have died within the past 20 years was estimated based on information provided by the participating metabolic centers.

RESULTS

Patients diagnosed through NBS had neither a milder clinical course regarding the number of metabolic crises nor a better neurological outcome. Among NBS patients, 63% were already symptomatic at the time of diagnosis, and <10% of all patients remained asymptomatic. Among all PA patients, 76% were found to be at least mildly mentally retarded, with an IQ <69. IQ was negatively correlated with the number of metabolic decompensations, but not simply with the patients' age. Physical development was also impaired in the majority of patients. Mortality rates tended to be lower in NBS patients compared with patients diagnosed by SMS.

CONCLUSION

Early diagnosis of PA through NBS seems to be associated with a lower mortality rate. However, no significant benefit could be shown for surviving patients with regard to their clinical course, including the number of metabolic crises, physical and neurocognitive development, and long-term complications.

Mutation analysis in 54 propionic acidemia patients

Deficiency of propionyl CoA carboxylase (PCC), a dodecamer of alpha and beta subunits, causes inherited propionic acidemia. We have studied, at the molecular level, PCC in 54 patients from 48 families comprised of 96 independent alleles. These patients of various ethnic backgrounds came from research centers and hospitals in Germany, Austria and Switzerland. The thorough clinical characterization of these patients was described in the accompanying paper (Grünert et al. 2012). In all 54 patients, many of whom originated from consanguineous families, the entire PCCB gene was examined by genomic DNA sequencing and in 39 individuals the PCCA gene was also studied. In three patients we found mutations in both PCC genes. In addition, in many patients RT-PCR analysis of lymphoblast RNA, lymphoblast enzyme assays, and expression of new mutations in E.coli were carried out. Eight new and eight previously detected mutations were identified in the PCCA gene while 15 new and 13 previously detected mutations were found in the PCCB gene. One missense mutation, p.V288I in the PCCB gene, when expressed in E.coli, yielded 134% of control activity and was consequently classified as a polymorphism in the coding region. Numerous new intronic polymorphisms in both PCC genes were identified. This study adds a considerable amount of new molecular data to the studies of this disease.

STATISTICAL INFORMATION CHARACTERIZATION OF CONSERVED NON-CODING ELEMENTS IN VERTEBRATES

Recently, a set of highly conserved non-coding elements (CNEs) has been derived from a comparison between the genomes of the puffer fish, Takifugu or Fugu rubripes, and man. In order to facilitate the identification of these conserved elements in silico, we characterize them by a number of statistical features.

We found a pronounced information pattern around CNE borders; although the CNEs themselves are AT rich and have high entropy (complexity), they are flanked by GC-rich regions of low entropy (complexity). We also identified the most abundant motifs within and around of CNEs, and identified those that group around their borders. Like in human promoter regions, the TBP, NF-Y and some other binding motifs are clustered around CNE boundaries, which may suggest a possible transcription regulatory function of CNEs.

Tumour epithelial vimentin expression and outcome of pancreatic ductal adenocarcinomas

PURPOSE

Tumour epithelial vimentin expression is a marker of mesenchymal differentiation and may be a useful marker of carcinomas with more aggressive behaviour. The aim of this study was to determine the extent and prognostic significance of vimentin expression in pancreatic ductal adenocarcinomas.

METHODS

Vimentin expression was detected by immunohistochemistry on tissue microarrays of surgically resected pancreatic ductal adenocarcinomas from 387 patients. The percentage of vimentin-immunolabelled neoplastic cells was correlated with outcome and with clinico-pathological factors using the Kaplan-Meier method and Cox multivariate survival models.

RESULTS

In all, 45% of primary pancreatic adenocarcinomas contained neoplastic cells that expressed vimentin, and in 27.5% of the cancers >10% of cells expressed vimentin. Vimentin expression was correlated with poor histological differentiation. By both uni- and multivariate survival analysis, neoplastic vimentin expression (P<0.01, HR 1.52, 95% confidence interval 1.14-2.04) was an indicator of a shorter postsurgical survival independent of other clinico-pathological variables.

CONCLUSION

The presence of vimentin-expressing tumour epithelial cells in surgically resected pancreatic adenocarcinomas independently predicted a shorter postsurgical survival.