Unstructured linker regions play a role in the differential splicing activities of paralogous RNA binding proteins PTBP1 and PTBP2

RNA Binding Proteins regulate, in part, alternative pre-mRNA splicing and, in turn, gene expression patterns. Polypyrimidine tract binding proteins PTBP1 and PTBP2 are paralogous RNA binding proteins sharing 74% amino acid sequence identity. Both proteins contain four structured RNA-recognition motifs (RRMs) connected by linker regions and an N-terminal region. Despite their similarities, the paralogs have distinct tissue-specific expression patterns and can regulate discrete sets of target exons. How two highly structurally similar proteins can exert different splicing outcomes is not well understood. Previous studies revealed that PTBP2 is post-translationally phosphorylated in the unstructured N-terminal, Linker 1, and Linker 2 regions that share less sequence identity with PTBP1 signifying a role for these regions in dictating the paralog's distinct splicing activities. To this end, we conducted bioinformatics analysis to determine the evolutionary conservation of RRMs versus linker regions in PTBP1 and PTBP2 across species. To determine the role of PTBP2 unstructured regions in splicing activity, we created hybrid PTBP1-PTBP2 constructs that had counterpart PTBP1 regions swapped to an otherwise PTBP2 protein and assayed on differentially regulated exons. We also conducted molecular dynamics studies to investigate how negative charges introduced by phosphorylation in PTBP2 unstructured regions can alter their physical properties. Collectively, results from our studies reveal an important role for PTBP2 unstructured regions and suggest a role for phosphorylation in the differential splicing activities of the paralogs on certain regulated exons.

Does Tibial Tuberosity Osteotomy Improve Outcomes When Combined With Medial Patellofemoral Ligament Reconstruction in the Presence of Increased Tibial Tuberosity-Trochlear Groove Distance? A Systematic Review and Meta-analysis

Background

There has been recent debate regarding the optimal surgical management strategy for recurrent patellofemoral instability in the presence of an increased tibial tuberosity-trochlear groove (TT-TG) distance. In particular, performing a combined tibial tuberosity osteotomy (TTO) and medial patellofemoral ligament reconstruction (MPFLR) for patients with a TT-TG >20 mm has been questioned, with the hypothesis that an isolated MPFLR (iMPFLR) would be just as effective.

Purpose

To pool and compare outcomes after MPFLR+TTO versus iMPFLR in patients with a TT-TG >20 mm.

Study Design

Systematic review; Level of evidence, 4.

Methods

PubMed-MEDLINE, Embase, Web of Science, and Cochrane Central were searched, and a systematic review was performed. Included were studies that reported postoperative redislocation rates and/or functional outcome scores for patients with recurrent patellar instability and a TT-TG >20 mm who underwent either MPFLR+TTO or iMPFLR and had minimum 2-year follow-up data. Methodologic quality was assessed using the modified Coleman Methodology Score (mCMS). A proportional meta-analysis comparing redislocation, subjective instability, and total complication rates was performed, and mean postoperative functional outcome scores were pooled using a random-effects model with a restricted maximum likelihood estimator.

Results

In total, 1548 studies were screened, from which 13 were included for analysis. Of the 386 included patients (406 knees), 276 underwent MPFLR+TTO and 110 underwent iMPFLR. The mean mCMS was 61.3 ± 10.5 (range, 48-77). The pooled postoperative redislocation rate was 1.22% (95% CI, 0.22%-7%), with no significant difference between the study groups (P = .9995). The pooled complication rate was 10.17% (95% CI, 6.2%-16.3%) with no difference between groups (P = .9275), although the MPFLR+TTO group had higher heterogeneity in complication rates (I2 = 79.4%) compared with iMPFLR (I2 = 0%). There was no group difference in the pooled postoperative Lysholm scores (P = .5177), but patients who underwent iMPFLR had significantly higher postoperative Kujala scores compared with those who underwent MPFLR+TTO (P = .0283).

Conclusion

Even in the presence of previously indicative anatomic factors (TT-TG >20 mm), TTO combined with MPFLR does not seem to confer additional benefit compared with iMPFLR. This finding could be advantageous in minimizing the burden of additional surgery with its associated risks. The study findings should, however, be interpreted with caution given the heterogeneity of the studies.

Development of an age- and comorbidity- adjusted optimal radiotherapy utilisation rate for lung, rectal, prostate and cervical cancers

INTRODUCTION

Optimal radiotherapy utilisation (RTU) modelling estimates the proportion of people with cancer who would benefit from radiotherapy. Assessment of comorbidities is an important component of the assessment of suitability for radiotherapy in addition to chronological age and life expectancy. Comorbidities have not been considered in previous optimal RTU models. We aimed to develop an age- and comorbidity- adjusted optimal RTU model for patients with lung, rectal, prostate, and cervical cancer, and compare them to actual RTU rates, with a particular focus on those aged 80+ years, METHODS: New South Wales (NSW) Cancer Registry data (2010-2014) linked to radiotherapy data (2010-2015) and hospitalisation data (2008-2015) were used to determine the number of patients diagnosed with lung, rectal, prostate and cervical cancer. The Cancer Specific C3 'all sites' comorbidity index was calculated from hospital diagnosis data for each patient to determine suitability for radiotherapy. The index was then incorporated into a tumour site-specific decision tree model. The actual RTU was also calculated using the linked datasets.

RESULTS

14,696 patients were diagnosed with non-small cell lung cancer (NSCLC), 1839 with small cell lung cancer (SCLC), 5551 with rectal cancer, 30,935 with prostate cancer and 1216 with cervical cancer in New South Wales from 2010-2014. The proportion of patients aged 80+ years at cancer diagnosis was 25% (3603 patients), 15% (279 patients), 17% (943 patients), 12% (3745 patients), and 7% (88 patients) respectively. The age- and comorbidity- adjusted optimal RTU rates for patients aged 80+ years using the C3 index were 49% (NSCLC), 49% (SCLC), 43% (rectal), 51% (prostate) and 40% (cervical). The corresponding actual RTU rates for patients aged 80+ years were 25%, 32%, 27%, 16%, and 56%.

CONCLUSION

Even after adjusting for age and comorbidities, the actual radiotherapy utilisation rates were lower than optimal radiotherapy utilisation rates in patients aged 80+ years except for patients with cervical cancer. This warrants further assessment and research into reasons and solutions.

Diffusive fluxes of persistent organic pollutants between Arctic atmosphere, surface waters and sediments

Arctic communities are disproportionately exposed to pollutants from sources including global atmospheric transport and formerly used defense sites (FUDS). The effects of climate change and increasing development in the Arctic have the potential to exacerbate this problem. Yupik People of Sivuqaq, or St Lawrence Island, Alaska are one such community with documented exposures to pollutants from FUDS, and their traditional lipid-rich foods such as blubber and rendered oils of marine mammals. Troutman Lake, adjacent to the Yupik community of Gambell, Alaska, was used as a disposal site during the decommission of the adjacent FUDS, leading to community concern about exposure to military pollution and intrusion from historic local dump sites. In collaboration with a local community group, this study utilized passive sampling devices deployed in Troutman Lake. Air, water and sediment deployed samplers were analyzed for unsubstituted and alkylated polycyclic aromatic hydrocarbons (PAHs), brominated and organophosphate flame retardants and polychlorinated biphenyls (PCBs). PAH concentrations were low and comparable to other remote/rural locations. PAHs were generally in deposition from the overlying atmosphere into Troutman Lake. Of the flame retardants, brominated diphenyl ether-47 was detected in all surface water samplers while triphenyl phosphate was detected in all environmental compartments. Both were at concentrations equivalent or lower than other remote locations. Of particular interest, we measured higher atmospheric concentrations of tris(2-chloroethyl) phosphate (TCEP) (0.75-2.8 ng/m3) than previously reported in the literature for remote Arctic sites (<0.017-0.56 ng/m3). TCEP was found to be in deposition to Troutman Lake at magnitudes from 290 to 1300 ng/m2/day. No PCBs were detected in this study. Our findings demonstrate the relevance of both modern and legacy chemicals from local and global sources. These results help us to understand the fate of anthropogenic contaminants in dynamic Arctic systems providing valuable data for communities, policy makers and scientists.

Integrating participant feedback and concerns to improve community and individual level chemical exposure assessment reports

BACKGROUND

As exposure assessment has shifted towards community-engaged research there has been an increasing trend towards reporting results to participants. Reports aim to increase environmental health literacy, but this can be challenging due to the many unknowns regarding chemical exposure and human health effects. This includes when reports encompass a wide-range of chemicals, limited reference or health standards exist for those chemicals, and/or incompatibility of data generated from exposure assessment tools with published reference values (e.g., comparing a wristband concentration to an oral reference dose).

METHODS

Houston Hurricane Harvey Health (Houston-3H) participants wore silicone wristbands that were analyzed for 1,530 organic compounds at two time-points surrounding Hurricane Harvey. Three focus groups were conducted in separate neighborhoods in the Houston metropolitan area to evaluate response to prototype community and individual level report-backs. Participants (n = 31) evaluated prototype drafts using Likert scales and discussion prompts. Focus groups were audio-recorded, and transcripts were analyzed using a qualitative data analysis program for common themes, and quantitative data (ranking, Likert scales) were statistically analyzed.

RESULTS

Four main themes emerged from analysis of the transcripts: (1) views on the report layout; (2) expression of concern over how chemicals might impact their individual or community health; (3) participants emotional response towards the researchers; and (4) participants ability to comprehend and evaluate environmental health information. Evaluation of the report and key concerns differed across the three focus groups. However, there was agreement amongst the focus groups about the desire to obtain personal exposure results despite the uncertainty of what the participant results meant.

CONCLUSIONS

The report-back of research results (RBRR) for community and individual level exposure assessment data should keep the following key principles in mind: materials should be accessible (language level, data visualization options, graph literacy), identify known information vs unknown (e.g., provide context for what exposure assessment data means, acknowledge lack of current health standards or guidelines), recognize and respect community knowledge and history, and set participant expectations for what they can expect from the report.

Automated detection, delineation and quantification of whole-body bone metastasis using FDG-PET/CT images

Non-small cell lung cancer (NSCLC) patients with the metastatic spread of disease to the bone have high morbidity and mortality. Stereotactic ablative body radiotherapy increases the progression free survival and overall survival of these patients with oligometastases. FDG-PET/CT, a functional imaging technique combining positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) and computer tomography (CT) provides improved staging and identification of treatment response. It is also associated with reduction in size of the radiotherapy tumour volume delineation compared with CT based contouring in radiotherapy, thus allowing for dose escalation to the target volume with lower doses to the surrounding organs at risk. FDG-PET/CT is increasingly being used for the clinical management of NSCLC patients undergoing radiotherapy and has shown high sensitivity and specificity for the detection of bone metastases in these patients. Here, we present a software tool for detection, delineation and quantification of bone metastases using FDG-PET/CT images. The tool extracts standardised uptake values (SUV) from FDG-PET images for auto-segmentation of bone lesions and calculates volume of each lesion and associated mean and maximum SUV. The tool also allows automatic statistical validation of the auto-segmented bone lesions against the manual contours of a radiation oncologist. A retrospective review of FDG-PET/CT scans of more than 30 candidate NSCLC patients was performed and nine patients with one or more metastatic bone lesions were selected for the present study. The SUV threshold prediction model was designed by splitting the cohort of patients into a subset of 'development' and 'validation' cohorts. The development cohort yielded an optimum SUV threshold of 3.0 for automatic detection of bone metastases using FDG-PET/CT images. The validity of the derived optimum SUV threshold on the validation cohort demonstrated that auto-segmented and manually contoured bone lesions showed strong concordance for volume of bone lesion (r = 0.993) and number of detected lesions (r = 0.996). The tool has various applications in radiotherapy, including but not limited to studies determining optimum SUV threshold for accurate and standardised delineation of bone lesions and in scientific studies utilising large patient populations for instance for investigation of the number of metastatic lesions that can be treated safety with an ablative dose of radiotherapy without exceeding the normal tissue toxicity.

The Superfund Research Program Analytics Portal: linking environmental chemical exposure to biological phenotypes

The OSU/PNNL Superfund Research Program (SRP) represents a longstanding collaboration to quantify Polycyclic Aromatic Hydrocarbons (PAHs) at various superfund sites in the Pacific Northwest and assess their potential impact on human health. To link the chemical measurements to biological activity, we describe the use of the zebrafish as a high-throughput developmental toxicity model that provides quantitative measurements of the exposure to chemicals. Toward this end, we have linked over 150 PAHs found at Superfund sites to the effect of these same chemicals in zebrafish, creating a rich dataset that links environmental exposure to biological response. To quantify this response, we have implemented a dose-response modelling pipeline to calculate benchmark dose parameters which enable potency comparison across over 500 chemicals and 12 of the phenotypes measured in zebrafish. We provide a rich dataset for download and analysis as well as a web portal that provides public access to this dataset via an interactive web site designed to support exploration and re-use of these data by the scientific community at http://srp.pnnl.gov .

Racial Equity in Healthcare Machine Learning: Illustrating Bias in Models With Minimal Bias Mitigation

Background and objective While the potential of machine learning (ML) in healthcare to positively impact human health continues to grow, the potential for inequity in these methods must be assessed. In this study, we aimed to evaluate the presence of racial bias when five of the most common ML algorithms are used to create models with minimal processing to reduce racial bias. Methods By utilizing a CDC public database, we constructed models for the prediction of healthcare access (binary variable). Using area under the curve (AUC) as our performance metric, we calculated race-specific performance comparisons for each ML algorithm. We bootstrapped our entire analysis 20 times to produce confidence intervals for our AUC performance metrics. Results With the exception of only a few cases, we found that the performance for the White group was, in general, significantly higher than that of the other racial groups across all ML algorithms. Additionally, we found that the most accurate algorithm in our modeling was Extreme Gradient Boosting (XGBoost) followed by random forest, naive Bayes, support vector machine (SVM), and k-nearest neighbors (KNN). Conclusion Our study illustrates the predictive perils of incorporating minimal racial bias mitigation in ML models, resulting in predictive disparities by race. This is particularly concerning in the setting of evidence for limited bias mitigation in healthcare-related ML. There needs to be more conversation, research, and guidelines surrounding methods for racial bias assessment and mitigation in healthcare-related ML models, both those currently used and those in development.

Molecular Dynamics Simulations of the Cardiac Ryanodine Receptor Type 2 (RyR2) Gating Mechanism

Mutations in the cardiac ryanodine receptor type 2 (RyR2) have been linked to fatal cardiac arrhythmias such as catecholaminergic polymorphic ventricular tachycardia (CPVT). While many CPVT mutations are associated with an increase in Ca²⁺ leak from the sarcoplasmic reticulum, the mechanistic details of RyR2 channel gating are not well understood, and this poses a barrier in the development of new pharmacological treatments. To address this, we explore the gating mechanism of the RyR2 using molecular dynamics (MD) simulations. We test the effect of changing the conformation of certain structural elements by constructing chimera RyR2 structures that are derived from the currently available closed and open cryo-electron microscopy (cryo-EM) structures, and we then use MD simulations to relax the system. Our key finding is that the position of the S4-S5 linker (S4S5L) on a single subunit can determine whether the channel as a whole is open or closed. Our analysis reveals that the position of the S4S5L is regulated by interactions with the U-motif on the same subunit and with the S6 helix on an adjacent subunit. We find that, in general, channel gating is crucially dependent on high percent occupancy interactions between adjacent subunits. We compare our interaction analysis to 49 CPVT1 mutations in the literature and find that 73% appear near a high percent occupancy interaction between adjacent subunits. This suggests that disruption of cooperative, high percent occupancy interactions between adjacent subunits is a primary cause of channel leak and CPVT in mutant RyR2 channels.

Radiotherapy utilisation rates for patients with cancer as a function of age: A systematic review

INTRODUCTION

There is an increasing incidence of cancer in older people, but limited data on radiotherapy uptake, and in particular, radiotherapy utilisation (RTU) rates. The RTU rate for older adults with cancer may be lower than recommended due to lower tolerance for radiotherapy as well as additional comorbidities, reduced life expectancy and travel for treatment. Radiotherapy use must be aligned with best available, age-specific evidence to ensure older adults with cancer receive optimal benefit without harms.

MATERIALS AND METHODS

A systematic review was conducted to synthesise the published data on the actual RTU rate for patients with cancer as a function of age. MEDLINE and EMBASE were systematically searched to identify relevant population-based and hospital-based cohort studies on radiotherapy utilisation for all age groups, published in English, from 1 January 1990 to 1 July 2020. We focused on the following common cancers in older adults for which radiotherapy is recommended: breast, prostate, lung, rectal cancer, glioblastoma multiforme (GBM), and cervical cancer. Age-specific radiotherapy utilisation data were extracted and analysed as a narrative synthesis.

RESULTS

From 2606 studies screened, 75 cohort and population-based studies were identified with age-specific radiotherapy utilisation data. The total number of patients in the 75 studies was 4,792,138. The RTU rate decreased with increasing age for all tumour sites analysed, except for patients receiving curative radiotherapy as definitive treatment for prostate or cervical cancer. This reduction with increasing age was demonstrated in both palliative and curative settings.

DISCUSSION

There is a global reduction in radiotherapy utilisation with increasing age for most tumour sites. The reduction in delivery of radiotherapy warrants further examination and evidence-based guidelines specific to this population.

Development of an age- and comorbidity adjusted- optimal radiotherapy utilisation rate for women with breast cancer

INTRODUCTION

Optimal radiotherapy utilisation (RTU) modelling estimates the proportion of people with cancer who would benefit from radiotherapy. Older adults with cancer may have comorbidities that can impact physiological reserve and affect radiotherapy recommendations. These have not been considered in previous models. We aimed to develop an age- and comorbidity-adjusted optimal RTU model for breast cancer.

METHODS

New South Wales (NSW) Cancer Registry data (2010-2014) linked to radiotherapy data (2010-2015) and hospitalisation data (2008-2015) was used to determine the number of women diagnosed with invasive breast cancer in four pre-specified age groups. The Charlson Comorbidity Index (CCI), Cancer-Specific C3 'all sites' index and the Hospital Frailty Risk Score (HFRS) were derived for each woman from diagnostic codes in hospital records. Women were deemed unfit, and thus unsuitable candidates for radiotherapy, if the comorbidity indices were as follows: CCI ≥2; C3 score ≥ 3; and HFRS ≥5. The proportions of women suitable for radiotherapy in each age group were then incorporated into a breast cancer decision tree model. The actual RTU was also calculated using the linked datasets.

RESULTS

23,601 women were diagnosed with breast cancer in NSW from 2010 to 2014 and 2526 were aged 80+ years. The overall comorbidity adjusted- RTU for women of all ages was 85·9% (CCI), 83·7% (C3) and 81·9% (HFRS). The optimal comorbidity adjusted- RTU for women aged 80+ was 76·1% (CCI), 70·1% (C3) and 61·8% (HFRS). The actual RTU for women aged 80+ years was 24.7%.

CONCLUSION

The vast majority of older Australian women with breast cancer are fit for radiotherapy. The overall optimal RTU is only slightly reduced when adjusted for age and comorbidities and was similar using each of the three indices examined. Our data suggest radiotherapy is markedly underutilised for older women with breast cancer.

Impact of acute temperature and air pollution exposures on adult lung function: A panel study of asthmatics

Background

Individuals with respiratory conditions, such as asthma, are particularly susceptible to adverse health effects associated with higher levels of ambient air pollution and temperature. This study evaluates whether hourly levels of fine particulate matter (PM_2.5) and dry bulb globe temperature (DBGT) are associated with the lung function of adult participants with asthma.

Methods and findings

Global positioning system (GPS) location, respiratory function (measured as forced expiratory volume at 1 second (FEV₁)), and self-reports of asthma medication usage and symptoms were collected as part of the Exposure, Location, and Lung Function (ELF) study. Hourly ambient PM_2.5 and DBGT exposures were estimated by integrating air quality and temperature public records with time-activity patterns using GPS coordinates for each participant (n = 35). The relationships between acute PM_2.5, DBGT, rescue bronchodilator use, and lung function collected in one week periods and over two seasons (summer/winter) were analyzed by multivariate regression, using different exposure time frames.

In separate models, increasing levels in PM_2.5, but not DBGT, were associated with rescue bronchodilator use. Conversely DBGT, but not PM_2.5, had a significant association with FEV₁. When DBGT and PM_2.5 exposures were placed in the same model, the strongest association between cumulative PM_2.5 exposures and the use of rescue bronchodilator was identified at the 0–24 hours (OR = 1.030; 95% CI = 1.012–1.049; p-value = 0.001) and 0–48 hours (OR = 1.030; 95% CI = 1.013–1.057; p-value = 0.001) prior to lung function measure. Conversely, DBGT exposure at 0 hours (β = 3.257; SE = 0.879; p-value>0.001) and 0–6 hours (β = 2.885; SE = 0.903; p-value = 0.001) hours before a reading were associated with FEV₁. No significant interactions between DBGT and PM_2.5 were observed for rescue bronchodilator use or FEV₁.

Conclusions

Short-term increases in PM_2.5 were associated with increased rescue bronchodilator use, while DBGT was associated with higher lung function (i.e. FEV₁). Further studies are needed to continue to elucidate the mechanisms of acute exposure to PM_2.5 and DBGT on lung function in asthmatics.

Designing Equitable, Transparent Community-Engaged Disaster Research

Disaster research faces significant infrastructure challenges: regional and federal coordination, access to resources, and community collaboration. Disasters can lead to chemical exposures that potentially impact human health and cause concern in affected communities. Community-engaged research, which incorporates local knowledge and voices, is well-suited for work with communities that experience impacts of environmental exposures following disasters. We present three examples of community-engaged disaster research (CEnDR) following oil spills, hurricanes, and wildfires, and their impact on long-term social, physical, and technical community infrastructure. We highlight the following CEnDR structures: researcher/community networks; convenient research tools; adaptable data collection modalities for equitable access; and return of data.

Computational Analysis of Binding Interactions between the Ryanodine Receptor Type 2 and Calmodulin

Mutations in the cardiac ryanodine receptor type 2 (RyR2) have been linked to a variety of cardiac arrhythmias, such as catecholaminergic polymorphic ventricular tachycardia (CPVT). RyR2 is regulated by calmodulin (CaM), and mutations that disrupt their interaction can cause aberrant calcium release, leading to an arrhythmia. It was recently shown that increasing the RyR2-CaM binding affinity could rescue a defective CPVT-related RyR2 channel to near wild-type behavior. However, the interactions that determine the binding affinity at the RyR2-CaM binding interface are not well understood. In this study, we identify the key domains and interactions, including several new interactions, involved in the binding of CaM to RyR2. Also, our comparison between the wild-type and V3599K mutant suggests how the RyR2-CaM binding affinity can be increased via a change in the central and N-terminal lobe binding contacts for CaM. This computational approach provides new insights into the effect of a mutation at the RyR2-CaM binding interface, and it may find utility in drug design for the future treatment of cardiac arrhythmias.

Fact versus fiction: bridging contrasting medicinal cannabis information needs

Regulatory changes now permit the availability and prescribing of medicinal cannabis in Australia. Public awareness and patient interest are high. Using a co-design approach involving cancer patients, carers and oncology and palliative care clinicians, two information resources were developed to provide readily available sources of important information for cancer patients and clinicians who are considering the use of medicinal cannabis. Focus groups and evaluation interviews revealed some areas of dissonance between consumers and clinicians concerning aspects of medicinal cannabis.

Collective Resources and Violent Crime Reconsidered: New Orleans Before and After Hurricane Katrina

Social research has long argued that collective resources and major events like disasters have an important impact on violent crime, but it has been difficult to show their effects because data are scarce. We conducted a large survey in New Orleans after Hurricane Katrina that included questions about collective resources. We aggregated our sample to the census tract level and merged it with data on concentrated disadvantage and violent crime. Our analyses show that bridging social networks are associated with lower levels of violent crime, while bonding social networks are associated with higher levels. Social trust is associated with lower levels of violent crime, but civic engagement has no impact. Concentrated disadvantage is associated with higher levels of violent crime. Finally, our results suggest that disaster recovery increased the importance of collective resources but not concentrated disadvantage on violent crime.

Global demand for cancer surgery and an estimate of the optimal surgical and anaesthesia workforce between 2018 and 2040: a population-based modelling study

BACKGROUND

The growing demand for cancer surgery has placed a global strain on health systems. In-depth analyses of the global demand for cancer surgery and optimal workforce requirements are needed to plan service provision. We estimated the global demand for cancer surgery and the requirements for an optimal surgical and anaesthesia workforce, using benchmarks based on clinical guidelines.

METHODS

Using models of benchmark surgical use based on clinical guidelines, we estimated the proportion of cancer cases with an indication for surgery across 183 countries, stratified by income group. These proportions were multiplied by age-adjusted national estimates of new cancer cases using GLOBOCAN 2018 data and then aggregated to obtain the estimated number of surgical procedures required globally. The numbers of cancer surgical procedures in 44 high-income countries were divided by the actual number of surgeons and anaesthetists in the respective countries to calculate cancer procedures per surgeon and anaesthetist ratios. Using the median (IQR) of these ratios as benchmarks, we developed a three-tiered optimal surgical and anaesthesia workforce matrix, and the predictions were extrapolated up to 2040.

FINDINGS

Our model estimates that the number of cancer cases globally with an indication for surgery will increase by 5 million procedures (52%) between 2018 (9 065 000) and 2040 (13 821 000). The greatest relative increase in surgical demand will occur in 34 low-income countries, where we also observed the largest gaps in workforce requirements. To match the median benchmark for high-income countries, the surgical workforce in these countries would need to increase by almost four times and the anaesthesia workforce by nearly 5·5 times. The greatest increase in optimal workforce requirements from 2018 to 2040 will occur in low-income countries (from 28 000 surgeons to 58 000 surgeons; 107% increase), followed by lower-middle-income countries (from 166 000 surgeons to 277 000 surgeons; 67% increase).

INTERPRETATION

The global demand for cancer surgery and the optimal workforce are predicted to increase over the next two decades and disproportionately affect low-income countries. These estimates provide an appropriate framework for planning the provision of surgical services for cancer worldwide.

FUNDING

University of New South Wales Scientia Scholarship and UK Research and Innovation Global Challenges Research Fund.

Evidence-based benchmarks for use of cancer surgery in high-income countries: a population-based analysis

BACKGROUND

Estimating a population-level benchmark rate for use of surgery in the management of cancer helps to identify treatment gaps, estimate the survival impact of such gaps, and benchmark the workforce and other resources, including budgets, required to meet service needs. A population-based benchmark for use of surgery in high-income settings to inform policy makers and service provision has not been developed but was recommended by the Lancet Oncology Commission on Global Cancer Surgery. We aimed to develop and validate a cancer surgery benchmarking model.

METHODS

We examined the latest clinical guidelines from high-income countries (Australia, the UK, the EU, the USA, and Canada) and mapped surgical treatment pathways for 30 malignant cancer sites (19 individual sites and 11 grouped as other cancers) that were notifiable in Australia in 2014, broadly reflecting contemporary high-income models of care. The optimal use of surgery was considered as an indication for surgery where surgery is the treatment of choice for a given clinical scenario. Population-based epidemiological data, such as cancer stage, tumour characteristics, and fitness for surgery, were derived from Australia and other similar high-income settings for 2017. The probabilities across the clinical pathways of each cancer were multiplied and added together to estimate the population-level benchmark rates of cancer surgery, and further validated with the comparisons of observed rates of cancer surgery in the South Western Sydney Local Health District in 2006-12. Univariable and multivariable sensitivity analyses were done to explore uncertainty around model inputs, with mean (95% CI) benchmark surgery rates estimated on the basis of 10 000 Monte Carlo simulations.

FINDINGS

Surgical treatment was indicated in 58% (95% CI 57-59) of newly diagnosed patients with cancer in Australia in 2014 at least once during the course of their treatment, but varied by site from 23% (17-27) for prostate cancer to 99% (96-99) for testicular cancer. Observed cancer surgery rates in South Western Sydney were comparable to the benchmarks for most cancers, but were higher for some cancers, such as prostate (absolute increase of 29%) and lower for others, such as lung (-14%).

INTERPRETATION

The model provides a new template for high-income and emerging economies to rationally plan and assess their cancer surgery provision. There are differences in modelled versus observed surgery rates for some cancers, requiring more in-depth analysis of the observed differences.

FUNDING

University of New South Wales Scientia Scholarship, UK Research and Innovation-Global Challenges Research Fund.

Factors affecting radiotherapy utilisation in geriatric oncology patients in NSW, Australia

Background and Purpose

Large non-age-specific radiotherapy utilisation rate (RTU) studies have demonstrated that actual RTU is below the optimal recommended utilisation rate for both curative and palliative intent radiotherapy indications. The optimal utilisation rate for the geriatric oncology cohort of patients has not yet been determined. The purpose of this research was to examine the actual RTU for patients treated in New South Wales (NSW), Australia as a function of increasing age, and the relationship between RTU and tumour site, travelling distance and socio-economic status.

Materials & Methods

NSW Central Cancer Registry data (2009-2011) were linked to the NSW Radiotherapy Dataset (2009-2012). RTU was calculated for patients aged <80 years and ≥80 years. RTU was defined as the proportion of patients receiving at least a single course of radiotherapy within 12 months of a cancer diagnosis.

Results

110,645 patients were diagnosed with cancer, of whom 27,721 received at least one course of radiotherapy. The overall RTU was 25%. RTU for patients aged <80 years was 28% compared to 14% for patients aged 80+ years (p < 0.001). On both univariate and multivariate analysis, increasing age, residential address in disadvantaged socioeconomic areas and increasing distance to the nearest radiotherapy department were associated with a reduction in RTU.

Conclusion

Geriatric oncology patients are less likely to receive radiotherapy than their younger counterparts. Some of the reduction in RTU may be justifiable on the basis of limited life expectancy and co-morbidity. Further research is required to determine the co-morbidity adjusted optimal RTU in older patients.

Phototrophic Co-cultures From Extreme Environments: Community Structure and Potential Value for Fundamental and Applied Research

Cyanobacteria are found in most illuminated environments and are key players in global carbon and nitrogen cycling. Although significant efforts have been made to advance our understanding of this important phylum, still little is known about how members of the cyanobacteria affect and respond to changes in complex biological systems. This lack of knowledge is in part due to our dependence on pure cultures when determining the metabolism and function of a microorganism. We took advantage of the Culture Collection of Microorganisms from Extreme Environments (CCMEE), a collection of more than 1,000 publicly available photosynthetic co-cultures maintained at the Pacific Northwest National Laboratory, and assessed via 16S rRNA amplicon sequencing if samples readily available from public culture collection could be used in the future to generate new insights into the role of microbial communities in global and local carbon and nitrogen cycling. Results from this work support the existing notion that culture depositories in general hold the potential to advance fundamental and applied research. Although it remains to be seen if co-cultures can be used at large scale to infer roles of individual organisms, samples that are publicly available from existing co-cultures depositories, such as the CCMEE, might be an economical starting point for such studies. Access to archived biological samples, without the need for costly field work, might in some circumstances be one of the few remaining ways to advance the field and to generate new insights into the biology of ecosystems that are not easily accessible. The current COVID-19 pandemic, which makes sampling expeditions almost impossible without putting the health of the participating scientists on the line, is a very timely example.

Variation in the use of radiotherapy fractionation for breast cancer: Survival outcome and cost implications

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We evaluated the use of hypofractionation in breast radiotherapy in an Australian population-based cohort.

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Hypofractionation appears underused for breast radiotherapy in Australia over time.

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Variation in practice were observed by patient, tumour, sociodemographic and geographical factors.

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This study highlights that evidence-based practice will translate to reduced health care treatment costs.

Background and purpose

Substantial variation in the adoption of hypofractionation for breast radiation therapy has been observed, despite the availability of consensus guidelines. This study aimed to investigate the variation in radiation therapy fractionation in breast cancer patients in New South Wales (NSW), Australia, and to estimate survival outcome and cost implications.

Materials and methods

This is a population-based cohort of patients who received radiation therapy for breast cancer (2009–2013), as captured in the NSW Central Cancer Registry. A logistic regression model was used to identify factors associated with fractionation type. Survival outcome was estimated using multivariable Cox proportional hazards model. Cost per treatment and potential cost saving associated with evidence-based fractionation was estimated.

Results

A total of 10,482 patients were available for analysis, divided into 3 cohorts (breast alone: N = 7000; breast + nodes: N = 1119; all chestwall: N = 2363). In multivariable analysis, increasing age, laterality (right), year of treatment (2013), early stage, lower socioeconomic status, and regional area of residence were independent predictors of hypofractionation for breast alone radiation therapy. For the breast + nodes and chest wall cohorts, common factors that predicted the use of hypofractionation were increasing age. In multivariable survival analysis, there was no difference between the fractionation regimens at 5 years. Estimated radiation therapy cost of this cohort approximated $52.1 million, compared with $38.5 million had these patients been treated with evidence-based fractionation. This demonstrated a potential saving of $13.6 million.

Conclusion

Hypofractionation appears underused for breast radiation therapy in NSW over time. This study highlights that evidence-based practice will translate to reduced health care treatment costs.

Red puffy hand syndrome mistaken for inflammatory arthritis

Red puffy hand syndrome is an uncommon clinical manifestation of intravenous drug abuse, which presents with bilateral, painless and non-pitting erythema and edema of the dorsal hands. The pathophysiology is believed to primarily be the result of lymphatic blockage from either direct toxicity of the injected drug, drainage of impurities, or infection complications. A woman in her 40's with remote intravenous drug use presented with over a decade of fixed, painless erythema and swelling of bilateral dorsal hands. Owing to an elevated rheumatoid factor, which would later be attributed to patient's untreated hepatitis C, these findings were mistaken for rheumatoid arthritis and unnecessarily treated with methotrexate and prednisone. Upon proper recognition of her underlying Red puffy hand syndrome, systemic medications were discontinued and appropriate care was initiated with lymphedema decongestion and occupational therapy. Red puffy hand syndrome, albeit rare, is an important manifestation of intravenous drug abuse; its recognition will spare patients from unnecessary systemic treatments.

Evaluating Residential Segregation's Relation to the Clustering of Poor Health across American Cities

Residential segregation by race/ethnicity is widely recognized as a leading source of health disparities. Not clear from past research, however, is the overall health burden cities face due to clustering brought about by segregation. This study builds on previous research by directly measuring how spatially unequal health outcomes are within segregated cities. Utilizing Census-tract data from the Center for Disease Control and Prevention's 500 Cities project, we examine how different dimensions of spatial segregation are associated with the clustering of poor self-rated health in cities. We make novel usage of the Global Moran's I statistic to measure the spatial clustering of poor health within cities. We find spatial segregation is associated with poor health clustering, however the race/ethnicity and dimension of segregation matter. Our study contributes to existing research on segregation and health by unpacking the localized associations of residential segregation with poor health clustering in U.S. cities.

Factors Associated With Radiotherapy Utilisation In New South Wales, Australia: Results From The 45 and Up Study

AIMS

Actual radiotherapy utilisation rates tend to be lower than the estimated optimal rates. Little is known about the factors contributing to this difference. Our aim was to identify factors associated with radiotherapy receipt for a cohort of cancer patients in New South Wales (NSW), Australia.

MATERIALS AND METHODS

In total, 267 153 participants in the NSW 45 and Up Study completed a questionnaire during 2006-2009 providing detailed health and socio-demographic information and consented to record linkage with administrative health datasets. Single primary cancers diagnosed after study enrolment were identified through linkage with the NSW Cancer Registry to December 2013. Radiotherapy receipt was determined from claims to the Medicare Benefits Schedule and/or records in the NSW Admitted Patient Data Collection (2006 to June 2016). Competing risks regression was used to examine associations between health and socio-demographic characteristics and radiotherapy treatment.

RESULTS

Of 17 873 patients with an incident cancer, 5414 (30.3%) received radiotherapy during follow-up (median 5.3 years). Patients less likely to receive radiotherapy were aged <60 or 80+ years, female, had a Charlson co-morbidity index of 1+, needed help with daily tasks or lived ≥100 km from the nearest radiotherapy centre.

CONCLUSION

Distinct subgroups of patients are less likely to receive radiotherapy. Advocacy and/or policy changes are needed to improve access.

Radiotherapy underutilisation and its impact on local control and survival in New South Wales, Australia

BACKGROUND AND PURPOSE

This study aimed to identify the actual radiotherapy utilisation rate (A-RUR) in New South Wales (NSW) Australia for 2009-2011 and compare that to the published evidence-based optimal radiotherapy utilisation rate (O-RUR) and to previously reported A-RUR in NSW in 2004-2006. It also aimed to estimate the effect of underutilisation on 5-year local control (LC) and overall survival (OS) and identify factors that predict for underutilisation.

MATERIALS AND METHODS

All cases of registered cancer diagnosed in NSW between 2009 and 2011 were identified from the NSW Central Cancer Registry and linked with data from all radiotherapy departments. The A-RUR was calculated and compared with O-RURs for all cancers. The difference for each indication was used to estimate 5-year OS and LC shortfall. Univariate and multivariate analyses were performed to identify factors that correlated with reduced radiotherapy utilisation.

RESULTS

110,645 cancer cases were identified. 25% received radiotherapy within one year of diagnosis compared to an estimated optimal rate of 45%. This has marginally improved from previously reported rate of 22% in NSW in 2004-2006. We estimated that 5-year OS and LC were compromised in 1162 and 5062 patients respectively. Factors that predicted for underuse of radiotherapy were older age, male gender, lower socioeconomic status, increasing distance to nearest radiotherapy centre and localised disease.

CONCLUSION

The identified deficit in radiotherapy use has a significant negative impact on patient outcomes. Strategies to overcome such shortfalls need to be developed to improve radiotherapy use and patient outcomes.

P6555A self-adaptive approach to antitachycardia pacing - a head to head comparison using advanced computational modeling

Background

Antitachycardia pacing (ATP) for monomorphic VT (MVT) reduces painful defibrillation shocks. Most ICD-treated ventricular arrhythmias are MVT, suggesting an opportunity for improved ATP to decrease shocks. We report on a new algorithm (Yee, Circ AE 2017) that uses electrophysiologic (EP) first-principles to design ATP sequences in real-time. Heart-rate history is used to design the first ATP sequence, and failed ATP post-pacing interval is used to design later sequences.

Purpose

The purpose of this modeling study was to understand how this new ATP algorithm would perform in a head-to-head comparison with traditional burst ATP. Modeling allows direct comparison of the two algorithms in identical, realistic, patient-derived cardiac arrythmias.

Methods

Patient-specific late gadolinium enhanced MRI and EP data were used to build an adjudicated cohort of realistic numerical heart models with varied EP, infarct, border zone. Publicly available EP modeling software CARPentry was used to calculate sustained reentrant VT initiated with the programmed electrical stimulation used to induce VT clinically. The VTs were physician-adjudicated to validate models. Burst ATP was 3 sequences of 8 pulses at 88% of VT cycle length, each decremented by 10ms. The new ATP was limited to 3 automatically designed sequences.

Results

Three hundred unique VT scenarios were generated from 6 human hearts with multiple VT circuits, 5 electrophysiologic states, and 10 pacing locations. Burst ATP terminated 168/300 VTs (56%) and accelerated 2.7%. The new ATP terminated 234/300 VTs (78%) with the same acceleration. The two dominant ATP failure mechanisms were identified as 1) insufficient prematurity to close the excitable gap, and 2) failure to reach the critical isthmus of the VT circuit. For these mechanisms, the new ATP algorithm reduce failures from 64 to 28 (44% reduction) without increasing acceleration.

Conclusion

The new automated ATP algorithm successfully adapted ATP sequences for VT episodes that burst ATP failed to terminate. The new ATP was successful even with complex scar geometries and electrophysiology heterogeneity as seen in the real world.

Cancer control in the Pacific: big challenges facing small island states

This Series paper describes the current state of cancer control in Pacific island countries and territories (PICTs). PICTs are diverse but face common challenges of having small, geographically dispersed, isolated populations, with restricted resources, fragile ecological and economic systems, and overburdened health services. PICTs face a triple burden of infection-related cancers, rapid transition to lifestyle-related diseases, and ageing populations; additionally, PICTs are increasingly having to respond to natural disasters associated with climate change. In the Pacific region, cancer surveillance systems are generally weaker than those in high-income countries, and patients often present at advanced cancer stage. Many PICTs are unable to provide comprehensive cancer services, with some patients receiving cancer care in other countries where resources allow. Many PICTs do not have, or have poorly developed, cancer screening, pathology, oncology, surgical, and palliative care services, although some examples of innovative cancer planning, prevention, and treatment approaches have been developed in the region. To improve cancer outcomes, we recommend prioritising regional collaborative approaches, enhancing cervical cancer prevention, improving cancer surveillance and palliative care services, and developing targeted treatment capacity in the region.

Cancer control in the Caribbean island countries and territories: some progress but the journey continues

Cancer causes a fifth of deaths in the Caribbean region and its incidence is increasing. Incidence and mortality patterns of cancer in the Caribbean reflect globally widespread epidemiological transitions, and show cancer profiles that are unique to the region. Providing comprehensive and locally responsive cancer care is particularly challenging in the Caribbean because of the geographical spread of the islands, the frequently under-resourced health-care systems, and the absence of a cohesive approach to cancer control. In many Caribbean countries and territories, cancer surveillance systems are poorly developed, advanced disease presentations are commonplace, and access to cancer screening, diagnostics, and treatment is often suboptimal, with many patients with cancer seeking treatment abroad. Capacity building across the cancer-control continuum in the region is urgently needed and can be accomplished through collaborative efforts and increased investment in health care and cancer control.

Development of an environmental health tool linking chemical exposures, physical location and lung function

BACKGROUND

A challenge in environmental health research is collecting robust data sets to facilitate comparisons between personal chemical exposures, the environment and health outcomes. To address this challenge, the Exposure, Location and lung Function (ELF) tool was designed in collaboration with communities that share environmental health concerns. These concerns centered on respiratory health and ambient air quality. The ELF collects exposure to polycyclic aromatic hydrocarbons (PAHs), given their association with diminished lung function. Here, we describe the ELF as a novel environmental health assessment tool.

METHODS

The ELF tool collects chemical exposure for 62 PAHs using passive sampling silicone wristbands, geospatial location data and respiratory lung function measures using a paired hand-held spirometer. The ELF was tested by 10 individuals with mild to moderate asthma for 7 days. Participants wore a wristband each day to collect PAH exposure, carried a cell phone, and performed spirometry daily to collect respiratory health measures. Location data was gathered using the geospatial positioning system technology in an Android cell-phone.

RESULTS

We detected and quantified 31 PAHs across the study population. PAH exposure data showed spatial and temporal sensitivity within and between participants. Location data was used with existing datasets such as the Toxics Release Inventory and the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System. Respiratory health outcomes were validated using criteria from the American Thoracic Society with 94% of participant data meeting standards. Finally, the ELF was used with a high degree of compliance (> 90%) by community members.

CONCLUSIONS

The ELF is a novel environmental health assessment tool that allows for personal data collection spanning chemical exposures, location and lung function measures as well as self-reported information.

Correlation of ultra-high field MRI with histopathology for evaluation of rectal cancer heterogeneity

Current clinical MRI techniques in rectal cancer have limited ability to examine cancer stroma. The differentiation of tumour from desmoplasia or fibrous tissue remains a challenge. Standard MRI cannot differentiate stage T1 from T2 (invasion of muscularis propria) tumours. Diffusion tensor imaging (DTI) can probe tissue structure and organisation (anisotropy). The purpose of this study was to examine DTI-MRI derived imaging markers of rectal cancer stromal heterogeneity and tumour extent ex vivo. DTI-MRI at ultra-high magnetic field (11.7 tesla) was used to examine the stromal microstructure of malignant and normal rectal tissue ex vivo, and the findings were correlated with histopathology. Images obtained from DTI-MRI (A0, apparent diffusion coefficient and fractional anisotropy (FA)) were used to probe rectal cancer stromal heterogeneity. FA provided the best discrimination between cancer and desmoplasia, fibrous tissue and muscularis propria. Cancer had relatively isotropic diffusion (mean FA 0.14), whereas desmoplasia (FA 0.31) and fibrous tissue (FA 0.34) had anisotropic diffusion with significantly higher FA than cancer (p < 0.001). Tumour was distinguished from muscularis propria (FA 0.61) which was highly anisotropic with higher FA than cancer (p < 0.001). This study showed that DTI-MRI can assist in more accurately defining tumour extent in rectal cancer.

Scale-up of radiotherapy for cervical cancer in the era of human papillomavirus vaccination in low-income and middle-income countries: a model-based analysis of need and economic impact

BACKGROUND

Radiotherapy is standard of care for cervical cancer, but major global gaps in access exist, particularly in low-income and middle-income countries. We modelled the health and economic benefits of a 20-year radiotherapy scale-up to estimate the long-term demand for treatment in the context of human papillomavirus (HPV) vaccination.

METHODS

We applied the Global Task Force on Radiotherapy for Cancer Control investment framework to model the health and economic benefits of scaling up external-beam radiotherapy and brachytherapy for cervical cancer in upper-middle-income, lower-middle-income, and low-income countries between 2015 and 2035. We estimated the unique costs of external-beam radiotherapy and brachytherapy and included a specific valuation of women's caregiving contributions. Model outcomes life-years gained and the human capital and full income net present value of investment. We estimated the effects of stage at diagnosis, radiotherapy delivery system, and simultaneous HPV vaccination (75% coverage) up to a time horizon set at 2072.

FINDINGS

For the period from 2015 to 2035, we estimated that 9·4 million women in low-income and middle-income countries required treatment with external-beam radiotherapy, of which 7·0 million also required treatment with brachytherapy. Incremental scale-up of radiotherapy in these countries from 2015 to meet optimal radiotherapy demand by 2035 yielded 11·4 million life-years gained, $59·3 billion in human capital net present value (-$1·5 billion in low-income, $19·9 billion in lower-middle-income, and $40·9 billion in upper-middle-income countries), and $151·5 billion in full income net present value ($1·5 billion in low-income countries, $53·6 billion in lower-middle-income countries, and $96·4 billion in upper-middle-income countries). Benefits increased with advanced stage of cervical cancer and more efficient scale up of radiotherapy. Bivalent HPV vaccination of 12-year-old girls resulted in a 3·9% reduction in incident cases from 2015-2035. By 2072, when the first vaccinated cohort of girls reaches 70 years of age, vaccination yielded a 22·9% reduction in cervical cancer incidence, with 38·4 million requiring external-beam radiotherapy and 28·8 million requiring brachytherapy.

INTERPRETATION

Effective cervical cancer control requires a comprehensive strategy. Even with HPV vaccination, radiotherapy treatment scale-up remains essential and produces large health benefits and a strong return on investment to countries at different levels of development.

FUNDING

None.

Estimating the cost of radiotherapy for 5-year local control and overall survival benefit

BACKGROUND AND PURPOSE

Escalating health care costs have led to greater efforts directed at measuring the cost and benefits of medical treatments. The aim of this study was to estimate the costs of 5-year local control and overall survival benefits of radiotherapy for the cancer population in Australia.

MATERIALS AND METHODS

The local control and overall survival benefits of radiotherapy at 5-years and optimal number of fractions per course have been estimated for 26 tumour sites for which radiotherapy is indicated. For this study, a hybrid approach that merges features from activity based costing (ABC) and relative value units costing (RVU) were used to provide cost estimates. ABC methodology was used to allocate costs to all radiotherapy activities associated with each patient's treatment course, while the RVUs represent the cost of each radiotherapy activity relative to the average cost of all activities and were used to achieve a weighted cost allocation. A patient's journey for the financial year was constructed by consolidating all the radiotherapy activities and their associated costs, and the average cost per activity (fraction) was determined. The cost of radiotherapy per 5-year overall survival and local control was then estimated.

RESULTS

The estimated population 5-year local control and overall survival benefits of radiotherapy for all cancer were 23% and 6%, respectively. The optimal number of fractions per treatment course if guidelines were followed was 19.4 fractions. The average cost per fraction for all cancer was AU$276. The estimated cost of radiotherapy was AU$23,585 per 5-year local control and AU$86,480 per 5-year overall survival (equivalent to 5 life years) for all cancer.

CONCLUSION

The cost of AU$86,480 per 5-year overall survival would translate to AU$17,296 1-year overall survival. Therefore, the cost of radiotherapy is inexpensive if delivered optimally. Policy implications from this study include knowledge about cost to deliver radiotherapy to allow one to quantify the expected benefit at a population level.

Discovery of common chemical exposures across three continents using silicone wristbands

To assess differences and trends in personal chemical exposure, volunteers from 14 communities in Africa (Senegal, South Africa), North America (United States (U.S.)) and South America (Peru) wore 262 silicone wristbands. We analysed wristband extracts for 1530 unique chemicals, resulting in 400 860 chemical data points. The number of chemical detections ranged from 4 to 43 per wristband, with 191 different chemicals detected, and 1339 chemicals were not detected in any wristband. No two wristbands had identical chemical detections. We detected 13 potential endocrine disrupting chemicals in over 50% of all wristbands and found 36 chemicals in common between chemicals detected in three geographical wristband groups (Africa, North America and South America). U.S. children (less than or equal to 11 years) had the highest percentage of flame retardant detections compared with all other participants. Wristbands worn in Texas post-Hurricane Harvey had the highest mean number of chemical detections (28) compared with other study locations (10-25). Consumer product-related chemicals and phthalates were a high percentage of chemical detections across all study locations (36-53% and 18-42%, respectively). Chemical exposures varied among individuals; however, many individuals were exposed to similar chemical mixtures. Our exploratory investigation uncovered personal chemical exposure trends that can help prioritize certain mixtures and chemical classes for future studies.