Liquid biopsy-based circulating tumour (ct)DNA analysis of a spectrum of myeloid and lymphoid malignancies yields clinically actionable results

AIMS

Liquid biopsy (LBx)-based next-generation sequencing (NGS) of circulating tumour DNA (ctDNA) can facilitate molecular profiling of haematopoietic neoplasms (HNs), particularly when tissue-based NGS is infeasible.

METHODS AND RESULTS

We studied HN LBx samples tested with FoundationOne Liquid CDx, FoundationOne Liquid, or FoundationACT between July 2016 and March 2022. We identified 271 samples: 89 non-Hodgkin lymphoma (NHL), 43 plasma-cell neoplasm (PCN), 41 histiocytoses, 27 myelodysplastic syndrome (MDS), 25 diffuse large B-cell lymphoma (DLBCL), 22 myeloproliferative neoplasm (MPN), 14 Hodgkin lymphoma (HL), and 10 acute myeloid leukaemia (AML). Among 73.4% with detectable pathogenic alterations, median maximum somatic allele frequency (MSAF) was 16.6%, with AML (36.2%), MDS (19.7%), and MPN (44.5%) having higher MSAFs than DLBCL (3.9%), NHL (8.4%), HL (1.5%), PCN (2.8%), and histiocytoses (1.8%) (P = 0.001). LBx detected characteristic alterations across HNs, including in TP53, KRAS, MYD88, and BTK in NHLs; TP53, KRAS, NRAS, and BRAF in PCNs; IGH in DLBCL; TP53, ATM, and PDCD1LG2 in HL; BRAF and MAP2K1 in histiocytoses; TP53, SF3B1, DNMT3A, TET2, and ASXL1 in MDS; JAK2 in MPNs; and FLT3, IDH2, and NPM1 in AML. Among 24 samples, the positive percent agreement by LBx was 75.7% for variants present in paired buffy coat, marrow, or tissues. Also, 75.0% of pairs exhibited alterations only present on LBx. These were predominantly subclonal (clonal fraction of 3.8%), reflecting the analytical sensitivity of LBx.

CONCLUSION

These data demonstrate that LBx can detect relevant genomic alterations across HNs, including at low clonal fractions, suggesting a potential clinical utility for identifying residual or emerging therapy-resistant clones that may be undetectable in site-specific tissue biopsies.

Biomechanical comparison of bone staple fixation methods with suture material for median sternotomy closure using 3D-printed bone models

AIM

To compare the biomechanical properties of three different sternal closure techniques in a 3D-printed bone model of a sternum from a 30-kg dog.

METHODS

Median sternotomy was performed on a total of 90 three-dimensional (3D) copies of a polycarbonate (PC) model of a sternum, generated from the CT images of the sternum of a 30-kg German Shepherd dog. Three different methods were used to repair the sternotomies: polydioxanone suture (group PDS, n = 30), stainless steel bone staples (group SS, n = 30), and nitinol bone staples (group NS, n = 30). Each repair method was tested by applying tensile force in one of three ways (longitudinally, laterally, or torsionally) resulting in a sample size of n = 10 for each repair method-loading combination. In all experiments, the loads at 1-mm and 2-mm gap formation, failure, and the displacement at the failure point were measured.

RESULTS

In lateral distraction and longitudinal shear tests, NS and SS staple repairs required application of significantly greater force than PDS across all displacement criteria (1 and 2 mm). NS exhibited significantly greater failure load than PDS. In torsion tests, NS required significantly greater application of force compared to SS or PDS at all displacement criteria (1 and 2 mm) and exhibited a greater failure load than PDS. In terms of displacement at failure point, PDS suture showed more displacement than SS or NS across all experiments (laterally, longitudinally, torsionally).

CONCLUSIONS

In this study, bone staples were mechanically superior to PDS suture in median sternotomy closure using 3D-printed bone model in terms of 1-mm, 2-mm displacement loads, and displacement at failure. NS had a higher failure load than PDS under lateral, longitudinal, and torsional distraction.

CLINICAL RELEVANCE

These study results imply that bone staples can be considered as an alternative surgical method for median sternotomy closure in dogs.

Comparing hospital vs. non-hospital-affiliated clinic adoption of abortion innovations and cash-pay availability during the COVID-19 pandemic: A secondary analysis of a United States nationwide survey

OBJECTIVES

We examined differences between hospital-affiliated clinics and non-hospital-affiliated clinics (independent or Planned Parenthood clinics) regarding abortion service innovation and cash-pay availability in response to COVID-19.

STUDY DESIGN

We analyzed data from all three phases of a longitudinal nationwide survey of abortion providers conducted by the Society of Family Planning.

RESULTS

This study utilizes a convenience sample of 74 voluntarily participating clinics, representing 5% of clinics nationwide. Compared to non-hospital-affiliated clinics, hospital-affiliated clinics were more likely to initiate care innovations but were less likely to offer cash-pay during the pandemic.

CONCLUSIONS

Both hospital-affiliated and non-hospital-affiliated clinics enacted patient-centered care innovations during the pandemic. Hospital-affiliated clinics were more likely to initiate innovative services, particularly surrounding telemedicine. Hospital-affiliated clinics can improve cash-pay availability to expand access to abortion care in times of national emergencies.

RAS/RAF Comutation and ERBB2 Copy Number Modulates HER2 Heterogeneity and Responsiveness to HER2-directed Therapy in Colorectal Cancer

PURPOSE

ERBB2-amplified colorectal cancer is a distinct molecular subtype with expanding treatments. Implications of concurrent oncogenic RAS/RAF alterations are not known.

EXPERIMENTAL DESIGN

Dana-Farber and Foundation Medicine Inc. Colorectal cancer cohorts with genomic profiling were used to identify ERBB2-amplified cases [Dana-Farber, n = 47/2,729 (1.7%); FMI, n = 1857/49,839 (3.7%)]. Outcomes of patients receiving HER2-directed therapies are reported (Dana-Farber, n = 9; Flatiron Health-Foundation Medicine clinicogenomic database, FH-FMI CGDB, n = 38). Multisite HER2 IHC and genomic profiling were performed to understand HER2 intratumoral and interlesional heterogeneity. The impact of concurrent RAS comutations on the effectiveness of HER2-directed therapies were studied in isogenic colorectal cancer cell lines and xenografts.

RESULTS

ERBB2 amplifications are enriched in left-sided colorectal cancer. Twenty percent of ERBB2-amplified colorectal cancers have co-occurring oncogenic RAS/RAF alterations. While RAS/RAF WT colorectal cancers typically have clonal ERBB2 amplification, colorectal cancers with co-occurring RAS/RAF alterations have lower level ERRB2 amplification, higher intratumoral heterogeneity, and interlesional ERBB2 discordance. These distinct genomic patterns lead to differential responsiveness and patterns of resistance to HER2-directed therapy. ERBB2-amplified colorectal cancer with RAS/RAF alterations are resistant to trastuzumab-based combinations, such as trastuzumab/tucatinib, but retain sensitivity to trastuzumab deruxtecan in in vitro and murine models. Trastuzumab deruxtecan shows clinical efficacy in cases with high-level ERBB2-amplified RAS/RAF coaltered colorectal cancer.

CONCLUSIONS

Co-occurring RAS/RAF alterations define a unique subtype of ERBB2-amplified colorectal cancer that has increased intratumoral heterogeneity, interlesional discordance, and resistance to trastuzumab-based combinations. Further examination of trastuzumab deruxtecan in this previously understudied cohort of ERBB2-amplified colorectal cancer is warranted.

Activating point mutations in the MET kinase domain represent a unique molecular subset of lung cancer and other malignancies targetable with MET inhibitors

Activating point mutations in the MET tyrosine kinase domain (TKD) are oncogenic in a subset of papillary renal cell carcinomas (PRCC). Here, using comprehensive genomic profiling among >600,000 patients, we identify activating MET TKD point mutations as putative oncogenic driver across diverse cancers, with a frequency of ~0.5%. The most common mutations in the MET TKD defined as oncogenic or likely oncogenic according to OncoKB resulted in amino acid substitutions at positions H1094, L1195, F1200, D1228, Y1230, M1250, and others. Preclinical modeling of these alterations confirmed their oncogenic potential, and also demonstrated differential patterns of sensitivity to type I and type II MET inhibitors. Two patients with metastatic lung adenocarcinoma harboring MET TKD mutations (H1094Y, F1200I) and no other known oncogenic drivers achieved confirmed partial responses to a type I MET inhibitor. Activating MET TKD mutations occur in multiple malignancies and may confer clinical sensitivity to currently available MET inhibitors.

Association of Timely Comprehensive Genomic Profiling With Precision Oncology Treatment Use and Patient Outcomes in Advanced Non-Small-Cell Lung Cancer

PURPOSE

Timely biomarker testing remains out of reach for many patients with advanced non-small-cell lung cancer (aNSCLC). Here, we studied the quality-of-care implications of closing the gap in timely receipt of comprehensive genomic profiling (CGP) to inform first-line (1L) decisions.

METHODS

Using a real-world clinicogenomic database, we studied testing and 1L treatment patterns in aNSCLC after the approval of pembrolizumab in combination with pemetrexed and carboplatin (May 10, 2017). To estimate the association of timely CGP results with therapy selection and patient outcomes, we identified patients with no previous genomic testing beyond PD-L1 immunohistochemistry and dichotomized patients by whether CGP results were available before or after 1L therapy initiation.

RESULTS

In total, 2,694 patients were included in the 1L therapy decision impact assessment. Timely CGP increased matched targeted therapy use by 14 percentage points (17% with CGP v 2.8% without) and precision immune checkpoint inhibitor (ICPI) use by 14 percentage points (18% with CGP v 3.9% without). Receipt of timely CGP resulted in an estimated 31 percentage point decrease in ICPI use among ALK/EGFR/RET/ROS1-positive patients at an expected per-patient reduction in ineffective ICPI therapy cost of $13,659.37 with timely CGP to inform 1L treatment selection. Patient benefit of CGP extended to real-world time to therapy discontinuation (median time to therapy discontinuation: 3.9 v 10 months [hazard ratio, HR, 0.54 [95% CI, 0.42 to 0.70]; P = 1.9E-06; adjusted hazard ratio [aHR], 0.50 [95% CI, 0.38 to 0.67]; P = 2.0E-06) in 1L driver-positive patients. This effect was not significant for real-world overall survival (median overall survival: 32 v 29 months [HR, 1.2 [95% CI, 0.84 to 1.67]; P = .33; aHR, 1.4 [95% CI, 0.92 to 1.99]; P = .12).

CONCLUSION

Timely CGP is associated with the quality of patient care as measured by 1L matched targeted therapy use, time to therapy discontinuation, and avoidance of ineffective, costly ICPIs.

Dynamic changes in perivascular space morphology predict signs of spaceflight-associated neuro-ocular syndrome in bed rest

During long-duration spaceflight, astronauts experience headward fluid shifts and expansion of the cerebral perivascular spaces (PVS). A major limitation to our understanding of the changes in brain structure and physiology induced by spaceflight stems from the logistical difficulties of studying astronauts. The current study aimed to determine whether PVS changes also occur on Earth with the spaceflight analog head-down tilt bed rest (HDBR). We examined how the number and morphology of magnetic resonance imaging-visible PVS (MV-PVS) are affected by HDBR with and without elevated carbon dioxide (CO2). These environments mimic the headward fluid shifts, body unloading, and elevated CO2 observed aboard the International Space Station. Additionally, we sought to understand how changes in MV-PVS are associated with signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), ocular structural alterations that can occur with spaceflight. Participants were separated into two bed rest campaigns: HDBR (60 days) and HDBR + CO2 (30 days with elevated ambient CO2). Both groups completed multiple magnetic resonance image acquisitions before, during, and post-bed rest. We found that at the group level, neither spaceflight analog affected MV-PVS quantity or morphology. However, when taking into account SANS status, persons exhibiting signs of SANS showed little or no MV-PVS changes, whereas their No-SANS counterparts showed MV-PVS morphological changes during the HDBR + CO2 campaign. These findings highlight spaceflight analogs as models for inducing changes in MV-PVS and implicate MV-PVS dynamic compliance as a mechanism underlying SANS. These findings may lead to countermeasures to mitigate health risks associated with human spaceflight.

Circulating Tumor DNA Enables Sensitive Detection of Actionable Gene Fusions and Rearrangements Across Cancer Types

PURPOSE

Genomic rearrangements can generate potent oncogenic drivers or disrupt tumor suppressor genes. This study examines the landscape of fusions and rearrangements detected by liquid biopsy (LBx) of circulating tumor DNA (ctDNA) across different cancer types.

EXPERIMENTAL DESIGN

LBx from 53,842 patients with 66 solid tumor types were profiled using FoundationOneLiquid CDx, a hybrid-capture sequencing platform that queries 324 cancer-related genes. Tissue biopsies (TBx) profiled using FoundationOneCDx were used as a comparator.

RESULTS

Among all LBx, 7,377 (14%) had ≥1 pathogenic rearrangement detected. A total of 3,648 (6.8%) LBx had ≥1 gain-of-function (GOF) oncogene rearrangement, and 4,428 (8.2%) LBx had ≥1 loss-of-function rearrangement detected. Cancer types with higher prevalence of GOF rearrangements included those with canonical fusion drivers: prostate cancer (19%), cholangiocarcinoma (6.4%), bladder (5.5%), and non-small cell lung cancer (4.4%). Although the prevalence of driver rearrangements was lower in LBx than TBx overall, the frequency of detection was comparable in LBx with a tumor fraction (TF) ≥1%. Rearrangements in FGFR2, BRAF, RET, and ALK, were detected across cancer types, but tended to be clonal variants in some cancer types and potential acquired resistance variants in others.

CONCLUSIONS

In contrast to some prior literature, this study reports detection of a wide variety of rearrangements in ctDNA. The prevalence of driver rearrangements in tissue and LBx was comparable when TF ≥1%. LBx presents a viable alternative when TBx is not available, and there may be less value in confirmatory testing when TF is sufficient.

Neural correlates of drinking reduction during a clinical trial of cognitive behavioral therapy for alcohol use disorder

BACKGROUND

Cognitive behavioral therapy (CBT) is an effective treatment for alcohol use disorder (AUD). We hypothesized that the dorsolateral prefrontal cortex (DLPFC), a region implicated in cognitive control and goal-directed behavior, plays a role in behavior change during CBT by facilitating the regulation of craving (ROC).

METHODS

Treatment-seeking participants with AUD (N = 22) underwent functional magnetic resonance imaging (fMRI) scanning both before and after a 12-week, single-arm trial of CBT, using an ROC task that was previously shown to engage the DLPFC.

RESULTS

We found that both the percentage of heavy drinking days (PHDD) and the overall self-reported alcohol craving measured during the ROC task were significantly reduced from pre- to post-CBT. However, we did not find significant changes over time in either the ability to regulate craving or regulation-related activity in any brain region. We found a significant 3-way interaction between the effects of cue-induced craving, cue-induced brain activity and timepoint of assessment (pre- or post-CBT) on PHDD in the left DLPFC. Follow-up analysis showed that cue-induced craving was associated with cue-induced activity in the left DLPFC among participants who ceased heavy drinking during CBT, both at pre-CBT and post-CBT timepoints. No such associations were present at either timepoint among participants who continued to drink heavily.

CONCLUSIONS

These results suggest that patients in whom DLPFC functioning is more strongly related to cue-induced craving may preferentially respond to CBT.

Real-World Genomic Profile of EGFR Second-Site Mutations and Other Osimertinib Resistance Mechanisms and Clinical Landscape of NSCLC Post-Osimertinib

INTRODUCTION

The emergence of osimertinib as standard of care for EGFR-mutant NSCLC has renewed the need to understand and overcome drug resistance. We sought to understand the genomics and real-world treatment landscape of NSCLC with EGFR C797S and other on- and off-target resistance mechanisms.

METHODS

Comprehensive genomic profiling (CGP) results from tissue or blood samples from 93,065 patients with NSCLC were queried for osimertinib EGFR second-site resistance mutations (ssEGFRms; C797, L718, G724, G796, L792). A real-world electronic health record-derived deidentified clinicogenomic database of patients with NSCLC undergoing CGP from approximately 280 U.S. cancer clinics was queried to assess post-osimertinib resistance and clinical treatment outcomes.

RESULTS

A ssEGFRm was identified in 239 of 8845 (2.7%) EGFR-driven (L858R or exon 19 deletion) NSCLCs, most frequently C797 (71%), L718 (15%), and G724 (9.5%). ssEGFRms were not equally distributed across drivers; C797 and G724 changes strongly favored exon 19 deletion and L718, G796 and L792 favored L858R. Post-osimertinib CGP detected ssEGFRm in 19% of the cases (39 of 205); in paired pre-/post-osimertinib samples, on- and off-target resistance was largely mutually exclusive and observed in 24% and 27% of the cases, respectively. Of 391 patients with post-osimertinib treatment data, 62% received a chemotherapy-based regimen, whereas 25% received a targeted therapy or clinical study drug. Median real-world overall survival was 11.4 months from osimertinib progression.

CONCLUSIONS

The osimertinib resistance landscape is diverse with on-target ssEGFRm and off-target resistance detected in tissue and liquid biopsy. Post-osimertinib, patients are receiving primarily chemotherapy-based regimens with poor outcomes, and CGP at resistance may offer an opportunity to inform therapeutic development and improve treatment selection.

Liquid Biopsy of Lung Cancer Before Pathological Diagnosis Is Associated With Shorter Time to Treatment

PURPOSE

Studies have investigated the early use of liquid biopsy (LBx) during the diagnostic workup of patients presenting with clinical evidence of advanced lung cancer, but real-world adoption and impact has not been characterized. The aim of this study was to determine whether the use of LBx before diagnosis (Dx; LBx-Dx) enables timely comprehensive genomic profiling (CGP) and shortens time until treatment initiation for advanced non-small-cell lung cancer (aNSCLC).

MATERIALS AND METHODS

This study used the Flatiron Health-Foundation Medicine electronic health record-derived deidentified clinicogenomic database of patients with aNSCLC from approximately 280 US cancer clinics.

RESULTS

Of 1,076 patients with LBx CGP ordered within 30 days prediagnosis/postdiagnosis, we focused on 56 (5.2%) patients who ordered LBx before diagnosis date (median 8 days between order and diagnosis, range, 1-28). Compared with 1,020 patients who ordered LBx after diagnosis (Dx-LBx), LBx-Dx patients had similar stage and ctDNA tumor fraction (TF). LBx-Dx patients received CGP results a median of 1 day after Dx versus 25 days for Dx-LBx patients. Forty-three percent of LBx-Dx were positive for an National Comprehensive Cancer Network driver, and 32% had ctDNA TF >1% but were driver negative (presumed true negatives). In 748 patients with previously untreated aNSCLC, median time from Dx to therapy was shorter in the LBx-Dx versus Dx-LBx group (21 v 35 days; P < .001).

CONCLUSION

Early LBx in anticipation of pathologic diagnosis of aNSCLC was uncommon in this real-world cohort, yet this emerging paradigm was associated with an abbreviated time to CGP results and faster therapy initiation. Forthcoming prospective studies will clarify the utility of LBx in parallel with biopsy for diagnostic confirmation for patients presenting with suspected advanced lung cancer.

Reproductive justice advocacy efforts among genetic counselors and family planning providers

Throughout all areas of medical practice, genetic counselors (GCs) occupy a key position in promoting patients' personal autonomy while facilitating informed medical decision-making. This professional position aligns with the concept of reproductive justice. Previous literature has attempted to define reproductive advocacy in medicine as well as the potential intersection of genetic counseling and reproductive justice advocacy work, yet limited data exist regarding GCs' perceptions of their role and involvement in reproductive justice advocacy work. This study aimed to identify the perceptions and actions of GCs regarding reproductive justice advocacy measures, as well as explore motivating factors influencing their attitudes and behaviors. Family planning providers, who tend to prioritize reproductive justice and advocacy, were surveyed to be a comparison group. We distributed an anonymous online survey within the National Society of Genetic Counselors (NSGC) and the Society of Family Planning (SFP) consisting of a 10-item personality inventory and Likert scale questions exploring characteristics and behaviors regarding reproductive justice advocacy. Results from 252 eligible respondents were analyzed using descriptive statistics, Chi-square, and Mann-Whitney U analyses. NSGC members are significantly less involved in several areas of reproductive justice advocacy, including regular participation in advocacy efforts when compared to SFP members (p = 0.04). The most cited barrier to NSGC members' participation was feeling unsure how to become involved, a significant difference compared to SFP members (p = 0.01). Findings from this study, undertaken in the final days of Roe v. Wade, suggest that GCs want to be more involved in reproductive justice advocacy but are uncertain where to begin. Intersociety collaboration and intra-society promotion of grassroots reproductive justice efforts may reduce this perceived barrier and others like it.

Artificial gravity during a spaceflight analog alters brain sensory connectivity

Spaceflight has numerous untoward effects on human physiology. Various countermeasures are under investigation including artificial gravity (AG). Here, we investigated whether AG alters resting-state brain functional connectivity changes during head-down tilt bed rest (HDBR), a spaceflight analog. Participants underwent 60 days of HDBR. Two groups received daily AG administered either continuously (cAG) or intermittently (iAG). A control group received no AG. We assessed resting-state functional connectivity before, during, and after HDBR. We also measured balance and mobility changes from pre- to post-HDBR. We examined how functional connectivity changes throughout HDBR and whether AG is associated with differential effects. We found differential connectivity changes by group between posterior parietal cortex and multiple somatosensory regions. The control group exhibited increased functional connectivity between these regions throughout HDBR whereas the cAG group showed decreased functional connectivity. This finding suggests that AG alters somatosensory reweighting during HDBR. We also observed brain-behavioral correlations that differed significantly by group. Control group participants who showed increased connectivity between the putamen and somatosensory cortex exhibited greater mobility declines post-HDBR. For the cAG group, increased connectivity between these regions was associated with little to no mobility declines post-HDBR. This suggests that when somatosensory stimulation is provided via AG, functional connectivity increases between the putamen and somatosensory cortex are compensatory in nature, resulting in reduced mobility declines. Given these findings, AG may be an effective countermeasure for the reduced somatosensory stimulation that occurs in both microgravity and HDBR.

Fracture Liaison Service and Its Role in Secondary Fracture Prevention in Malaysia: A Scoping Review

Introduction

Fragility fractures, which occur after a low-trauma injury, increases with advancing age. Such fracture doubles the life-time risk of sustaining another fracture. This risk is highest in the immediate 18 months after the index fracture. However, most patients do not receive the appropriate risk assessment and intervention to reduce this risk. A coordinated model of care termed Fracture Liaison Service (FLS) has been reported to address this treatment gap.

Materials and methods

This scoping review aims to explore the potential role and delivery of FLS services in Malaysia. Scientific and non-scientific sources relevant to FLS were identified from electronic bibliographic databases, specialist journals and relevant websites. Findings were categorised into themes and presented narratively.

Results

FLS services remain concentrated in the Klang Valley. Even within FLS services, many do not have extensive coverage to risk assess all fracture patients. These services are multidisciplinary in nature where there are links between different departments, such as orthopaedics, osteoporosis expertise, bone densitometry, rehabilitation, falls services and primary care. FLS was able to increase the number of people undergoing fracture risk assessment and treatment. The importance of FLS was highlighted by local experts and stakeholders. Its implementation and delivery are supported by a number of national guidelines.

Conclusion

FLS is central to our national efforts to reduce the impending fragility fracture crisis in the coming years. Continued effort is needed to increase coverage within FLS services and across the country. Training, awareness of the problem, research, and policy change will support this endeavour.

The Road Not Taken: Disconnection of a Human-Unique Cortical Pathway Underlying Naturalistic Social Perception in Schizophrenia

Background

Efficient processing of complex and dynamic social scenes relies on intact connectivity of many underlying cortical areas and networks, but how connectivity anomalies affect the neural substrates of social perception remains unknown. Here we measured these relationships using functionally based localization of social perception areas, resting-state functional connectivity, and movie-watching data.

Methods

In 42 participants with schizophrenia (SzPs) and 41 healthy control subjects, we measured the functional connectivity of areas localized by face-emotion processing, theory-of-mind (ToM), and attention tasks. We quantified the weighted shortest path length between visual and medial prefrontal ToM areas in both populations to assess the impact of these changes in functional connectivity on network structure. We then correlated connectivity along the shortest path in each group with movie-evoked activity in a key node of the ToM network (posterior temporoparietal junction [TPJp]).

Results

SzPs had pronounced decreases in connectivity in TPJ/posterior superior temporal sulcus (TPJ-pSTS) areas involved in face-emotion processing (t81 = 4.4, p = .00002). In healthy control subjects, the shortest path connecting visual and medial prefrontal ToM areas passed through TPJ-pSTS, whereas in SzPs, the shortest path passed through the prefrontal cortex. While movie-evoked TPJp activity correlated with connectivity along the TPJ-pSTS pathway in both groups (r = 0.43, p = .002), it additionally correlated with connectivity along the prefrontal cortex pathway only in SzPs (rSzP = 0.56, p = .003).

Conclusions

These results suggest that connectivity along the human-unique TPJ-pSTS pathway affects both the network architecture and functioning of areas involved in processing complex dynamic social scenes. These results demonstrate how focal connectivity anomalies can have widespread impacts across the cortex.

Comprehensive genomic profiling and treatment patterns across ancestries in advanced prostate cancer: a large-scale retrospective analysis

BACKGROUND

Men of African ancestry experience the greatest burden of prostate cancer globally, but they are under-represented in genomic and precision medicine studies. Therefore, we sought to characterise the genomic landscape, comprehensive genomic profiling (CGP) utilisation patterns, and treatment patterns across ancestries in a large, diverse, advanced prostate cancer cohort, to determine the impact of genomics on ancestral disparities.

METHODS

In this large-scale retrospective analysis, the CGP-based genomic landscape was evaluated in biopsy sections from 11 741 patients with prostate cancer, with ancestry inferred using a single nucleotide polymorphism-based approach. Admixture-derived ancestry fractions for each patient were also interrogated. Independently, clinical and treatment information was retrospectively reviewed for 1234 patients in a de-identified US-based clinicogenomic database. Prevalence of gene alterations, including actionable gene alterations, was assessed across ancestries (n=11 741). Furthermore, real-world treatment patterns and overall survival was assessed in the subset of patients with linked clincogenomic information (n=1234).

FINDINGS

The CGP cohort included 1422 (12%) men of African ancestry and 9244 (79%) men of European ancestry; the clinicogenomic database cohort included 130 (11%) men of African ancestry and 1017 (82%) men of European ancestry. Men of African ancestry received more lines of therapy before CGP than men of European ancestry (median of two lines [IQR 0-8] vs one line [0-10], p=0·029). In genomic analyses, ancestry-specific mutational landscapes were observed, but the prevalence of alterations in AR, the DNA damage response pathway, and other actionable genes were similar across ancestries. Similar genomic landscapes were observed in analyses that accounted for admixture-derived ancestry fractions. After undergoing CGP, men of African ancestry were less likely to receive a clinical study drug compared with men of European ancestry (12 [10%] of 118 vs 246 [26%] of 938, p=0·0005).

INTERPRETATION

Similar rates of gene alterations with therapy implications suggest that differences in actionable genes (including AR and DNA damage response pathway genes) might not be a main driver of disparities across ancestries in advanced prostate cancer. Later CGP utilisation and a lower rate of clinical trial enrolment observed in men of African ancestry could affect genomics, outcomes, and disparities.

FUNDING

American Society for Radiation Oncology, Department of Defense, Flatiron Health, Foundation Medicine, Prostate Cancer Foundation, and Sylvester Comprehensive Cancer Center.

Abstract 3488: Truncated FGFR2 - a clinically actionable oncogene in multiple cancers

Human cancers frequently bear driver alterations in genes encoding receptor tyrosine kinases (RTKs), which has led to effective therapeutics targeting oncogenic signaling of RTK variants. Somatic hotspot mutations and structural amplifications and fusions affecting fibroblast growth factor receptor 2 (FGFR2) likewise occur in multiple tumor types including breast cancer. However, clinical responses to FGFR inhibitors have remained variable, emphasizing a need to better understand which FGFR2 alterations are oncogenic and therapeutically targetable. We applied transposon-based screening and tumor modelling in the mouse mammary gland to uncover truncation of the last exon (E18) of Fgfr2 as a potent driver mutation. Mouse and human FGFR2-E18 encodes the C-terminus of this RTK. Human oncogenomic datasets revealed a plethora of somatic FGFR2 alterations potentially causing transcription of E18-truncated FGFR2. These alterations were comprised of canonical in-frame fusions as well as diverse FGFR2 variants of unknown significance (VUS), which included non-canonical rearrangements, E1-E17 partial amplifications, and E18 nonsense and frameshift mutations. Functional in vitro and in vivo interrogation of a compendium of E18-truncated and full-length FGFR2 variants pinpointed FGFR2-E18 truncation as single-driver alteration in cancer. In contrast, the oncogenic competence of FGFR2 full-length amplifications depended on a distinct cooperating driver gene landscape. Notably, gradual truncation and site-directed mutagenesis of Fgfr2-E18 identified a novel 2-amino-acid motif within the C-terminus critical for kinase domain binding and suppression of oncogenic FGFR2 signaling. Aberration of this motif conspired with the loss of the receptor internalization motif to fully phenocopy oncogenicity of E18-truncated Fgfr2. These data suggest that genomic alterations that generate stable E18-truncated FGFR2 variants are actionable therapeutic targets, which we confirmed in preclinical mouse and human tumor models, and in a clinical trial. Thus, we uncovered a novel paradigm in oncogenic FGFR2 signaling and propose that breast and other cancers harboring any FGFR2 variant that truncates E18 should be considered for FGFR-targeted therapies.

Citation Format: Daniel Kaspar Zingg, Jinhyuk Bhin, Julia Yemelyanenko, Sjors M. Kas, Catrin Lutz, Chi-Chuan Lin, Sjoerd Klarenbeek, Jessica K. Lee, Ian M. Silverman, Stefano Annunziato, Marieke van de Ven, Siraj M. Ali, Timothy C. Burn, Shridar Ganesan, Lodewyk F. Wessels, Jos Jonkers. Truncated FGFR2 - a clinically actionable oncogene in multiple cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3488.

Biology and Targetability of the Extended Spectrum of PIK3CA Mutations Detected in Breast Carcinoma

PURPOSE

Alpelisib is a PI3K alpha (PI3Kα)-selective inhibitor approved for the treatment of hormone receptor-positive/HER2-negative (HR+/HER2-) PIK3CA-mutated advanced breast cancer (ABC) based on the SOLAR-1 trial, which defined 11 substitutions in exons 7, 9, and 20 in PIK3CA (SOLAR1m). We report alpelisib effectiveness for ABC harboring SOLAR1m, as well as other pathogenic PIK3CA mutations (OTHERm) using comprehensive genomic profiling (CGP).

EXPERIMENTAL DESIGN

A total of 33,977 tissue and 1,587 liquid biopsies were analyzed using hybrid capture-based CGP covering the entire coding sequence of PIK3CA. Clinical characteristics and treatment history were available for 10,750 patients with ABC in the deidentified Flatiron Health-Foundation Medicine clinico-genomic database (FH-FMI CGDB).

RESULTS

PIK3CAm were detected in 11,767/33,977 (35%) of tissue biopsies, including 2,300 (7%) samples with OTHERm and no SOLAR1m. Liquid biopsy had 77% sensitivity detecting PIK3CAm, increasing to 95% with circulating tumor DNA fraction ≥2%. In patients with HR+/HER2- ABC and PIK3CAm receiving alpelisib/fulvestrant (ALP+FUL; n = 182) or fulvestrant alone (FUL; n = 119), median real-world progression-free survival (rwPFS) was 5.9 months on ALP+FUL [95% confidence interval (CI): 5.1-7.4] versus 3.1 months on FUL (95% CI: 2.7-3.7; P < 0.0001). In patients with OTHERm, median rwPFS was 4.0 months on ALP+FUL (95% CI: 2.8-10.1) versus 2.5 months on FUL (95% CI: 2.2-3.7; P = 0.0054).

CONCLUSIONS

CGP detects diverse PIK3CAm in a greater number of patients with ABC than PCR hotspot testing; 20% of patients with PIK3CAm do not have SOLAR1m. These patients may derive benefit from alpelisib. See related commentary by Tau and Miller, p. 989.

Early circulating tumor DNA dynamics as a pan-tumor biomarker for long-term clinical outcome in patients treated with durvalumab and tremelimumab

There is an urgent need to identify biomarkers of early response that can accurately predict the benefit of immune checkpoint inhibitors (ICI). Patients receiving durvalumab/tremelimumab had tumor samples sequenced before treatment (baseline) to identify variants for the design of a personalized circulating tumor (ctDNA) assay. ctDNA was assessed at baseline and at 4 and/or 8 weeks into treatment. Correlations between ctDNA changes to radiographic response and overall survival (OS) were made to assess potential clinical benefit. 35/40 patients (87.5%) had personalized ctDNA assays designed, and 29/35 (82.9%) had plasma available for baseline analysis, representing 16 unique solid tumor histologies. As early as 4 weeks after treatment, decline in ctDNA from baseline predicted improved OS (P = 0.0144; HR = 9.98) and ctDNA changes on treatment-supported and refined radiographic response calls. ctDNA clearance at any time through week 8 identified complete responders by a median lead time of 11.5 months ahead of radiographic imaging. ctDNA response monitoring is emerging as a dynamic, personalized biomarker method that may predict survival outcomes in patients with diverse solid tumor histologies, complementing and sometimes preceding standard-of-care imaging assessments.

Comprehensive pan-cancer genomic landscape of KRAS altered cancers and real-world outcomes in solid tumors

Recent clinical development of KRAS inhibitors has heightened interest in the genomic landscape of KRAS-altered cancers. We performed a pan-cancer analysis of KRAS-altered samples from 426,706 adult patients with solid or hematologic malignancies using comprehensive genomic profiling; additional analyses included 62,369 liquid biopsy and 7241 pediatric samples. 23% of adult pan-cancer samples had KRAS alterations; 88% were mutations, most commonly G12D/G12V/G12C/G13D/G12R, and prevalence was similar in liquid biopsies. Co-alteration landscapes were largely similar across KRAS mutations but distinct from KRAS wild-type, though differences were observed in some tumor types for tumor mutational burden, PD-L1 expression, microsatellite instability, and other mutational signatures. Prognosis of KRAS-mutant versus other genomic cohorts of lung, pancreatic, and colorectal cancer were assessed using a real-world clinicogenomic database. As specific KRAS inhibitors and combination therapeutic strategies are being developed, genomic profiling to understand co-alterations and other biomarkers that may modulate response to targeted or immunotherapies will be imperative.

A High Percentage of NSCLC With Germline CHEK2 Mutation Harbors Actionable Driver Alterations: Survey of a Cancer Genomic Database and Review of Literature

Introduction

Germline CHEK2 mutations are rare and have not been associated with increased risk of NSCLC.

Methods

We identified two sequential primary NSCLCs harboring distinct actionable driver alterations (EGFR E746 _S752 delinsV and CD74-ROS1) in a patient with NSCLC with a novel germline CHEK2 mutation S5fs∗54 (c.14_20delCGGATGT). We queried a genomic database of NSCLC samples profiled by plasma next-generation sequencing (Foundation Medicine Inc.) and performed a literature search of germline CHEK2 mutations in NSCLC.

Results

Of 6101 patients with unique NSCLC profiled by plasma next-generation sequencing, 53 cases (0.87%) of germline CHEK2 mutation were identified (male-to-female ratio, 49%:51%; median age = 75 y). The median allele frequency of CHEK2 was 49% (interquartile range: 49%–51%). Ten unique CHEK2 germline mutations were identified. Literature review identified 15 additional cases of germline CHEK2 mutations in NSCLC. Overall, a total of 70 CHEK2 germline mutations (21 unique CHEK2 alterations) were identified. Among these 70 CHEK2 germline mutations, 54.3% were amino acid substitutions (point mutation), 40.0% were frameshift mutations, and 5.7% were splice site mutations. Of these 70 total cases assessed, 29 (41.4%) potentially actionable driver alterations were identified with KRAS G12C mutation (27.6%) being the most common and KRAS G12A/C/D/R/S/V mutations together constituting 51.7% of these driver mutations.

Conclusions

Germline CHEK2 mutations are rare in NSCLC. A large proportion of these cases harbor actionable driver alterations. The relationship between germline CHEK2 mutations and actionable driver alterations in NSCLC may be worth further investigation.

Truncated FGFR2 is a clinically actionable oncogene in multiple cancers

Somatic hotspot mutations and structural amplifications and fusions that affect fibroblast growth factor receptor 2 (encoded by FGFR2) occur in multiple types of cancer¹. However, clinical responses to FGFR inhibitors have remained variable^1–9, emphasizing the need to better understand which FGFR2 alterations are oncogenic and therapeutically targetable. Here we apply transposon-based screening^10,11 and tumour modelling in mice^12,13, and find that the truncation of exon 18 (E18) of Fgfr2 is a potent driver mutation. Human oncogenomic datasets revealed a diverse set of FGFR2 alterations, including rearrangements, E1–E17 partial amplifications, and E18 nonsense and frameshift mutations, each causing the transcription of E18-truncated FGFR2 (FGFR2^ΔE18). Functional in vitro and in vivo examination of a compendium of FGFR2^ΔE18 and full-length variants pinpointed FGFR2-E18 truncation as single-driver alteration in cancer. By contrast, the oncogenic competence of FGFR2 full-length amplifications depended on a distinct landscape of cooperating driver genes. This suggests that genomic alterations that generate stable FGFR2^ΔE18 variants are actionable therapeutic targets, which we confirmed in preclinical mouse and human tumour models, and in a clinical trial. We propose that cancers containing any FGFR2 variant with a truncated E18 should be considered for FGFR-targeted therapies.

Truncation of exon 18 of FGFR2 (FGFR2^ΔE18) is a potent driver mutation in mice and humans, and FGFR-targeted therapy should be considered for patients with cancer expressing stable FGFR2^ΔE18 variants.

Recovery from Cranial Nerve Symptoms after Flow Diversion without Coiling for Unruptured Very Large and Giant ICA Aneurysms

BACKGROUND AND PURPOSE

Cranial nerve symptoms, including visual impairment and ophthalmoplegia, are one of the most common presentations of very large and giant (≥15 mm) ICA aneurysms. In this study, we evaluated the treatment outcomes of flow diversion and conventional coiling in terms of recovery from cranial nerve symptoms and postoperative complications.

MATERIALS AND METHODS

Seventy-nine patients with unruptured ICA aneurysms of >15 mm who were treated with flow diversion or conventional coiling between December 2009 and December 2020 were retrospectively evaluated. We compared the radiologic and clinical outcomes, including recovery from cranial nerve symptoms, between the 2 groups.

RESULTS

Twenty-eight of 49 patients (57.1%) treated with flow diversion and 10 of 30 patients (33.3%) treated with conventional coiling initially presented with cranial nerve symptoms (P = .068). In the clinical follow-up, the symptom recovery rate was significantly higher in those treated with flow diversion (15 [50%] versus 3 [25%] with conventional coiling, P = .046). Multivariate logistic regression analysis demonstrated that flow diversion was significantly associated with symptom recovery (OR, 7.425; 95% CI, 1.091-50.546; P = .040). The overall postoperative complication rate was similar (flow diversion, 10 [20.4%]; conventional coiling, 6 [20.0%], P = .965), though fatal hemorrhagic complications occurred only in patients with intradurally located aneurysms treated with flow diversion (4 [8.2%] versus 0 [0.0%] with coiling, P = .108).

CONCLUSIONS

Flow diversion without coiling for very large and giant ICA aneurysms yielded a higher rate of recovery from cranial nerve symptoms, but it may be related to an increased hemorrhagic complication rate, especially for intradurally located aneurysms.

The Effects of 30 Minutes of Artificial Gravity on Cognitive and Sensorimotor Performance in a Spaceflight Analog Environment

The altered vestibular signaling and somatosensory unloading of microgravity result in sensory reweighting and adaptation to conflicting sensory inputs. Aftereffects of these adaptive changes are evident postflight as impairments in behaviors such as balance and gait. Microgravity also induces fluid shifts toward the head and an upward shift of the brain within the skull; these changes are well-replicated in strict head-down tilt bed rest (HDBR), a spaceflight analog environment. Artificial gravity (AG) is a potential countermeasure to mitigate these effects of microgravity. A previous study demonstrated that intermittent (six, 5-mins bouts per day) daily AG sessions were more efficacious at counteracting orthostatic intolerance in a 5 day HDBR study than continuous daily AG. Here we examined whether intermittent daily AG was also more effective than continuous dosing for mitigating brain and behavioral changes in response to 60 days of HDBR. Participants (n = 24) were split evenly between three groups. The first received 30 mins of continuous AG daily (cAG). The second received 30 mins of intermittent AG daily (6 bouts of 5 mins; iAG). The third received no AG (Ctrl). We collected a broad range of sensorimotor, cognitive, and brain structural and functional assessments before, during, and after the 60 days of HDBR. We observed no significant differences between the three groups in terms of HDBR-associated changes in cognition, balance, and functional mobility. Interestingly, the intermittent AG group reported less severe motion sickness symptoms than the continuous group during centrifugation; iAG motion sickness levels were not elevated above those of controls who did not undergo AG. They also had a shorter duration of post-AG illusory motion than cAG. Moreover, the two AG groups performed the paced auditory serial addition test weekly while undergoing AG; their performance was more accurate than that of controls, who performed the test while in HDBR. Although AG did not counteract HDBR-induced gait and balance declines, iAG did not cause motion sickness and was associated with better self-motion perception during AG ramp-down. Additionally, both AG groups had superior cognitive performance while undergoing AG relative to controls; this may reflect attention or motivation differences between the groups.

The Genomics of Colorectal Cancer in Populations with African and European Ancestry

Blacks have a higher incidence of colorectal cancer (CRC) and worse survival rates when compared to Whites. Comprehensive genomic profiling was performed in 46,140 colorectal adenocarcinoma cases. Ancestry-informative markers identified 5,301 patients of African descent (AFR) and 33,770 patients of European descent (EUR). AFR were younger, had fewer MSI-H tumors, and had significantly more frequent alterations in KRAS, APC, and PIK3CA. AFR had increased frequency of KRAS mutations specifically KRAS G12D and KRAS G13. There were no differences in rates of actionable kinase driver alterations (HER2, MET, NTRK, ALK, ROS1, RET). In patients with young onset CRC (&lt;50 years), AFR and EUR had similar frequency of MSI-H and TMB-H tumors, and strikingly different trends in APC mutations by age, as well as differences in MAPK pathway alterations. These findings inform treatment decisions, impact prognosis, and underscore the need for model systems representative of our diverse US population.

The Pan-Tumor Landscape of Targetable Kinase Fusions in Circulating Tumor DNA

PURPOSE

Oncogenic kinase fusions are targetable with approved and investigational therapies and can also mediate acquired resistance (AR) to targeted therapy. We aimed to understand the clinical validity of liquid biopsy comprehensive genomic profiling (CGP) to detect kinase fusions pan tumor.

EXPERIMENTAL DESIGN

CGP was performed on plasma and tissue samples during clinical care. All exons plus selected introns of 16 kinases involved in oncogenic fusions (ALK, BRAF, EGFR, ERBB2, FGFR1/2/3, MET, NTRK1/2/3, PDGFRA/B, RAF1, RET, and ROS1) were sequenced to capture fusions, including well-characterized and novel breakpoints. Plasma circulating tumor DNA (ctDNA) fraction was estimated to inform sensitivity.

RESULTS

Of 36,916 plasma cases, 32,492 (88%) had detectable ctDNA. Kinase fusions were detected in 1.8% of ctDNA-positive cases (571/32,492) and were most prevalent in patients with cholangiocarcinoma (4.2%), bladder cancer (3.6%), and non-small cell lung cancer (NSCLC; 3.1%). Of the 63 paired patient samples that had tissue and ctDNA specimens collected within 1 year and with estimated plasma ctDNA fraction >1%, fusions were detected in 47 of 51 (92%) liquid specimens with a fusion in the tissue sample. In 32 patients with fusions detected in liquid but not in tissue, 21 (66%) had evidence of putative acquired resistance.

CONCLUSIONS

Targetable kinase fusions are identified in ctDNA across cancer types. In pairs with tissue-identified fusions, fusion detection in ctDNA is reliable with elevated ctDNA fraction. These data support the validity of CGP to enable ctDNA-based fusion detection for informing clinical care in patients with advanced cancer.

Immunoglobulin D Multiple Myeloma with a “Hidden” Lambda Light Chain

Introduction/Objective

In rare cases, the conventional immunofixation gel electrophoresis technique fails to detect the light chain of an M-protein. We report a case of immunoglobulin (Ig) D multiple myeloma with a hidden lambda (λ) light chain.

Methods/Case Report

Capillary electrophoresis (CE) (Sebia CAPILLARYS 2) was used to detect and quantify M- proteins in serum specimens. Immunosubtraction (IS) on the CAPILLARYS 2 systems was used to identify the classes of M-proteins. Conventional gel immunofixation electrophoresis (IFE) was performed, using monospecific antisera for IgD, IgE, kappa (κ) or λ in the Sebia HYDRASYS system, and IgG, IgA, IgM, κ or λ in the Helena SPIFE3000 system. Beta-mercaptoethanol (BME) with Fluidil were used as reduction agents.

Results (if a Case Study enter NA)

Results of serum CE showed two abnormal peaks in beta 2 and gamma regions, suspected to be positive for M-proteins. IS results showed subtraction for λ light chain only in both peaks, suggesting two monoclonal λ light chains. In contrary, no monoclonal λ light chain was detected in gamma region by IFE (Sebia). Epitope masking in the folded monoclonal protein was suspected to cause the “hidden λ light chain” and was further investigated by two laboratory approaches. IFE performed on the Helena SPIFE3000 system found two λ bands in beta 2 and gamma regions, which was consistent with the results from IS. The treatment of BME with Fluidil helped unmasking the hidden epitope and revealed the λ band in gamma region on IFE (Sebia).

Conclusion

The medical laboratories should be aware of the described scenario. The failure to detect light chains of certain intact M-proteins is most likely due to the structurally inaccessibility of light chains. It is recommended that treatment with reduction agents or use of an alternative methodology or IS might be helpful for investigating suspected heavy chain only cases, due to the limitation of conventional methodology.

The Variations of Insulin-like Growth Factor 1 Measured between Siemens Immulite, DiaSorin Liaison and IDS iSYS

Introduction/Objective

Insulin-like Growth Factor 1 (IGF-1) is a biomarker for the evaluation of growth hormone activity in the hypothalamic-pituitary axis. The current most common methodology for IGF-1 measurement is automated immunometric assays. In this study, we compared the IGF-1 on Siemens Immulite 2000, DiaSorin Liaison XL and IDS iSYS.

Methods/Case Report

Residual 30-110 serum specimens were randomly selected from routine hospital orders. IGF- 1 was measured on these three platforms and compared with Passing-Bablok regression. Bias was evaluated using the Bland-Altman method.

Results (if a Case Study enter NA)

Weighted Deming regression analysis showed approximately 80% and 56% positive bias on IDS iSYS and DiaSorin Liaison, compared with Siemens Immulite (iSYS=1.81*Immulite-117.65, r=0.91; Liaison=1.56*Immulite-4.58, r=0.98). There was approximately 8% positive bias on Liaison, compared with iSYS (Liaison=1.08*iSYS+0.56, r=0.99). The Passing-Bablok regression analysis revealed approximately 67% and 54% positive bias (iSYS=1.67*Immulite-75, r=0.91; Liaison=1.54*Immulite-3.44, r=0.91). Approximately 8% positive bias on Liaison was observed, compared with iSYS (Liaison=1.08*iSYS+5.65, r=0.99). The Bland-Altman plot showed the agreement between iSYS and Immulite IGF-1 was on average 129.6±123.3 ng/mL, 98.6±148.8 ng/mL between Liaison and Immulite and 37.0±46.5 ng/mL between Liaison and iSYS.

Conclusion

Immunoassays rely on the specificity of antibodies. There are wide variations between different immunoassay platforms for IGF-1 measurement. The standardization of IGF-1 assay is lack. It would be a challenge for clinicians to monitor IGF-1 or treat the patients with pituitary disorders, when switching to another platform. The potential impact of the variations in IGF-1 measurement between different immunoassay platforms should be aware.

Characterization of Non-Small-Cell Lung Cancers With MET Exon 14 Skipping Alterations Detected in Tissue or Liquid: Clinicogenomics and Real-World Treatment Patterns

PURPOSE

MET exon 14 (METex14) skipping alterations are oncogenic drivers in non–small-cell lung cancer (NSCLC). We present a comprehensive overview of METex14 samples from 1,592 patients with NSCLC, associated clinicogenomic characteristics, potential mechanisms of acquired resistance, treatment patterns, and outcomes to MET inhibitors.

METHODS

Hybrid capture–based comprehensive genomic profiling (CGP) was performed on samples from 69,219 patients with NSCLC. For treatment patterns and outcomes analysis, patients with advanced METex14-altered NSCLC were selected from the Flatiron Health-Foundation Medicine clinicogenomic database, a nationwide deidentified electronic health record–derived database linked to Foundation Medicine CGP for patients treated between January 2011 and March 2020.

RESULTS

A total of 1,592 patients with NSCLC (2.3%) were identified with 1,599 METex14 alterations spanning multiple functional sites (1,458 of 60,244 tissue samples and 134 of 8,975 liquid samples). Low tumor mutational burden and high programmed death ligand 1 expression were enriched in METex14-altered samples. MDM2, CDK4, and MET coamplifications and TP53 mutations were present in 34%, 19%, 11%, and 42% of tissue samples, respectively. Comparing tissue and liquid cohorts, coalteration frequency and acquired resistance mechanisms, including multiple MET mutations, EGFR, ERBB2, KRAS, and PI3K pathway alterations, were generally similar. Positive percent agreement with the tissue was 100% for METex14 pairs collected within 1 year (n = 7). Treatment patterns showed increasing adoption of MET inhibitors in METex14-altered NSCLC after receipt of CGP results; the real-world response rate to MET inhibitors was 45%, and time to treatment discontinuation was 4.4 months.

CONCLUSION

Diverse METex14 alterations were present in 2%-3% of NSCLC cases. Tissue and liquid comparisons showed high concordance and similar coalteration profiles. Characterizing common co-occurring alterations and immunotherapy biomarkers, including those present before or acquired after treatment, may be critical for predicting responses to MET inhibitors and informing rational combination strategies.

Ophthalmic changes in a spaceflight analog are associated with brain functional reorganization

Following long-duration spaceflight, some astronauts exhibit ophthalmic structural changes referred to as Spaceflight Associated Neuro-ocular Syndrome (SANS). Optic disc edema is a common sign of SANS. The origin and effects of SANS are not understood as signs of SANS have not manifested in previous spaceflight analog studies. In the current spaceflight analog study, 11 subjects underwent 30 days of strict head down-tilt bed rest in elevated ambient carbon dioxide (HDBR+CO2 ). Using functional magnetic resonance imaging (fMRI), we acquired resting-state fMRI data at 6 time points: before (2), during (2), and after (2) the HDBR+CO2 intervention. Five participants developed optic disc edema during the intervention (SANS subgroup) and 6 did not (NoSANS group). This occurrence allowed us to explore whether development of signs of SANS during the spaceflight analog impacted resting-state functional connectivity during HDBR+CO2 . In light of previous work identifying genetic and biochemical predictors of SANS, we further assessed whether the SANS and NoSANS subgroups exhibited differential patterns of resting-state functional connectivity prior to the HDBR+CO2 intervention. We found that the SANS and NoSANS subgroups exhibited distinct patterns of resting-state functional connectivity changes during HDBR+CO2 within visual and vestibular-related brain networks. The SANS and NoSANS subgroups also exhibited different resting-state functional connectivity prior to HDBR+CO2 within a visual cortical network and within a large-scale network of brain areas involved in multisensory integration. We further present associations between functional connectivity within the identified networks and previously identified genetic and biochemical predictors of SANS. Subgroup differences in resting-state functional connectivity changes may reflect differential patterns of visual and vestibular reweighting as optic disc edema develops during the spaceflight analog. This finding suggests that SANS impacts not only neuro-ocular structures, but also functional brain organization. Future prospective investigations incorporating sensory assessments are required to determine the functional significance of the observed connectivity differences.

Head-Down-Tilt Bed Rest With Elevated CO2: Effects of a Pilot Spaceflight Analog on Neural Function and Performance During a Cognitive-Motor Dual Task

Spaceflight has widespread effects on human performance, including on the ability to dual task. Here, we examine how a spaceflight analog comprising 30 days of head-down-tilt bed rest (HDBR) combined with 0.5% ambient CO2 (HDBR + CO2) influences performance and functional activity of the brain during single and dual tasking of a cognitive and a motor task. The addition of CO2 to HDBR is thought to better mimic the conditions aboard the International Space Station. Participants completed three tasks: (1) COUNT: counting the number of times an oddball stimulus was presented among distractors; (2) TAP: tapping one of two buttons in response to a visual cue; and (3) DUAL: performing both tasks concurrently. Eleven participants (six males) underwent functional MRI (fMRI) while performing these tasks at six time points: twice before HDBR + CO2, twice during HDBR + CO2, and twice after HDBR + CO2. Behavioral measures included reaction time, standard error of reaction time, and tapping accuracy during the TAP and DUAL tasks, and the dual task cost (DTCost) of each of these measures. We also quantified DTCost of fMRI brain activation. In our previous HDBR study of 13 participants (with atmospheric CO2), subjects experienced TAP accuracy improvements during bed rest, whereas TAP accuracy declined while in the current study of HDBR + CO2. In the HDBR + CO2 subjects, we identified a region in the superior frontal gyrus that showed decreased DTCost of brain activation while in HDBR + CO2, and recovered back to baseline levels before the completion of bed rest. Compared to HDBR alone, we found different patterns of brain activation change with HDBR + CO2. HDBR + CO2 subjects had increased DTCost in the middle temporal gyrus whereas HDBR subjects had decreased DTCost in the same area. Five of the HDBR + CO2 subjects developed signs of spaceflight-associated neuro-ocular syndrome (SANS). These subjects exhibited lower baseline dual task activation and higher slopes of change during HDBR + CO2 than subjects with no signs of SANS. Collectively, this pilot study provides insight into the additional and/or interactive effects of CO2 levels during HDBR, and information regarding the impacts of this spaceflight analog environment on the neural correlates of dual tasking.

Effects of long-term immobilisation on endomysium of the soleus muscle in humans

NEW FINDINGS

What is the central question of this study? While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest? What is the main finding and its importance? Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness.

ABSTRACT

Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-to-fibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness.

Development of the Asia Pacific Consortium on Osteoporosis (APCO) Framework: clinical standards of care for the screening, diagnosis, and management of osteoporosis in the Asia-Pacific region

Guidelines for doctors managing osteoporosis in the Asia-Pacific region vary widely. We compared 18 guidelines for similarities and differences in five key areas. We then used a structured consensus process to develop clinical standards of care for the diagnosis and management of osteoporosis and for improving the quality of care.

PURPOSE

Minimum clinical standards for assessment and management of osteoporosis are needed in the Asia-Pacific (AP) region to inform clinical practice guidelines (CPGs) and to improve osteoporosis care. We present the framework of these clinical standards and describe its development.

METHODS

We conducted a structured comparative analysis of existing CPGs in the AP region using a "5IQ" model (identification, investigation, information, intervention, integration, and quality). One-hundred data elements were extracted from each guideline. We then employed a four-round Delphi consensus process to structure the framework, identify key components of guidance, and develop clinical care standards.

RESULTS

Eighteen guidelines were included. The 5IQ analysis demonstrated marked heterogeneity, notably in guidance on risk factors, the use of biochemical markers, self-care information for patients, indications for osteoporosis treatment, use of fracture risk assessment tools, and protocols for monitoring treatment. There was minimal guidance on long-term management plans or on strategies and systems for clinical quality improvement. Twenty-nine APCO members participated in the Delphi process, resulting in consensus on 16 clinical standards, with levels of attainment defined for those on identification and investigation of fragility fractures, vertebral fracture assessment, and inclusion of quality metrics in guidelines.

CONCLUSION

The 5IQ analysis confirmed previous anecdotal observations of marked heterogeneity of osteoporosis clinical guidelines in the AP region. The Framework provides practical, clear, and feasible recommendations for osteoporosis care and can be adapted for use in other such vastly diverse regions. Implementation of the standards is expected to significantly lessen the global burden of osteoporosis.

Visuomotor Adaptation Brain Changes During a Spaceflight Analog With Elevated Carbon Dioxide (CO2): A Pilot Study

Astronauts on board the International Space Station (ISS) must adapt to several environmental challenges including microgravity, elevated carbon dioxide (CO₂), and isolation while performing highly controlled movements with complex equipment. Head down tilt bed rest (HDBR) is an analog used to study spaceflight factors including body unloading and headward fluid shifts. We recently reported how HDBR with elevated CO₂ (HDBR+CO₂) affects visuomotor adaptation. Here we expand upon this work and examine the effects of HDBR+CO₂ on brain activity during visuomotor adaptation. Eleven participants (34 ± 8 years) completed six functional MRI (fMRI) sessions pre-, during, and post-HDBR+CO₂. During fMRI, participants completed a visuomotor adaptation task, divided into baseline, early, late and de-adaptation. Additionally, we compare brain activity between this NASA campaign (30-day HDBR+CO₂) and a different campaign with a separate set of participants (60-day HDBR with normal atmospheric CO₂ levels, n = 8; 34.25 ± 7.9 years) to characterize the specific effects of CO₂. Participants were included by convenience. During early adaptation across the HDBR+CO₂ intervention, participants showed decreasing activation in temporal and subcortical brain regions, followed by post- HDBR+CO₂ recovery. During late adaptation, participants showed increasing activation in the right fusiform gyrus and right caudate nucleus during HDBR+CO₂; this activation normalized to baseline levels after bed rest. There were no correlations between brain changes and adaptation performance changes from pre- to post HDBR+CO₂. Also, there were no statistically significant differences between the HDBR+CO₂ group and the HDBR controls, suggesting that changes in brain activity were due primarily to bed rest rather than elevated CO₂. Five HDBR+CO₂ participants presented with optic disc edema, a sign of Spaceflight Associated Neuro-ocular Syndrome (SANS). An exploratory analysis of HDBR+CO₂ participants with and without signs of SANS revealed no group differences in brain activity during any phase of the adaptation task. Overall, these findings have implications for spaceflight missions and training, as ISS missions require individuals to adapt to altered sensory inputs over long periods in space. Further, this is the first study to verify the HDBR and elevated CO₂ effects on the neural correlates of visuomotor adaptation.

Effects of Spaceflight Stressors on Brain Volume, Microstructure, and Intracranial Fluid Distribution

Astronauts are exposed to elevated CO₂ levels onboard the International Space Station. Here, we investigated structural brain changes in 11 participants following 30-days of head-down tilt bed rest (HDBR) combined with 0.5% ambient CO₂ (HDBR + CO₂) as a spaceflight analog. We contrasted brain changes observed in the HDBR + CO₂ group with those of a previous HDBR sample not exposed to elevated CO₂. Both groups exhibited a global upward shift of the brain and concomitant intracranial free water (FW) redistribution. Greater gray matter changes were seen in the HDBR + CO₂ group in some regions. The HDBR + CO₂ group showed significantly greater FW decrements in the posterior cerebellum and the cerebrum than the HDBR group. In comparison to the HDBR group, the HDBR + CO₂ group exhibited greater diffusivity increases. In half of the participants, the HDBR + CO₂ intervention resulted in signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), a constellation of ocular structural and functional changes seen in astronauts. We therefore conducted an exploratory comparison compared between subjects that did and did not develop SANS and found asymmetric lateral ventricle enlargement in the SANS group. These results enhance our understanding of the underlying mechanisms of spaceflight-induced brain changes, which is critical for promoting astronaut health and performance.

Society of Family Planning clinical recommendations: Management of individuals with bleeding or thrombotic disorders undergoing abortion

Individuals who have bleeding disorders, thrombophilias, a history of venous thromboembolism (VTE), or who are taking anticoagulation medication for other reasons may present for abortion. Clinicians should be aware of risk factors and histories concerning for excessive bleeding and thrombotic disorders around the time of abortion. This document will focus on how to approach abortion planning in these individuals. For first-trimester abortion, procedural abortion (sometimes called surgical abortion) is generally preferred over medical management for individuals with bleeding disorders or who are on anticoagulation. First-trimester procedural abortion in an individual on anticoagulation can generally be done without interruption of anticoagulation. The decision to interrupt anticoagulation for a second-trimester procedure should be individualized. Individuals at high risk for VTE can be offered anticoagulation post-procedure. Individuals with bleeding disorders or who are anticoagulated can safely be offered progestin intrauterine devices. Future research is needed to better assess quantitative blood loss and complications rates with abortion in these populations.

Altered cerebral perfusion in response to chronic mild hypercapnia and head-down tilt Bed rest as an analog for Spaceflight

PURPOSE

Following prolonged stays on the International Space Station (ISS), some astronauts exhibit visual acuity changes, ophthalmological findings, and mildly elevated intracranial pressures as part of a novel process called spaceflight-associated neuro-ocular syndrome (SANS). To determine the pathophysiology of SANS, NASA conducted a multi-investigator study in which 11 healthy participants underwent head-down tilt bed rest, mimicking microgravity-induced cephalad fluid shifts, combined with elevated ambient CO₂ levels similar to those on the ISS (HDT+CO₂). As part of that study, we examined the effects of HDT+CO₂ on cerebral perfusion.

METHODS

Using arterial spin labeling, we compared cerebral perfusion before, during, and after HDT+CO₂ in participants who developed SANS (n = 5) with those who did not (n = 6).

RESULTS

All participants demonstrated a decrease in perfusion during HDT+CO2 (mean decrease of 25.1% at HDT7 and 16.2% at HDT29); however, the timing and degree of change varied between the groups. At day 7 of HDT+CO₂, the SANS group experienced a greater reduction in perfusion than the non-SANS group (p =.05, 95% CI:-0.19 to 16.11, d=.94, large effect). Conversely, by day 29 of HDT+CO₂, the SANS group had significantly higher perfusion (approaching their baseline) than the non-SANS group (p = .04, 95% CI:0.33 to 13.07, d=1.01, large effect).

CONCLUSION

Compared with baseline and recovery, HDT+CO₂ resulted in reduced cerebral perfusion which varied based on SANS status. Further studies are needed to unravel the relative role of HDT vs hypercapnia, to determine if these perfusion changes are clinically relevant, and whether perfusion changes contribute to the development of SANS during spaceflight.

RAS Amplification as a Negative Predictor of Benefit from Anti-EGFR-Containing Therapy Regimens in Metastatic Colorectal Cancer

BACKGROUND

RAS short variant (SV) mutations in colorectal cancer (CRC) are associated with lack of benefit from epidermal growth factor receptor (EGFR) monoclonal antibody (EGFRmAb). However, the clinical implications for RAS amplification (RASa) as a biomarker for anti-EGFR therapy in CRC remain ill defined.

METHODS

Genomic analysis was performed using the Foundation Medicine (FM) comprehensive genomic profiling database of 37,233 CRC cases. Clinical outcomes were assessed using two independent cohorts: the City of Hope (COH) cohort of 338 patients with metastatic CRC (mCRC) and the Flatiron Health-FM real-world clinicogenomic database (CGDB) of 3,904 patients with mCRC.

RESULTS

RASa was detected in 1.6% (614/37,233) of primarily mCRC. RASa 6-9 (n = 241, 39%), 10-19 (n = 165, 27%), and ≥ 20 (n = 209, 34%) copy number subsets had co-RAS SV/BRAF V600E in 63%/3%, 31%/0.6%, and 4.8%/0% of cases, respectively. In the COH cohort, six patients with RASa (13-54 copies) received EGFRmAb, four of six had progressive disease, two had stable disease, and median time to treatment discontinuation (TTD) was 2.5 months. Of the CGDB EGFRmAb-treated patients, those with RASa (n = 9) had median TTD of 4.7 months and overall survival (OS) of 11.4 months, those with RAS SV (n = 101) had median TTD and OS of 5.3 and 9.4 months, and those with RAS/BRAF wild-type (n = 608) had median TTD and OS of 7.6 and 13.7 months.

CONCLUSION

Patients with RASa without RAS mutations (1.1% of mCRC) may have poor outcomes on EGFRmAb, although numbers herein were small, and interpretation is confounded by combination chemotherapy. Larger independent studies are warranted to determine if RASa, including degree of amplification, may act similarly to RAS mutation as a resistance mechanism to EGFRmAb therapies.

IMPLICATIONS FOR PRACTICE

Genomic data suggest that RAS amplification occurs as the sole RAS/RAF alteration in >1% of colorectal cancer cases and that degree of amplification inversely correlates with co-occurring MAPK pathway alterations. Preliminary clinical evidence suggests that RAS amplification may function similarly to RAS mutation as a negative predictor of benefit from anti-epidermal growth factor receptor therapies in colorectal cancer. More clinical data are needed, and comprehensive genomic profiling, including detection of RAS amplification, should be used in trial design to inform therapy selection.

The effects of a spaceflight analog with elevated CO2 on sensorimotor adaptation

Aboard the International Space Station (ISS), astronauts must adapt to altered vestibular and somatosensory inputs due to microgravity. Sensorimotor adaptation on Earth is often studied with a task that introduces visuomotor conflict. Retention of the adaptation process, known as savings, can be measured when subjects are exposed to the same adaptive task multiple times. It is unclear how adaptation demands found on the ISS might interfere with the ability to adapt to other sensory conflict at the same time. In the present study, we investigated the impact of 30 days' head-down tilt bed rest combined with elevated carbon dioxide (HDBR + CO₂) as a spaceflight analog on sensorimotor adaptation. Eleven subjects used a joystick to move a cursor to targets presented on a computer screen under veridical cursor feedback and 45° rotated feedback. During this NASA campaign, five individuals presented with optic disk edema, a sign of spaceflight-associated neuro-ocular syndrome (SANS). Thus, we also performed post hoc exploratory analyses between subgroups who did and did not show signs of SANS. HDBR + CO₂ had some impact on sensorimotor adaptation, with a lack of savings across the whole group. SANS individuals showed larger, more persistent after-effects, suggesting a shift from relying on cognitive to more implicit processing of adaptive behaviors. Overall, these findings suggest that HDBR + CO₂ alters the way in which individuals engage in sensorimotor processing. These findings have important implications for missions and mission training, which require individuals to adapt to altered sensory inputs over long periods in space.NEW & NOTEWORTHY This is the first bed rest campaign examining sensorimotor adaptation and savings in response to the combined effect of HDBR + CO2 and to observe signs of spaceflight-associated neuro-ocular syndrome (SANS) in HDBR participants. Our findings suggest that HDBR + CO2 alters the way that individuals engage in sensorimotor processing. Individuals who developed signs of SANS seem to rely more on implicit rather than cognitive processing of adaptive behaviors than subjects who did not present signs of SANS.

Blindness increases the risk for hip fracture and vertebral fracture but not the risk for distal radius fracture: a longitudinal follow-up study using a national sample cohort

The risks for hip fracture and vertebral fracture, but not the risk for distal radius fracture, were significantly higher in the blindness group than in the control group with a maximum 12-year follow-up.

PURPOSE

To evaluate the influence of visual impairment on the risk for osteoporotic fractures at common sites: hip, thoracic/lumbar vertebra, and distal radius.

METHODS

This longitudinal follow-up study used a database of a national sample cohort from 2002 to 2013 provided by the Korean National Health Insurance Service. Of a total of 1,125,691 subjects, 3918 patients with visual impairment and age ≥ 50 years were enrolled in a 1:4 ratio; 15,672 control participants were matched for age, sex, income, and region of residence. Stratified Cox proportional-hazards models were used to evaluate the crude and adjusted (for steroid medication, rheumatoid arthritis, depression, osteoporosis, diabetes mellitus, and stroke history) hazard ratios (HRs) for each fracture site. Fracture diagnoses were based on the ICD-10 codes: hip fracture (S720, S721, S722), vertebral fracture (S220, S320), and distal radius fracture (S525).

RESULTS

The HRs for hip and vertebral fracture were significantly higher in the blindness group (adjusted HR = 2.46, p < 0.001 for hip fracture; adjusted HR = 1.42, p = 0.020 for thoracic/lumbar vertebral fracture) than in the matched control group. However, the HR for distal radius fracture was not higher in the blindness group. The HRs for all three fracture sites were not significantly higher in the non-blindness visual impairment group after adjustment.

CONCLUSION

The risks for hip fracture and vertebral fracture were significantly higher in the blindness group. However, the risk for distal radius fracture was not related to visual impairment including blindness.

The Current and Future Challenges of Hip Fracture Management in Malaysia

By 2050, it is predicted that six million hip fractures will occur each year of which the majority will happen in Asia. Malaysia is not spared from this predicted rise and its rate of increase will be one of the highest in this region. Much of this is driven by our unprecedented growth in the number of older people. Characteristics of individuals with hip fractures in Malaysia mirror what has been reported in other countries. They will be older multimorbid people who were already at risk of falls and fractures. Outcomes were poor with at least a quarter do not survive beyond 12 months and in those that do survive have limitation in their mobility and activities of daily living. Reviewing how these fractures are managed and incorporating new models of care, such as orthogeriatric care, could address these poor outcomes. Experts have warned of the devastating impact of hip fracture in Malaysia and that prompt action is urgently required. Despite that, there remains no national agenda to highlight the need to improve musculoskeletal health in the country.

Brain connectivity and behavioral changes in a spaceflight analog environment with elevated CO2

Astronauts are exposed to microgravity and elevated CO₂ levels onboard the International Space Station. Little is known about how microgravity and elevated CO₂ combine to affect the brain and sensorimotor performance during and after spaceflight. Here we examined changes in resting-state functional connectivity (FC) and sensorimotor behavior associated with a spaceflight analog environment. Participants underwent 30 days of strict 6^o head-down tilt bed rest with elevated ambient CO₂ (HDBR+CO₂). Resting-state functional magnetic resonance imaging and sensorimotor assessments were collected 13 and 7 days prior to bed rest, on days 7 and 29 of bed rest, and 0, 5, 12, and 13 days following bed rest. We assessed the time course of FC changes from before, during, to after HDBR+CO₂. We then compared the observed connectivity changes with those of a HDBR control group that underwent HDBR in standard ambient air. Moreover, we assessed associations between post-HDBR+CO₂ FC changes and alterations in sensorimotor performance. HDBR+CO₂ was associated with significant changes in functional connectivity between vestibular, visual, somatosensory and motor brain areas. Several of these sensory and motor regions showed post-HDBR+CO₂ FC changes that were significantly associated with alterations in sensorimotor performance. We propose that these FC changes reflect multisensory reweighting associated with adaptation to the HDBR+CO₂ microgravity analog environment. This knowledge will further improve HDBR as a model of microgravity exposure and contribute to our knowledge of brain and performance changes during and after spaceflight.

Cardiorespiratory and Neuromuscular Demand of Daily Centrifugation: Results From the 60-Day AGBRESA Bed Rest Study

Purpose

Long stays in space require countermeasures for the degrading effects of weightlessness on the human body, and artificial gravity (AG) has been proposed as an integrated countermeasure. The aim of this study was to assess the cardiorespiratory and neuromuscular demand of AG elicited via daily centrifugation during 60 days of bed rest.

Methods

Twenty four participants (33 ± 9 y, 175 ± 9 cm, 74 ± 10 kg, 8 female) were subjected to 60 days of strict six-degree head-down tilt (HDT) bed rest and were randomly allocated to one of three experimental groups: 30 min of daily centrifugation with an acceleration of 1 g at the center of mass and 2 g at the feet applied continuously (cAG) or intermittently in 6 epochs of 5 min each, separated by 3 min breaks (iAG), or non-centrifuged control (CTRL). Cardiorespiratory demand during centrifugation was assessed at the beginning (HDT3) and end (HDT60) of the bed rest phase via spirometry and heart rate monitoring, leg muscle activation was monitored via electromyography.

Results

On average, analyses of variance revealed that heart rate during centrifugation increased by 40% (iAG) and 60% (cAG) compared to resting values (p < 0.001), while oxygen uptake did not change significantly (p = 0.96). There was a preference for calf over knee extensor muscle activation (active time soleus 57 ± 27%, gastrocnemius medialis 45 ± 27% and vastus lateralis 27 ± 27%, p < 0.001), with large inter-individual differences in leg muscle active time. AG could not prevent the increase in resting heart rate after bed rest. For most of the recorded parameters, there were little differences between cAG and iAG, with the increase in heart rate during centrifugation being a notable exception (greater increase for cAG, p = 0.01).

Conclusion

Daily 30 min bouts of artificial gravity elicited by centrifugation put a substantial demand on the heart as a pump without increasing oxygen consumption. If centrifugation is to be used as a countermeasure for the deteriorating effects of microgravity on physical performance, we recommend combining it with strenuous exercise.

Neural Working Memory Changes During a Spaceflight Analog With Elevated Carbon Dioxide: A Pilot Study

Spaceflight missions to the International Space Station (ISS) expose astronauts to microgravity, radiation, isolation, and elevated carbon dioxide (CO₂), among other factors. Head down tilt bed rest (HDBR) is an Earth-based analog for spaceflight used to study body unloading, fluid shifts, and other factors unrelated to gravitational changes. While in space, astronauts need to use mental rotation strategies to facilitate their adaptation to the ISS environment. Therefore, spatial working memory is essential for crewmember performance. Although the effects of HDBR on spatial working memory have recently been studied, the results are still inconclusive. Here, we expand upon past work and examine the effects of HDBR with elevated CO₂ (HDBR + CO₂) on brain activation patterns during spatial working memory performance. In addition, we compare brain activation between 30 days of HDBR + CO₂ and 70 days of HDBR to test the isolated effect of CO₂. Eleven subjects (6 males, 5 females; mean age = 34 ± 8 years) underwent six functional magnetic resonance imaging (fMRI) sessions pre-, during, and post-HDBR + CO₂. During the HDBR + CO₂ intervention, we observed decreasing activation in the right middle frontal gyrus and left regions of the cerebellum, followed by post-intervention recovery. We detected several correlations between brain and behavioral slopes of change with the HDBR + CO₂ intervention. For example, greater increases in activation in frontal, temporal and parietal regions were associated with larger spatial working memory improvements. Comparing the HDBR + CO₂ group to data from our previous 70-day HDBR study, we found greater decreases in activation in the right hippocampus and left inferior temporal gyrus for the HDBR + CO₂ group over the course of the intervention. Together, these findings increase our understanding of the neural mechanisms of HDBR, elevated levels of CO₂ and spaceflight-related changes in spatial working memory performance.

The Impact of 6 and 12 Months in Space on Human Brain Structure and Intracranial Fluid Shifts

As plans develop for Mars missions, it is important to understand how long-duration spaceflight impacts brain health. Here we report how 12-month (n = 2 astronauts) versus 6-month (n = 10 astronauts) missions impact brain structure and fluid shifts. We collected MRI scans once before flight and four times after flight. Astronauts served as their own controls; we evaluated pre- to postflight changes and return toward preflight levels across the 4 postflight points. We also provide data to illustrate typical brain changes over 7 years in a reference dataset. Twelve months in space generally resulted in larger changes across multiple brain areas compared with 6-month missions and aging, particularly for fluid shifts. The majority of changes returned to preflight levels by 6 months after flight. Ventricular volume substantially increased for 1 of the 12-month astronauts (left: +25%, right: +23%) and the 6-month astronauts (left: 17 ± 12%, right: 24 ± 6%) and exhibited little recovery at 6 months. Several changes correlated with past flight experience; those with less time between subsequent missions had larger preflight ventricles and smaller ventricular volume increases with flight. This suggests that spaceflight-induced ventricular changes may endure for long periods after flight. These results provide insight into brain changes that occur with long-duration spaceflight and demonstrate the need for closer study of fluid shifts.

Secondary prevention of fragility fractures in Asia Pacific: an educational initiative

The Asia -Pacific Bone Academy (APBA) Fracture Liaison Service (FLS) Focus Group educational initiative has stimulated activity across the Asia -Pacific region with the intention of supporting widespread implementation of new FLS. In 2017, the APBA FLS Focus Group developed a suite of tools to support implementation of FLS across the Asia-Pacific region as a component of a multi-faceted educational initiative. This article puts this initiative into context with a narrative review describing the burden of fragility fractures in the region, the current secondary fracture prevention care gap and a summary of emerging best practice. The results of a survey to evaluate the impact of the APBA educational initiative is presented, in addition to commentary on recent activities intended to improve the care of individuals who sustain fragility fractures across the Asia -Pacific. A FLS Toolbox for Asia-Pacific was developed which included the following sections:1. The burden of fragility fractures in the Asia-Pacific region.2. A summary of evidence for FLS in the Asia-Pacific.3. A generic, fully referenced FLS business plan template.4. Potential cost savings accrued by each country, based on a country-specific FLS Benefits Calculator.5. How to start and expand FLS programmes in the Asia-Pacific context.6. A step-by-step guide to setting up FLS in countries in the Asia-Pacific region.7. Other practical tools to support FLS establishment.8. FLS online resources and publications.The FLS Toolbox was provided as a resource to support FLS workshops immediately following the 5th Scientific Meeting of the Asian Federation of Osteoporosis Societies (AFOS) held in Kuala Lumpur in October 2017. The FLS workshops addressed three key themes:• The FLS business case.• Planning the FLS patient pathway.• The role of the FLS coordinator in fragility fracture care management.A follow-up survey of 142 FLS workshop participants was conducted in August-September 2018. The survey included questions regarding how FLS were developed, funded, the scope of service provision and the support provided by the educational initiative. Almost one-third (30.3%) of FLS workshop participants completed the survey. Survey responses were reported for those who had established a FLS at the time the survey was conducted and, separately, for those who had not established a FLS. Findings for those who had established a FLS included:• 78.3% of respondents established a multidisciplinary team to develop the business case for their FLS.• 87.0% of respondents stated that a multidisciplinary team was established to design the patient pathway for their FLS.• 26.1% of respondents stated that their FLS has sustainable funding.• The primary source of funding for FLS was from public hospitals (83.3%) as compared with private hospitals (16.7%).Most hospitals that had not established a FLS at the time the survey was conducted were either in the process of setting-up a FLS (47%) or had plans in place to establish a FLS for which approval is being sought (29%). The primary barrier to establishing a new FLS was lack of sustainable funding. The APBA FLS Focus Group educational initiative has stimulated activity across the Asia-Pacific region with the intention of supporting widespread implementation of new FLS. A second edition of the FLS Toolbox is in development which is intended to complement ongoing efforts throughout the region to expedite widespread implementation of FLS.