Spatially confined sub-tumor microenvironments in pancreatic cancer.

Intratumoral heterogeneity is a critical frontier in understanding how the tumor microenvironment (TME) propels malignant progression. Here, we deconvolute the human pancreatic TME through large-scale integration of histology-guided regional multiOMICs with clinical data and patient-derived preclinical models. We discover "subTMEs," histologically definable tissue states anchored in fibroblast plasticity, with regional relationships to tumor immunity, subtypes, differentiation, and treatment response. "Reactive" subTMEs rich in complex but functionally coordinated fibroblast communities were immune hot and inhabited by aggressive tumor cell phenotypes. The matrix-rich "deserted" subTMEs harbored fewer activated fibroblasts and tumor-suppressive features yet were markedly chemoprotective and enriched upon chemotherapy. SubTMEs originated in fibroblast differentiation trajectories, and transitory states were notable both in single-cell transcriptomics and in situ. The intratumoral co-occurrence of subTMEs produced patient-specific phenotypic and computationally predictable heterogeneity tightly linked to malignant biology. Therefore, heterogeneity within the plentiful, notorious pancreatic TME is not random but marks fundamental tissue organizational units.

Concussion symptom presentation and clinical recovery among pediatric athletes: comparing concussions sustained during school and summer months.

OBJECTIVE: We examined post-concussion symptom presentation, exercise, and sleep among pediatric athletes who sustained concussion during the school year vs. summer months. METHODS: We evaluated athletes 6-18 years old within 21-days of concussion. They reported symptoms (Health and Behavior Inventory), with cognitive/somatic domain sub-scores calculated, and indicated if they had exercised or experienced sleep problems since injury. We grouped patients by injury season: summer months (June-August) vs. school year (September-May). RESULTS: 350 patients (14.4 ± 2.4 years old; 37% female; initial visit 8.8 ± 5.3 days post-concussion) were seen for care: 24% sustained a concussion during summer months, 76% during the school year. Lower cognitive (median = 7 [IQR = 1, 15] vs. 9.5 [4, 17]; p = 0.01), but not somatic (7 [2.5, 11] vs. 8 [4, 13]; p = 0.06), HBI scores were observed for patients injured during the summer. Groups were similar in proportion exercising (16% vs 17%) and endorsing sleep problems (29% vs 31%). After adjustments, sustaining a concussion during the summer predicted total (ß=-3.43; 95%CI = -6.50, -0.36; p = 0.029) and cognitive (ß = -2.29; 95%CI = -4.22, -0.36; p = 0.02), but not somatic (ß=-1.46; 95%CI = -2.84, -0.08; p = 0.04), symptom severity. CONCLUSION: Pediatric patients with concussion may present with greater cognitive symptoms during the school year, compared to summer months.

The Diagnostic Utility of Cervical Spine Proprioception for Adolescent Concussion.

OBJECTIVE: Cervical spine proprioception may be impaired after concussion. Our objective was to determine the diagnostic utility of cervical spine proprioception for adolescent concussion. DESIGN: Cross-sectional. SETTING: Research laboratory. PARTICIPANTS: Adolescents ≤18 days of concussion and uninjured controls. INTERVENTIONS: N/A. MAIN OUTCOMES: Head repositioning accuracy (HRA) testing, a measure of cervical spine proprioception. The HRA test involved patients relocating their head back to a neutral starting position with eyes closed after maximal cervical spine flexion, extension, and right and left rotations. The overall HRA error score was the mean error (distance from the starting point to self-reported return to neutral) across 12 trials: 3 trials in each direction. We used t-tests to compare group means and logistic regression (outcome = group, predictor = HRA, covariates) to calculate odds ratios. We used a receiver operator characteristic curve to evaluate area under the curve (AUC) and calculate the optimal HRA cutpoint to distinguish concussion from controls. RESULTS: We enrolled and tested 46 participants with concussion (age = 15.8 ± 1.3 years, 59% female, mean = 11.3 ± 3.3 days postconcussion) and 83 uninjured controls (age = 16.1 ± 1.4 years, 88% female). The concussion group had significantly worse HRA than controls (4.3 ± 1.6 vs 2.9 ± 0.7 degrees, P < 0.001, Cohen d = 1.19). The univariable HRA model AUC was 0.81 (95% CI = 0.73, 0.90). After adjusting for age, sex, and concussion history, the multivariable model AUC improved to 0.85 (95% CI = 0.77, 0.92). The model correctly classified 80% of participants as concussion/control at a 3.5-degree cutpoint. CONCLUSIONS: Adolescents with concussion demonstrated worse cervical spine proprioception than uninjured controls. Head repositioning accuracy may offer diagnostic utility for subacute concussion.

Disruption of Endosomal Sorting in Schwann Cells Leads to Defective Myelination and Endosomal Abnormalities Observed in Charcot-Marie-Tooth Disease.

Endosomal sorting plays a fundamental role in directing neural development. By altering the temporal and spatial distribution of membrane receptors, endosomes regulate signaling pathways that control the differentiation and function of neural cells. Several genes linked to inherited demyelinating peripheral neuropathies, known as Charcot-Marie-Tooth (CMT) disease, encode proteins that directly interact with components of the endosomal sorting complex required for transport (ESCRT). Our previous studies demonstrated that a point mutation in the ESCRT component hepatocyte growth-factor-regulated tyrosine kinase substrate (HGS), an endosomal scaffolding protein that identifies internalized cargo to be sorted by the endosome, causes a peripheral neuropathy in the neurodevelopmentally impaired teetering mice. Here, we constructed a Schwann cell-specific deletion of Hgs to determine the role of endosomal sorting during myelination. Inactivation of HGS in Schwann cells resulted in motor and sensory deficits, slowed nerve conduction velocities, delayed myelination and hypomyelinated axons, all of which occur in demyelinating forms of CMT. Consistent with a delay in Schwann cell maturation, HGS-deficient sciatic nerves displayed increased mRNA levels for several promyelinating genes and decreased mRNA levels for genes that serve as markers of myelinating Schwann cells. Loss of HGS also altered the abundance and activation of the ERBB2/3 receptors, which are essential for Schwann cell development. We therefore hypothesize that HGS plays a critical role in endosomal sorting of the ERBB2/3 receptors during Schwann cell maturation, which further implicates endosomal dysfunction in inherited peripheral neuropathies.SIGNIFICANCE STATEMENT Schwann cells myelinate peripheral axons, and defects in Schwann cell function cause inherited demyelinating peripheral neuropathies known as CMT. Although many CMT-linked mutations are in genes that encode putative endosomal proteins, little is known about the requirements of endosomal sorting during myelination. In this study, we demonstrate that loss of HGS disrupts the endosomal sorting pathway in Schwann cells, resulting in hypomyelination, aberrant myelin sheaths, and impairment of the ERBB2/3 receptor pathway. These findings suggest that defective endosomal trafficking of internalized cell surface receptors may be a common mechanism contributing to demyelinating CMT.

Systemic inflammatory prognostic scores in advanced pancreatic adenocarcinoma.

BACKGROUND: Systemic inflammatory scores may aid prognostication and patient selection for trials. We compared five scores in advanced pancreatic adenocarcinoma (PDAC). METHODS: Unresectable/metastatic PDAC patients enrolled in the Comprehensive Molecular Characterisation of Advanced Pancreatic Ductal Adenocarcinoma for Better Treatment Selection trial (NCT02750657) were included. Patients had pre-treatment biopsies for whole genome and RNA sequencing. CD8 immunohistochemistry was available in a subset. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, Prognostic Nutritional Index, Gustave Roussy Immune Score (GRIm-S), and Memorial Sloan Kettering Prognostic Score (MPS) were calculated. Overall survival (OS) was estimated using Kaplan-Meier methods. Associations between inflammatory scores, clinical/genomic characteristics, and OS were analysed. RESULTS: We analysed 263 patients. High-risk NLR, GRIm-S and MPS were poorly prognostic. The GRIm-S had the highest predictive ability: median OS 6.4 vs. 10 months for high risk vs. low-risk (P < 0.001); HR 2.26 (P < 0.001). ECOG ≥ 1, the basal-like subtype, and low-HRDetect were additional poor prognostic factors (P < 0.01). Inflammatory scores did not associate with RNA-based classifiers or homologous recombination repair deficiency genotypes. High-risk MPS (P = 0.04) and GRIm-S (P = 0.02) patients had lower median CD8 + tumour-infiltrating lymphocytes. CONCLUSIONS: Inflammatory scores incorporating NLR have prognostic value in advanced PDAC. Understanding immunophenotypes of poor-risk patients and using these scores in trials will advance the field.

Exercising More Than 150 min/wk After Concussion Is Associated With Sleep Quality Improvements.

OBJECTIVE: To examine whether a high volume of aerobic exercise after concussion (>150 min/wk) is associated with improved sleep quality over a 1-month period. We hypothesized that more than 150 min/wk of exercise would be associated with improved sleep quality across concussion recovery. DESIGN: Prospective cohort observational study. SETTING: Sports medicine clinic. PARTICIPANTS: Adolescents initially tested 8.4 ± 3.5 (range, 2-18) days postconcussion who returned for a follow-up assessment 34.3 ± 7.7 (range: 20-49) days postconcussion. MAIN OUTCOME MEASURES: Participants completed the Pittsburgh Sleep Quality Index and the Post-Concussion Symptom Inventory. No specific exercise or sleep recommendations were given beyond what their treating physician provided. Between study visits, participants recorded exercise performed via wrist-worn actigraphy. We calculated average exercise minutes per week and grouped participants as those who exercised more than 150 min/wk versus those who exercised 150 min/wk or less. RESULTS: Thirty-six adolescents participated. Fifteen (42%) recorded more than 150 min/wk of aerobic exercise (age = 14.0 ± 1.7 years; 47% female; mean = 5.6 ± 1.2 d/wk of exercise; mean = 49.2 ± 17.5 min/session), and 21 recorded 150 min/wk or less of aerobic exercise (age = 15.0 ± 1.9 years; 76% female; mean = 2.7 ± 1.6 d/wk of exercise; mean = 30.2 ± 7.8 min/session). There were no significant group differences in the proportion of those who self-reported beginning physical activity prior to enrollment (47% vs 33%; P = .42) or for initial sleep quality rating (8.0 ± 3.7 vs 8.6 ± 4.1; P = .67) or initial concussion symptom severity rating (34.9 ± 28.0 vs 42.6 ± 25.9; P = .40). The group that exercised more than 150 min/wk between visits demonstrated significantly greater median PSQI rating improvements than those who exercised 150 min/wk or less, with a large effect size noted (median change [interquartile range] = 5 [3, 7] vs 1 [0, 4]; P = .008; Cohen d = 0.96). CONCLUSION: Current recommendations suggest that subsymptom aerobic exercise can be beneficial after concussion. Our findings indicate that an exercise volume of more than 150 min/wk led to greater sleep quality improvements than those who exercised below this level.

Double Vision and Light Sensitivity Symptoms are Associated With Return-to-School Timing After Pediatric Concussion.

OBJECTIVE: To determine the association between academic time loss postconcussion and vision symptoms/impairments among pediatric patients. DESIGN: Cross-sectional. SETTING: Sports medicine clinic. PATIENTS: Pediatric patients seen for care in a sports medicine clinic between the ages 6 and 18 years (n = 212; mean age = 14.3, SD = 2.4 years; 48% female) were evaluated within 21 days of concussion (mean = 9.8, SD = 5.7 days). INDEPENDENT VARIABLE: Patients were grouped based on academic time loss (missed >5 days vs ≤5 days of school) at their initial postconcussion evaluation. OUTCOME MEASURES: Patients rated concussion symptoms using the Health and Behavior Inventory (HBI) and underwent near point of convergence (NPC) testing. We compared groups on specific HBI symptom ratings of dizziness, blurry vision, seeing double, and light sensitivity, as well as NPC break and recovery point distances. RESULTS: Two hundred twelve patients were included; n = 36 (17%) who reported missing >5 days of school. After adjusting for time since injury, parental education level, mechanism of injury, and preinjury anxiety, patients who reported missing >5 days of school had higher ratings of double vision (ß = 0.27; 95% confidence interval [CI], 0.01-0.53; P = 0.04) and light sensitivity (ß = 0.506; 95% CI, 0.061-0.951; P = 0.02), but not dizziness (ß = 0.390; 95% CI, -0.047 to 0.827; P = 0.08) or blurry vision (ß = 0.026; 95% CI, -0.352 to 0.404; P = 0.89). CONCLUSION: Missing >5 days of school was associated with worse double vision and light sensitivity symptoms. Given the importance of vision in learning, assessing postconcussion vision symptoms may facilitate a successful return to school. Clinicians should assess a wide spectrum of vision-specific symptoms to ensure appropriate support during the return-to-school process.

Influence of Personal and Injury-Related Factors Predicting Deficits in Quality of Life Domains Among Pediatric Athletes: Findings From the Sport Concussion Outcomes in Pediatrics Study.

OBJECTIVE: To examine patient and injury factors that may predict quality of life (QoL) and symptom duration after concussion. DESIGN: Prospective, longitudinal. SETTINGS: Six children's hospital-based medical centers and 9 secondary school athletic training facilities. PATIENTS: Pediatric patients (8-18 years) were enrolled as part of the Sport Concussion Outcomes in Pediatrics (SCOPE) study during their initial visit for a diagnosis of sport-related concussion. INTERVENTIONS: Patients completed a medical history, the Postconcussion Symptom Inventory (PCSI), and Patient-Reported Outcomes Measurement Information System Pediatric Profile-25 (PROMIS-PP). MAIN OUTCOME MEASURES: Eight predictor variables [age, sex, assessment time, loss of consciousness, amnesia and history of concussion, migraines, or attention-deficit hyperactivity disorder or (ADHD)] were assessed using regression models constructed for each dependent variable. RESULTS: A total of 244 patients (15.1 ± 2.1 years, 41% female) were enrolled (mean = 5 ± 3 days after concussion; range = 1-14 days). Female sex, later initial assessment, and presence of amnesia were associated with lower QoL scores on several domains, whereas loss of consciousness was associated with higher QoL for fatigue. A history of migraines was associated with lower peer relationship QoL. Patients who subsequently developed persisting symptoms had lower mobility scores and higher anxiety, depressive symptom, fatigue, and pain interference scores. CONCLUSIONS: Female sex, later clinic presentation, and amnesia were associated with a lower QoL related to mobility, anxiety, depressive symptoms, fatigue, and pain interference. Interestingly, previous concussion and preinjury ADHD diagnosis did not negatively impact postinjury QoL at the initial visit. Future studies should assess the influence of these factors on QoL at later postinjury time points using a concussion-specific outcomes instrument.

Patient Characteristics Predictive of Immediate and Delayed Word Recall Performance Following Adolescent Concussion.

Clinicians rely on objective concussion assessments that may be influenced by patient characteristics, creating difficulties in isolating the effect of concussion on patient function. The purpose of our study was to identify characteristics associated with performance on the Sport Concussion Assessment Tool 5th edition (SCAT5) 10-word recall test following adolescent concussion. We evaluated patients seen for care within 14 days of concussion (n=125; 15.2±1.6 years of age, range=11-18 years; 46% female; 6.9±3.4 days post-concussion). Patient demographic (age, sex, medical and concussion history, etc.), injury (timing of presentation, symptom severity, sport-type, etc.), and clinical test (Modified Balance Error Scoring System [mBESS], tandem gait) characteristics were assessed, in addition to SCAT5 immediate and delayed memory testing using the 10-word recall list. Immediate and delayed recall performance was significantly associated with concussion symptom burden and cognitive accuracy during tandem gait, although effect sizes were notably small. Specific variables such as age, sex, diagnosis of ADD/ADHD, and performance on other clinical assessments were not significantly associated with recall performance after controlling for covariates. Further, the 10-word recall list demonstrates specific advantages over previously used 5-word lists by way of decreased ceiling effects and reduced interference of inherent patient characteristics.

More Physical Activity Is Correlated With Reduction in Kinesiophobia for Adolescents With Persistent Symptoms After Concussion.

CONTEXT: The relationship between physical activity (PA) and fear of pain with movement (ie, kinesiophobia) during concussion recovery is unknown. Kinesiophobia may limit PA, while PA after concussion may reduce kinesiophobia. Our purpose was to examine the correlation between PA and self-reported kinesiophobia during concussion recovery for adolescents with and without persistent symptoms. DESIGN: Prospective cohort study of children ages 10-18 years within 14 days of concussion. METHODS: Participants rated kinesiophobia using the Tampa Scale of Kinesiophobia (TSK) at initial (≤14 d postconcussion) and return to play (RTP) assessments, and wore activity monitors between assessments. Our primary outcome was TSK score change from initial to RTP assessments. We grouped participants based on whether they experienced persistent symptoms (symptoms ≥28 days) or not (symptoms <28 days) and calculated correlation coefficients (Pearson r for normally distributed and Spearman rho for nonnormally distributed variables) between PA variables and TSK change scores. RESULTS: Among the 41 participants enrolled, 44% developed persistent symptoms (n = 18; age = 14.5 [2.0] y; 50% female; symptom duration = 57.3 [6.2] d; RTP = 66.8 [6.4] d) and 56% did not (n = 23; age = 14.9 [1.8] y; 48% female; symptom duration = 15.2 [1.5] d; RTP = 21.7 [1.9] d). For the persistent symptoms group, greater TSK change scores (mean = -2.5 [5.7] point change) were significantly and moderately correlated with higher daily step count (r = -.60, P = .008) and exercise frequency (r = -.63, P = .005), but were not correlated with exercise duration (ρ = -.12, P = .65). Among the no persistent symptoms group, TSK change scores (mean = -6.0 [5.0] point change) were not correlated with step count (r = -.18, P = .41) or exercise duration (ρ = .10, P = .67), and the correlation with frequency was low and not significant (r = -.34, P = .12). CONCLUSIONS: Regular PA during concussion recovery, regardless of duration or intensity, may help reduce kinesiophobia for those experiencing persistent symptoms.

Early Moderate to Vigorous Physical Activity After Concussion Is Associated With Faster Symptom Resolution Time.

CONTEXT: Early physical activity (PA) after concussion may promote symptom resolution. Prior studies have investigated exercise frequency/duration, yet precise PA intensity or volume required for optimal recovery requires further investigation. moderate to vigorous physical activity (MVPA) is beneficial for physical health. We investigated whether sedentary time, light activity time, MVPA time, or activity frequency in the weeks following concussion are associated with time to symptom resolution among adolescents. DESIGN: Prospective cohort study. METHODS: Adolescents 10-18 years of age were tested ≤14 days of concussion and followed until symptom resolution. At the initial visit, participants rated symptom severity and were provided wrist-worn activity trackers to monitor PA for the following week. PA behavior was categorized each day based on heart rate: sedentary (resting), light PA (50%-69% age-predicted max heart rate), and MVPA (70%-100% age-predicted max heart rate). Symptom resolution was defined as the date when participants reported cessation of concussion-like symptoms. Patients were not given specific PA instructions, though some may have received instructions from their physician. RESULTS: Fifty-four participants were included in the study (54% female; mean age = 15.0 [1.8] y; initially assessed 7.5 [3.2] d after concussion). Female athletes recorded more sedentary time (900 [46] vs 738 [185] min/d; P = .01; Cohen d = 0.72), and less time in light PA (194.7 [64.5] vs 224 [55] min/d; P = .08; Cohen d = 0.48) and MVPA (23 [17] vs 38 [31] min/d; P = .04; Cohen d = 0.58) than male athletes. After adjusting for sedentary time, hours per day with >250 steps, sex, and initial symptom severity, more MVPA time was associated with faster symptom resolution time (hazard ratio = 1.016; 95% confidence interval, 1.001-1.032; P = .04). CONCLUSION: Our findings offer preliminary insight into how varying PA intensities affect concussion recovery, as MVPA may be a higher intensity than what is typically prescribed in concussion care.

Genomic Features and Classification of Homologous Recombination Deficient Pancreatic Ductal Adenocarcinoma.

BACKGROUND AND AIMS: Homologous recombination deficiency (HRD) in pancreatic ductal adenocarcinoma (PDAC), remains poorly defined beyond germline (g) alterations in BRCA1, BRCA2, and PALB2. METHODS: We interrogated whole genome sequencing (WGS) data on 391 patients, including 49 carriers of pathogenic variants (PVs) in gBRCA and PALB2. HRD classifiers were applied to the dataset and included (1) the genomic instability score (GIS) used by Myriad's MyChoice HRD assay; (2) substitution base signature 3 (SBS3); (3) HRDetect; and (4) structural variant (SV) burden. Clinical outcomes and responses to chemotherapy were correlated with HRD status. RESULTS: Biallelic tumor inactivation of gBRCA or PALB2 was evident in 43 of 49 germline carriers identifying HRD-PDAC. HRDetect (score ≥0.7) predicted gBRCA1/PALB2 deficiency with highest sensitivity (98%) and specificity (100%). HRD genomic tumor classifiers suggested that 7% to 10% of PDACs that do not harbor gBRCA/PALB2 have features of HRD. Of the somatic HRDetecthi cases, 69% were attributed to alterations in BRCA1/2, PALB2, RAD51C/D, and XRCC2, and a tandem duplicator phenotype. TP53 loss was more common in BRCA1- compared with BRCA2-associated HRD-PDAC. HRD status was not prognostic in resected PDAC; however in advanced disease the GIS (P = .02), SBS3 (P = .03), and HRDetect score (P = .005) were predictive of platinum response and superior survival. PVs in gATM (n = 6) or gCHEK2 (n = 2) did not result in HRD-PDAC by any of the classifiers. In 4 patients, BRCA2 reversion mutations associated with platinum resistance. CONCLUSIONS: Germline and parallel somatic profiling of PDAC outperforms germline testing alone in identifying HRD-PDAC. An additional 7% to 10% of patients without gBRCA/PALB2 mutations may benefit from DNA damage response agents.

Is Biannual Surveillance for Pancreatic Cancer Sufficient in Individuals With Genetic Syndromes or Familial Pancreatic Cancer?

BACKGROUND: Individuals with a family history of pancreatic adenocarcinoma (PC) or with a germline mutation in a PC susceptibility gene are at increased risk of developing PC. These high-risk individuals (HRIs) may benefit from PC surveillance. METHODS: A PC surveillance program was developed to evaluate the detection of premalignant lesions and early-stage PCs using biannual imaging and to determine whether locally advanced or metastatic PCs develop despite biannual surveillance. From January 2013 to April 2020, asymptomatic HRIs were enrolled and followed with alternating MRI and endoscopic ultrasound every 6 months. RESULTS: Of 75 HRIs, 43 (57.3%) had a germline mutation in a PC susceptibility gene and 32 (42.7%) had a familial pancreatic cancer (FPC) pedigree. Branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) were identified in 26 individuals (34.7%), but only 2 developed progressive lesions. One patient with Peutz-Jeghers syndrome (PJS) developed locally advanced PC arising from a BD-IPMN. Whole-genome sequencing of this patient's PC and of a second patient with PJS-associated PC from the same kindred revealed biallelic inactivation of STK11 in a KRAS-independent manner. A review of 3,853 patients from 2 PC registries identified an additional patient with PJS-associated PC. All 3 patients with PJS developed advanced PC consistent with the malignant transformation of an underlying BD-IPMN in <6 months. The other surveillance patient with a progressive lesion had FPC and underwent resection of a mixed-type IPMN that harbored polyclonal KRAS mutations. CONCLUSIONS: PC surveillance identifies a high prevalence of BD-IPMNs in HRIs. Patients with PJS with BD-IPMNs may be at risk for accelerated malignant transformation.

Correlation of transcriptional subtypes with a validated CT radiomics score in resectable pancreatic ductal adenocarcinoma.

OBJECTIVES: Transcriptional classifiers (Bailey, Moffitt and Collison) are key prognostic factors of pancreatic ductal adenocarcinoma (PDAC). Among these classifiers, the squamous, basal-like, and quasimesenchymal subtypes overlap and have inferior survival. Currently, only an invasive biopsy can determine these subtypes, possibly resulting in treatment delay. This study aimed to investigate the association between transcriptional subtypes and an externally validated preoperative CT-based radiomic prognostic score (Rad-score). METHODS: We retrospectively evaluated 122 patients who underwent resection for PDAC. All treatment decisions were determined at multidisciplinary tumor boards. Tumor Rad-score values from preoperative CT were dichotomized into high or llow categories. The primary endpoint was the correlation between the transcriptional subtypes and the Rad-score using multivariable linear regression, adjusting for clinical and histopathological variables (i.e., tumor size). Prediction of overall survival (OS) was secondary endpoint. RESULTS: The Bailey transcriptional classifier significantly associated with the Rad-score (coefficient = 0.31, 95% confidence interval [CI]: 0.13-0.44, p = 0.001). Squamous subtype was associated with high Rad-scores while non-squamous subtype was associated with low Rad-scores (adjusted p = 0.03). Squamous subtype and high Rad-score were both prognostic for OS at multivariable analysis with hazard ratios (HR) of 2.79 (95% CI: 1.12-6.92, p = 0.03) and 4.03 (95% CI: 1.42-11.39, p = 0.01), respectively. CONCLUSIONS: In patients with resectable PDAC, an externally validated prognostic radiomic model derived from preoperative CT is associated with the Bailey transcriptional classifier. Higher Rad-scores were correlated with the squamous subtype, while lower Rad-scores were associated with the less lethal subtypes (immunogenic, ADEX, pancreatic progenitor). KEY POINTS: • The transcriptional subtypes of PDAC have been shown to have prognostic importance but they require invasive biopsy to be assessed. • The Rad-score radiomic biomarker, which is obtained non-invasively from preoperative CT, correlates with the Bailey squamous transcriptional subtype and both are negative prognostic biomarkers. • The Rad-score is a promising non-invasive imaging biomarker for personalizing neoadjuvant approaches in patients undergoing resection for PDAC, although additional validation studies are required.

A renewed model of pancreatic cancer evolution based on genomic rearrangement patterns.

Pancreatic cancer, a highly aggressive tumour type with uniformly poor prognosis, exemplifies the classically held view of stepwise cancer development. The current model of tumorigenesis, based on analyses of precursor lesions, termed pancreatic intraepithelial neoplasm (PanINs) lesions, makes two predictions: first, that pancreatic cancer develops through a particular sequence of genetic alterations (KRAS, followed by CDKN2A, then TP53 and SMAD4); and second, that the evolutionary trajectory of pancreatic cancer progression is gradual because each alteration is acquired independently. A shortcoming of this model is that clonally expanded precursor lesions do not always belong to the tumour lineage, indicating that the evolutionary trajectory of the tumour lineage and precursor lesions can be divergent. This prevailing model of tumorigenesis has contributed to the clinical notion that pancreatic cancer evolves slowly and presents at a late stage. However, the propensity for this disease to rapidly metastasize and the inability to improve patient outcomes, despite efforts aimed at early detection, suggest that pancreatic cancer progression is not gradual. Here, using newly developed informatics tools, we tracked changes in DNA copy number and their associated rearrangements in tumour-enriched genomes and found that pancreatic cancer tumorigenesis is neither gradual nor follows the accepted mutation order. Two-thirds of tumours harbour complex rearrangement patterns associated with mitotic errors, consistent with punctuated equilibrium as the principal evolutionary trajectory. In a subset of cases, the consequence of such errors is the simultaneous, rather than sequential, knockout of canonical preneoplastic genetic drivers that are likely to set-off invasive cancer growth. These findings challenge the current progression model of pancreatic cancer and provide insights into the mutational processes that give rise to these aggressive tumours.

Dizziness Is Associated With Neck/Shoulder Pain Following Pediatric Concussion.

OBJECTIVE: To examine the association between dizziness and neck/shoulder pain after concussion and if differences in postural stability and oculomotor function exist among patients reporting dizziness with or without concurrent neck/shoulder pain. DESIGN: Cross sectional. SETTING: Sports medicine clinic. PATIENTS: Pediatric patients ≤14 days post concussion. INTERVENTIONS: N/A. OUTCOME MEASURES: Patients completed the Health and Behavior Inventory (HBI) symptom rating and separately rated neck/shoulder pain (scale 0-3; 0 = no pain). We grouped patients by HBI dizziness rating (0 = not-dizzy; 1-3 = dizzy) and compared neck/shoulder pain ratings between the groups. We then compared oculomotor and postural stability outcomes between dizzy patients with and without neck/shoulder pain. RESULTS: We included 153 patients: dizzy (n = 100; age = 14.6 ± 2.2 years; 48% female) and not-dizzy (n = 53, age = 14.4 ± 3.1 years; 38% female). The dizzy group reported significantly higher neck/shoulder pain (1.4 ± 1.1 vs 0.5 ± 0.9 points, P < 0.001) and total symptom score (25.7 ± 11.2 vs 11.7 ± 9.3 points, P < 0.001) than the not-dizzy group. After adjusting for total symptom score and preinjury anxiety, depression, and migraines, dizziness was associated with higher odds of neck/shoulder pain (odds ratio = 1.9, 95% CI, 1.2-3.0; P = 0.004). No differences were observed between dizzy patients with and without neck/shoulder pain for near point of convergence (10.0 ± 7.5 vs 8.5 ± 6.7 cm, P = 0.43), modified Balance Error Scoring System (8.9 ± 5.5 vs 6.8 ± 4.7 errors, P = 0.09), or tandem gait (single-task: 26.0 ± 12.3 vs 24.2 ± 11.9 seconds, P = 0.56; dual-task: 35.1 ± 14.3 vs 35.6 ± 18.6 seconds, P = 0.90). CONCLUSIONS: In concussion patients experiencing dizziness, evaluating neck/shoulder pain may help identify individuals who would benefit from cervical spine rehabilitation. However, other potential causes of dizziness should also be evaluated to facilitate timely recovery.

Clinical and genomic characterisation of mismatch repair deficient pancreatic adenocarcinoma.

OBJECTIVE: To describe the clinical, pathological and genomic characteristics of pancreatic cancer with DNA mismatch repair deficiency (MMRD) and proficiency (MMRP). DESIGN: We identified patients with MMRD and MMRP pancreatic cancer in a clinical cohort (N=1213, 519 with genetic testing, 53 with immunohistochemistry (IHC)) and a genomic cohort (N=288 with whole-genome sequencing (WGS)). RESULTS: 12 out of 1213 (1.0%) in the clinical cohort were MMRD by IHC or WGS. Of the 14 patients with Lynch syndrome, 3 (21.4%) had an MMRP pancreatic cancer by IHC, and 4 (28.6%) were excluded because tissue was unavailable for testing. MMRD cancers had longer overall survival after surgery (weighted HR after coarsened exact matching 0.11, 95% CI 0.02 to 0.78, p=0.001). One patient with an unresectable MMRD cancer has an ongoing partial response 3 years after starting treatment with PD-L1/CTLA-4 inhibition. This tumour showed none of the classical histopathological features of MMRD. 9 out of 288 (3.1%) tumours with WGS were MMRD. Despite markedly higher tumour mutational burden and neoantigen loads, MMRD cancers were significantly less likely to have mutations in usual pancreatic cancer driver genes like KRAS and SMAD4, but more likely to have mutations in genes that drive cancers with microsatellite instability like ACV2RA and JAK1. MMRD tumours were significantly more likely to have a basal-like transcriptional programme and elevated transcriptional markers of immunogenicity. CONCLUSIONS: MMRD pancreatic cancers have distinct clinical, pathological and genomic profiles. Patients with MMRD pancreatic cancer should be considered for basket trials targeting enhanced immunogenicity or the unique genomic drivers in these malignancies.

Examination of genetic and pharmacological tools to study the proteasomal deubiquitinating enzyme ubiquitin-specific protease 14 in the nervous system.

Strategies for enhancing protein degradation have been proposed for treating neurological diseases associated with a decline in proteasome activity. A proteasomal deubiquitinating enzyme that controls substrate entry into proteasomes, ubiquitin-specific protease 14 (USP14), is an attractive candidate for therapies that modulate proteasome activity. This report tests the validity of genetic and pharmacological tools to study USP14's role in regulating protein abundance. Although previous studies implicated USP14 in the degradation of microtubule associate protein tau, tar DNA binding protein, and prion protein, the levels of these proteins were similar in our neurons cultured from wild type and USP14-deficient mice. Neither loss nor over-expression of USP14 affected the levels of these proteins in mice, implying that modifying the amount of USP14 is not sufficient to alter their steady-state levels. However, neuronal over-expression of a catalytic mutant of USP14 showed that manipulating USP14's ubiquitin-hydrolase activity altered the levels of specific proteins in vivo. Although pharmacological inhibitors of USP14's ubiquitin-hydrolase activity reduced microtubule associate protein tau, tar DNA binding protein, and prion protein in culture, the effect was similar in wild type and USP14-deficient neurons, thus impacting their use for specifically evaluating USP14 in a therapeutic manner. While examining how targeting USP14 may affect other proteins in vivo, this report showed that fatty acid synthase, v-rel reticuloendotheliosis viral oncogene homolog, CTNNB1, and synaptosome associated protein 23 are reduced in USP14-deficient mice; however, loss of USP14 differentially altered the levels of these proteins in the liver and brain. As such, it is critical to more thoroughly examine how inhibiting USP14 alters protein abundance to determine if targeting USP14 will be a beneficial strategy for treating neurodegenerative diseases.

Isometric Cervical Muscular Strength in Pediatric Athletes With Multiple Concussions.

OBJECTIVE: To compare maximal cervical muscle strength among athletes with a history of 2 or more concussions relative to athletes with no history of a previous concussion. DESIGN: Athletes in the 2 groups were frequency-matched. Linear mixed models were used to test for differences in peak isometric flexion, extension, left lateral flexion, and right lateral flexion cervical muscle torque between groups. SETTING: Pediatric sports medicine clinic. PARTICIPANTS: Athletes with a history of multiple concussions (n = 16) and athletes with no previous concussion history (n = 17). INTERVENTIONS (OR ASSESSMENT OF RISK FACTORS OR INDEPENDENT VARIABLES):: Concussion history (group), age, sex, neck girth, and height. MAIN OUTCOME MEASURES: Peak isometric torque measured with a stationary isokinetic dynamometer during a 3-second isometric hold. RESULTS: There was no significant difference in peak flexion [mean difference: 21.2%, 95% confidence interval (CI): -6.6% to 57.4%, P = 0.1413], extension (mean difference: 17%, 95% CI, -6.8% to 47.1%, P = 0.1667), left lateral (mean difference: 4.4%, 95% CI, -16.9% to 31.1%, P = 0.7011), or right lateral (mean difference: 9.3%, 95% CI, -14.5% to 39.8%, P = 0.4627) isometric torque in the concussion group relative to the control group. Across all muscle actions, neck torque was significantly (P < 0.05) higher in male compared with female athletes. Increasing neck girth was also associated with a significant (P < 0.05) increase in neck torque. CONCLUSIONS: There was no evidence of a consistent cervical muscle strength deficit among athletes with a history of 2 or more concussions relative to athletes with no previous history of a concussion. Age, neck girth, and sex were significantly associated with cervical muscle strength. CLINICAL RELEVANCE: Isometric cervical muscle strength testing may not be a reliable test for differentiating athletes with a history of multiple concussions relative to athletes with no history of concussions in the pediatric and adolescent population. Our study presents a reliable methodology for testing cervical muscle strength among young athletes.

Sleep Problems and Melatonin Prescription After Concussion Among Youth Athletes.

OBJECTIVES: To examine the effect of sleep disturbances on concussion symptom recovery and to examine the effect of melatonin prescription on symptom improvement among concussed adolescents with sleep problems. DESIGN: Longitudinal test-retest. SETTING: Sports medicine clinic. PARTICIPANTS: Patients aged 8 to 18 years, diagnosed with a concussion, evaluated within 14 days after injury, and evaluated again 15 to 35 days after injury. INDEPENDENT VARIABLES: We grouped patients based on whether they reported sleep disturbances within 14 days of injury. MAIN OUTCOME MEASURES: Outcome measures included symptom severity, headache severity, melatonin prescription, and the change in symptom severity between visits. RESULTS: Two hundred twenty-five patients were included: 36% who reported sleep problems (44% female; age = 14.4 ± 2.0 years; evaluated 7.3 ± 3.8 and 23.2 ± 5.4 days after injury) and 64% who did not (32% female; age = 14.6 ± 2.3 years; evaluated 7.2 ± 3.4 and 23.0 ± 5.3 days after injury). Those with sleep problems reported higher symptom severity than those without across the 2 visits (22.1 ± 14.3 vs 14.6 ± 12.5; P < 0.001). There was no significant difference in the change in symptom severity between visits among those who received [median = 9-point improvement; interquartile range (IQR) = 1-14] and did not (median = 9, IQR = 2-18) receive a melatonin prescription (P = 0.80). CONCLUSIONS: Sleep problems among pediatric patients within 2 weeks of concussion are associated with more severe symptoms. Melatonin prescription was not associated with faster symptom recovery.