Adrenergic and mesenchymal signatures are identifiable in cell-free DNA and correlate with metastatic disease burden in children with neuroblastoma

BACKGROUND

Cell-free DNA (cfDNA) profiles of 5-hydroxymethylcytosine (5-hmC), an epigenetic marker of open chromatin and active gene expression, are correlated with metastatic disease burden in patients with neuroblastoma. Neuroblastoma tumors are comprised of adrenergic (ADRN) and mesenchymal (MES) cells, and the relative abundance of each in tumor biopsies has prognostic implications. We hypothesized that ADRN and MES-specific signatures could be quantified in cfDNA 5-hmC profiles and would augment the detection of metastatic burden in patients with neuroblastoma.

METHODS

We previously performed an integrative analysis to identify ADRN and MES-specific genes (n = 373 and n = 159, respectively). Purified DNA from cell lines was serial diluted with healthy donor cfDNA. Using Gene Set Variation Analysis (GSVA), ADRN and MES signatures were optimized. We then quantified signature scores, and our prior neuroblastoma signature, in cfDNA from 84 samples from 46 high-risk patients including 21 patients with serial samples.

RESULTS

Samples from patients with higher metastatic burden had increased GSVA scores for both ADRN and MES gene signatures (p < .001). While ADRN and MES signature scores tracked together in serially collected samples, we identified instances of patients with increases in either MES or ADRN score at relapse.

CONCLUSIONS

While it is feasible to identify ADRN and MES signatures using 5-hmC profiles of cfDNA from neuroblastoma patients and correlate these signatures to metastatic burden, additional data are needed to determine the optimal strategies for clinical implementation. Prospective evaluation in larger cohorts is ongoing.

Intravenous cangrelor use for neuroendovascular procedures: a two-center experience and updated systematic review

Background

The optimal antiplatelet therapy regimen for certain neuroendovascular procedures remains unclear. This study investigates the safety and feasibility of intravenous dose-adjusted cangrelor in patients undergoing acute neuroendovascular interventions.

Methods

We conducted a retrospective chart review of all consecutive patients on intravenous cangrelor for neuroendovascular procedures between September 1, 2020, and March 13, 2022. We also conducted an updated systematic review and meta-analysis using PubMed, Scopus, Web of Science, Embase and the Cochrane Library up to February 22, 2023.

Results

In our cohort, a total of 76 patients were included [mean age (years): 57.2 ± 18.2, males: 39 (51.3), Black: 49 (64.5)]. Cangrelor was most used for embolization and intracranial stent placement (n = 24, 32%). Approximately 44% of our patients had a favorable outcome with a modified Rankin Scale (mRS) score of 0 to 2 at 90 days (n = 25/57); within 1 year, 8% of patients had recurrent or new strokes (n = 5/59), 6% had symptomatic intracranial hemorrhage [sICH] (4/64), 3% had major extracranial bleeding events (2/64), and 3% had a gastrointestinal bleed (2/64). In our meta-analysis, 11 studies with 298 patients were included. The pooled proportion of sICH and intraprocedural thromboembolic complication events were 0.07 [95% CI 0.04 to 1.13] and 0.08 [95% CI 0.05 to 0.15], respectively.

Conclusion

Our study found that intravenous cangrelor appears to be safe and effective in neuroendovascular procedures, with low rates of bleeding and ischemic events. However, further research is needed to compare different dosing and titration protocols of cangrelor and other intravenous agents.

Adapting a Medical School Cancer Research Education Program to the Virtual Environment: a Mixed-Methods Study

With cancer incidence increasing worldwide, physicians with cancer research training are needed. The Scholars in Oncology-Associated Research (SOAR) cancer research education program was developed to train medical students in cancer research while exposing them to the breadth of clinical oncology. Due to the COVID-19 pandemic, SOAR transitioned from in-person in 2019 to virtual in 2020 and hybrid in 2021. This study investigates positive and negative aspects of the varying educational formats. A mixed-methods approach was used to evaluate the educational formats. Pre- and post-surveys were collected from participants to assess their understanding of cancer as a clinical and research discipline. Structured interviews were conducted across all three cohorts, and thematic analysis was used to generate themes. A total of 37 students participated in SOAR and completed surveys (2019 n = 11, 2020 n = 14, and 2021 n = 12), and 18 interviews were conducted. Understanding of oncology as a clinical (p < 0.01 for all) and research discipline (p < 0.01 for all) improved within all three cohorts. There was no difference between each cohort's improvement in research understanding (p = 0.6). There was no difference between each cohort's understanding of oncology-related disciplines as both clinical and research disciplines (p > 0.1 for all). Thematic analysis demonstrated that hybrid and in-person formats were favored over a completely virtual one. Our findings demonstrate that a medical student cancer research education program is effective using in-person or hybrid formats for research education, although virtual experiences may be suboptimal to learning about clinical oncology.

Adrenergic and mesenchymal signatures are identifiable in cell-free DNA and correlate with metastatic disease burden in children with neuroblastoma

Background

Cell free DNA (cfDNA) profiles of 5-hydroxymethylcytosine (5-hmC), an epigenetic marker of open chromatin and active gene expression, are correlated with metastatic disease burden in patients with neuroblastoma. Neuroblastoma tumors are comprised of adrenergic (ADRN) and mesenchymal (MES) cells, and the relative abundance of each in tumor biopsies has prognostic implications. We hypothesized that ADRN and MES specific signatures could be quantified in cfDNA 5-hmC profiles and would augment the detection of metastatic burden in patients with neuroblastoma.

Methods

We previously performed an integrative analysis to identify ADRN and MES specific genes (n=373 and n=159, respectively). Purified DNA from cell lines was serial diluted with healthy donor cfDNA. Using Gene Set Variation Analysis (GSVA), ADRN and MES signatures were optimized. We then quantified signature scores, and our prior neuroblastoma signature, in cfDNA from 84 samples from 46 high-risk patients including 21 patients with serial samples.

Results

Samples from patients with higher metastatic burden had increased GSVA scores for both ADRN and MES gene signatures (p < 0.001). While ADRN and MES signature scores tracked together in serially collected samples, we identified instances of patients with increases in either MES or ADRN score at relapse.

Conclusions

While it is feasible to identify ADRN and MES signatures using 5-hmC profiles of cfDNA from neuroblastoma patients and correlate these signatures to metastatic burden, additional data are needed to determine the optimal strategies for clinical implementation. Prospective evaluation in larger cohorts is ongoing.

T-cell inflammation is prognostic of survival in patients with high-risk neuroblastoma enriched for an adrenergic signature

Purpose

T-cell inflammation (TCI) has been shown to be a prognostic marker in neuroblastoma, a tumor comprised of cells that can exist in two epigenetic states, adrenergic (ADRN) and mesenchymal (MES). We hypothesized that elucidating unique and overlapping aspects of these biologic features could serve as novel biomarkers.

Patients and Methods

We detected lineage-specific, single-stranded super-enhancers defining ADRN and MES specific genes. Publicly available neuroblastoma RNA-seq data from GSE49711 (Cohort 1) and TARGET (Cohort 2) were assigned MES, ADRN, and TCI scores. Tumors were characterized as MES (top 33%) or ADRN (bottom 33%), and TCI (top 67% TCI score) or non-inflamed (bottom 33% TCI score). Overall survival (OS) was assessed using the Kaplan-Meier method, and differences were assessed by the log-rank test.

Results

We identified 159 MES genes and 373 ADRN genes. TCI scores were correlated with MES scores (R=0.56, p<0.001 and R=0.38, p<0.001) and anticorrelated with MYCN -amplification (R=-0.29, p<0.001 and -0.18, p=0.03) in both cohorts. Among Cohort 1 patients with high-risk, ADRN tumors (n=59), those with TCI tumors (n=22) had superior OS to those with non-inflammed tumors (n=37) (p=0.01), though this comparison did not reach significance in Cohort 2. TCI status was not associated with survival in patients with high-risk MES tumors in either cohort.

Conclusions

High inflammation scores were correlated with improved survival in some high-risk patients with, ADRN but not MES neuroblastoma. These findings have implications for approaches to treating high-risk neuroblastoma.

Using a Nationwide Virtual Radiology Student Interest Group to Expand Medical Students' General Awareness, Drive Greater Interest, and Achieve Uniform National Messaging in the Field of Radiology

RATIONALE AND OBJECTIVES

Many medical schools offer minimal exposure to radiology, leading to a decreased understanding of the field and negative perceptions among medical students. The purpose of this study was to examine the effects of a radiology intensive series piloted by a novel virtual radiology interest group. Specifically, we were interested in how radiologists and medical educators can expand students' general awareness, drive greater interest in the field, and achieve more uniform national messaging across all trainees.

MATERIALS AND METHODS

We launched a national/international interest group called Radiology Student Interest Group (RadSIG) and piloted the RadSIG Intensive, a series of five events aimed at increasing awareness and dispelling misconceptions among preclinical medical students. Validated pre-intensive and post-intensive surveys were used to ascertain the students' baseline and changed perspectives, respectively. A separate faculty survey was also distributed to understand how they perceived our events. Statistical analysis was carried out on the collected data to identify trends and assess the utility of our programming.

RESULTS

205 students completed the pre-intensive survey, and 61 students completed the post-intensive survey. Of the pre-intensive survey respondents, 51.7% (106/205) indicated that they had a limited understanding of what a career in radiology entails. Of those who completed the entire RadSIG Intensive, average 5-point Likert scale scores for understanding of a radiology career rose from 3.30 to 4.38 respectively pre- to post-completion. A Wilcoxon signed-rank test revealed that this difference was statistically significant (Z=-5.95, p<0.001), and that the RadSIG Intensive significantly improved perceptions of radiologists across every single question measured, except for perception of long hours worked (Z=-0.20, p=0.841). The results also showed increased student comfort in reaching out to radiology attendings (Z=-4.30, p<0.001) and residents (Z=-5.12, p<0.001). Faculty survey results indicated positive perceptions of the series.

CONCLUSION

Our results show that the RadSIG Intensive was effective in increasing students' understanding of radiology as a field and a potential career. Online outreach can also lower the resistance and improve student comfort in reaching out for mentorship, which may provide a new pathway to reach underserved students with a unifying message. By furthering a platform based on voluntary and supplemental resources, we see a far greater potential of impacting the perception and known role of the imager in patient care among our next generation of physicians.

Endovascular thrombectomy and repair of suprarenal inferior vena cava thrombosis: A case series

OBJECTIVES

The objective of this study is to document the combined use of catheter-based thrombectomy/thrombolysis with endovascular repair of high-risk segments of the inferior vena cava in the setting of iatrogenic and traumatic injuries. While the use of endovascular techniques to treat caval thrombosis is well documented and often preferred due to its minimally invasive nature, there is still little literature that focuses on the nuances related to injury of high mortality areas of the IVC as a result of major trauma, transplant, and other surgical interventions.

METHODS

An IRB-approved retrospective review of all patients undergoing IVC thrombectomy was performed at a single tertiary care academic center between January 2018 and July 2021. Cases were subsequently selected based on those who underwent primary mechanical thrombectomy followed by endovascular stenting (or angioplasty). Among this cohort, four patients who underwent this procedure in the context of iatrogenic and traumatic injuries were included.

RESULTS

All four patients undergoing primary mechanical thrombectomy followed by endovascular stenting (or angioplasty) due to IVC thrombus and/or stenosis were technically successful with immediate positive clinical outcomes.

CONCLUSIONS

Mechanical thrombectomy in conjunction with IVC recanalization via stenting may be a useful intervention with promising technical success and positive clinical outcomes for occlusive thrombosis and IVC stenosis.