Biofilm of petroleum-based and bio-based microplastics in seawater in response to Zn(II): Biofilm formation, community structure, and microbial function

Microplastic biofilms are novel vectors for the transport and spread of pathogenic and drug-resistant bacteria. With the increasing use of bio-based plastics, there is an urgent need to investigate the microbial colonization characteristics of these materials in seawater, particularly in comparison with conventional petroleum-based plastics. Furthermore, the effect of co-occurring contaminants, such as heavy metals, on the formation of microplastic biofilms and bacterial communities remains unclear. In this study, we compared the biofilm bacterial community structure of petroleum-based polyethylene (PE) and bio-based polylactic acid (PLA) in seawater under the influence of zinc ions (Zn2+). Our findings indicate that the biofilm on PLA microplastics in the late stage was impeded by the formation of a mildly acidic microenvironment resulting from the hydrolysis of the ester group on PLA. The PE surface had higher bacterial abundance and diversity, with a more intricate symbiotic pattern. The bacterial structures on the two types of microplastics were different; PE was more conducive to the colonization of anaerobic bacteria, whereas PLA was more favorable for the colonization of aerobic and acid-tolerant species. Furthermore, Zn increased the proportion of the dominant genera that could utilize microplastics as a carbon source, such as Alcanivorax and Nitratireductor. PLA had a greater propensity to harbor and disseminate pathogenic and drug-resistant bacteria, and Zn promoted the enrichment and spread of harmful bacteria such as, Pseudomonas and Clostridioides. Therefore, further research is essential to fully understand the potential environmental effects of bio-based microplastics and the role of heavy metals in the dynamics of bacterial colonization.

Physician and Artificial Intelligence Chatbot Responses to Cancer Questions From Social Media

Importance

Artificial intelligence (AI) chatbots pose the opportunity to draft template responses to patient questions. However, the ability of chatbots to generate responses based on domain-specific knowledge of cancer remains to be tested.

Objective

To evaluate the competency of AI chatbots (GPT-3.5 [chatbot 1], GPT-4 [chatbot 2], and Claude AI [chatbot 3]) to generate high-quality, empathetic, and readable responses to patient questions about cancer.

Design, Setting, and Participants

This equivalence study compared the AI chatbot responses and responses by 6 verified oncologists to 200 patient questions about cancer from a public online forum. Data were collected on May 31, 2023.

Exposures

Random sample of 200 patient questions related to cancer from a public online forum (Reddit r/AskDocs) spanning from January 1, 2018, to May 31, 2023, was posed to 3 AI chatbots.

Main Outcomes and Measures

The primary outcomes were pilot ratings of the quality, empathy, and readability on a Likert scale from 1 (very poor) to 5 (very good). Two teams of attending oncology specialists evaluated each response based on pilot measures of quality, empathy, and readability in triplicate. The secondary outcome was readability assessed using Flesch-Kincaid Grade Level.

Results

Responses to 200 questions generated by chatbot 3, the best-performing AI chatbot, were rated consistently higher in overall measures of quality (mean, 3.56 [95% CI, 3.48-3.63] vs 3.00 [95% CI, 2.91-3.09]; P < .001), empathy (mean, 3.62 [95% CI, 3.53-3.70] vs 2.43 [95% CI, 2.32-2.53]; P < .001), and readability (mean, 3.79 [95% CI, 3.72-3.87] vs 3.07 [95% CI, 3.00-3.15]; P < .001) compared with physician responses. The mean Flesch-Kincaid Grade Level of physician responses (mean, 10.11 [95% CI, 9.21-11.03]) was not significantly different from chatbot 3 responses (mean, 10.31 [95% CI, 9.89-10.72]; P > .99) but was lower than those from chatbot 1 (mean, 12.33 [95% CI, 11.84-12.83]; P < .001) and chatbot 2 (mean, 11.32 [95% CI, 11.05-11.79]; P = .01).

Conclusions and Relevance

The findings of this study suggest that chatbots can generate quality, empathetic, and readable responses to patient questions comparable to physician responses sourced from an online forum. Further research is required to assess the scope, process integration, and patient and physician outcomes of chatbot-facilitated interactions.

Reliability and Variability of Ki-67 Digital Image Analysis Methods for Clinical Diagnostics in Breast Cancer

Ki-67 is a nuclear protein associated with proliferation, and a strong potential biomarker in breast cancer, but is not routinely measured in current clinical management owing to a lack of standardization. Digital image analysis (DIA) is a promising technology that could allow high-throughput analysis and standardization. There is a dearth of data on the clinical reliability as well as intra- and interalgorithmic variability of different DIA methods. In this study, we scored and compared a set of breast cancer cases in which manually counted Ki-67 has already been demonstrated to have prognostic value (n = 278) to 5 DIA methods, namely Aperio ePathology (Lieca Biosystems), Definiens Tissue Studio (Definiens AG), Qupath, an unsupervised immunohistochemical color histogram algorithm, and a deep-learning pipeline piNET. The piNET system achieved high agreement (interclass correlation coefficient: 0.850) and correlation (R = 0.85) with the reference score. The Qupath algorithm exhibited a high degree of reproducibility among all rater instances (interclass correlation coefficient: 0.889). Although piNET performed well against absolute manual counts, none of the tested DIA methods classified common Ki-67 cutoffs with high agreement or reached the clinically relevant Cohen's κ of at least 0.8. The highest agreement achieved was a Cohen's κ statistic of 0.73 for cutoffs 20% and 25% by the piNET system. The main contributors to interalgorithmic variation and poor cutoff characterization included heterogeneous tumor biology, varying algorithm implementation, and setting assignments. It appears that image segmentation is the primary explanation for semiautomated intra-algorithmic variation, which involves significant manual intervention to correct. Automated pipelines, such as piNET, may be crucial in developing robust and reproducible unbiased DIA approaches to accurately quantify Ki-67 for clinical diagnosis in the future.

Ent-eudesmane sesquiterpenoids with anti-neuroinflammatory activity from the marine-derived fungus Eutypella sp. F0219

In this study, twenty-three ent-eudesmane sesquiterpenoids (1-23) including fifteen previously undescribed ones, named eutypelides A-O (1-15) were isolated from the marine-derived fungus Eutypella sp. F0219. Their planar structures and relative configurations were established by HR-ESIMS and extensive 1D and 2D NMR investigations. The absolute configurations of the previously undescribed compounds were determined by single-crystal X-ray diffraction analyses, modified Mosher's method, and ECD calculations. Structurally, eutypelide A (1) is a rare 1,10-seco-ent-eudesmane, whereas 2-15 are typically ent-eudesmanes with 6/6/-fused bicyclic carbon nucleus. The anti-neuroinflammatory activity of all isolated compounds (1-23) was accessed based on their ability to NO production in LPS-stimulated BV2 microglia cells. Compound 16 emerged as the most potent inhibitor. Further mechanistic investigation revealed that compound 16 modulated the inflammatory response by decreasing the protein levels of iNOS and increasing ARG 1 levels, thereby altering the iNOS/ARG 1 ratio and inhibiting macrophage polarization. qRT-PCR analysis showed that compound 16 reversed the LPS-induced upregulation of pro-inflammatory cytokines, including iNOS, TNF-α, IL-6, and IL-1β, at both the transcriptional and translational levels. These effects were linked to the inhibition of the NF-κB pathway, a key regulator of inflammation. Our findings suggest that compound 16 may be a potential structure basis for developing neuroinflammation-related disease therapeutic agents.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

CyanoStrainChip: A Novel DNA Microarray Tool for High-Throughput Detection of Environmental Cyanobacteria at the Strain Level

Detecting cyanobacteria in environments is an important concern due to their crucial roles in ecosystems, and they can form blooms with the potential to harm humans and nonhuman entities. However, the most widely used methods for high-throughput detection of environmental cyanobacteria, such as 16S rRNA sequencing, typically provide above-species-level resolution, thereby disregarding intraspecific variation. To address this, we developed a novel DNA microarray tool, termed the CyanoStrainChip, that enables strain-level comprehensive profiling of environmental cyanobacteria. The CyanoStrainChip was designed to target 1277 strains; nearly all major groups of cyanobacteria are included by implementing 43,666 genome-wide, strain-specific probes. It demonstrated strong specificity by in vitro mock community experiments. The high correlation (Pearson's R > 0.97) between probe fluorescence intensities and the corresponding DNA amounts (ranging from 1-100 ng) indicated excellent quantitative capability. Consistent cyanobacterial profiles of field samples were observed by both the CyanoStrainChip and next-generation sequencing methods. Furthermore, CyanoStrainChip analysis of surface water samples in Lake Chaohu uncovered a high intraspecific variation of abundance change within the genus Microcystis between different severity levels of cyanobacterial blooms, highlighting two toxic Microcystis strains that are of critical concern for Lake Chaohu harmful blooms suppression. Overall, these results suggest a potential for CyanoStrainChip as a valuable tool for cyanobacterial ecological research and harmful bloom monitoring to supplement existing techniques.

Progress in site-specific cancer mortality in Canada over the last 70 years

In Canada, the absolute number of cancer deaths has been steadily increasing, however, age-standardized cancer mortality rates peaked decades ago for most cancers. The objective of this study was to estimate the reduction in deaths for each cancer type under the scenario where peak mortality rates had remained stable in Canada. Data for this study were obtained the Global Cancer Observatory and Statistics Canada. We estimated age-standardized mortality rates (ASMR, per 100,000) from 1950 to 2022, standardized to the 2011 Canadian standard population. We identified peak mortality rates and applied the age-specific mortality rates from the peak year to the age-specific Canadian population estimates for subsequent years (up to 2022) to estimate the number of expected deaths. Avoided cancer deaths were the difference between the observed and expected number of cancer deaths. There have been major reductions in deaths among cancers related to tobacco consumption and other modifiable lifestyle habits (417,561 stomach; 218,244 colorectal; 186,553 lung; 66,281 cervix; 32,732 head and neck; 27,713 bladder; 22,464 leukemia; 20,428 pancreas; 8863 kidney; 3876 esophagus; 290 liver). There have been 201,979 deaths avoided for female-specific cancers (breast, cervix, ovary, uterus). Overall, there has been a 34% reduction in mortality for lung cancer among males and a 9% reduction among females. There has been a significant reduction in cancer mortality in Canada since site-specific cancer mortality rates peaked decades ago for many cancers. This shows the exceptional progress made in cancer control in Canada due to substantial improvements in prevention, screening, and treatment. This study highlights priority areas where more attention and investment are needed to achieve progress.

The effects of obstructive sleep apnea on blood pressure variability and load in patients with hypertension

BACKGROUND

Hypertension frequently coexists with obstructive sleep apnea (OSA), and their interplay substantially impacts the prognosis of affected individuals. Investigating the influence of OSA on blood pressure variability (BPV) and blood pressure load (BPL) in hypertensive patients has become a focal point of clinical research.

METHODS

This cross-sectional study recruited hypertensive patients (n = 265) without discrimination and classified them into four groups based on their apnea-hypopnea index (AHI): control group (n = 40), AHI < 5; mild group (n = 74), 5 ≤ AHI ≤ 15; moderate group (n = 68), 15 < AHI ≤ 30; severe group (n = 83), AHI > 30. All participants underwent comprehensive assessments, including polysomnography (PSG) monitoring, 24-h ambulatory blood pressure (ABP) monitoring, cardiac Doppler ultrasound, and additional examinations when indicated.

RESULTS

BPV and BPL exhibited significant elevations in the moderate and severe OSA groups compared to the control and mild OSA groups (P < 0.05). Moreover, interventricular septum thickness and left ventricular end-diastolic volume (LVEDV) demonstrated higher values in the moderate and severe OSA groups (P < 0.05). Multiple stepwise regression analysis identified noteworthy risk factors for elevated BPV in hypertensive patients with OSA, including AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea.

CONCLUSION

Hypertensive patients with moderate to severe OSA exhibited substantially increased BPV and BPL. Moreover, BPV was correlated with AHI, maximum apnea time, total times of oxygen reduction, and mean time of apnea in hypertensive patients with OSA.

Three new species of Cortinarius section Delibuti (Cortinariaceae, Agaricales) from China

Three new species of CortinariussectionDelibuti, namely C.fibrillososalor, C.pseudosalor, and C.subtropicus are described as new to science based on morphological and phylogenetic evidences. Cortinariuspseudosalor is extremely morphologically similar to C.salor, but it differs from the latter by smaller coarsely verrucose basidiospores. Cortinariusfibrillososalor can be easily differentiated by its fibrillose pileus. The pileus of C.subtropicus becomes brown without lilac tint at maturity comparing with other members of section Delibuti. A combined dataset of ITS and LSU sequences was used for phylogenetic analysis. The phylogenetic reconstruction of section Delibuti revealed that these three new species clustered and formed independent lineages with full support respectively. A key to the three new species and related species of section Delibuti is provided in this work.

Controllable nonreciprocal phonon laser in a hybrid photonic molecule based on directional quantum squeezing

Here, a scheme for a controllable nonreciprocal phonon laser is proposed in a hybrid photonic molecule system consisting of a whispering-gallery mode (WGM) optomechanical resonator and a χ(2)-nonlinear WGM resonator, by directionally quantum squeezing one of two coupled resonator modes. The directional quantum squeezing results in a chiral photon interaction between the resonators and a frequency shift of the squeezed resonator mode with respect to the unsqueezed bare mode. We show that the directional quantum squeezing can modify the effective optomechanical coupling in the optomechanical resonator, and analyze the impacts of driving direction and squeezing extent on the phonon laser action in detail. Our analytical and numerical results indicate that the controllable nonreciprocal phonon laser action can be effectively realized in this system. The proposed scheme uses an all-optical and chip-compatible approach without spinning resonators, which may be more beneficial for integrating and packaging of the system on a chip. Our proposal may provide a new route to realize integratable phonon devices for on-chip nonreciprocal phonon manipulations, which may be used in chiral quantum acoustics, topological phononics, and acoustical information processing.

AI improves accuracy, agreement and efficiency of pathologists for Ki67 assessments in breast cancer

The Ki-67 proliferation index (PI) guides treatment decisions in breast cancer but suffers from poor inter-rater reproducibility. Although AI tools have been designed for Ki-67 assessment, their impact on pathologists' work remains understudied. 90 international pathologists were recruited to assess the Ki-67 PI of ten breast cancer tissue microarrays with and without AI. Accuracy, agreement, and turnaround time with and without AI were compared. Pathologists' perspectives on AI were collected. Using AI led to a significant decrease in PI error (2.1% with AI vs. 5.9% without AI, p < 0.001), better inter-rater agreement (ICC: 0.70 vs. 0.92; Krippendorff's α: 0.63 vs. 0.89; Fleiss' Kappa: 0.40 vs. 0.86), and an 11.9% overall median reduction in turnaround time. Most pathologists (84%) found the AI reliable. For Ki-67 assessments, 76% of respondents believed AI enhances accuracy, 82% said it improves consistency, and 83% trust it will improve efficiency. This study highlights AI's potential to standardize Ki-67 scoring, especially between 5 and 30% PI-a range with low PI agreement. This could pave the way for a universally accepted PI score to guide treatment decisions, emphasizing the promising role of AI integration into pathologist workflows.

High-quality genome resource of Lasiodiplodia pseudotheobromae associated with die-back on Eucalyptus trees

OBJECTIVES

Lasiodiplodia pseudotheobromae is an important fungal pathogen associated with die-back, canker and shoot blight in many plant hosts with a wide geographic distribution. The aim of our study was to provide high-quality genome assemblies and sequence annotation resources of L. pseudotheobromae, to facilitate future studies on the systematics, population genetics and genomics of the fungal pathogen L. pseudotheobromae.

DATA DESCRIPTION

High-quality genomes of five L. pseudotheobromae isolates were sequenced based on Oxford Nanopore technology (ONT) and Illumina HiSeq sequencing platform. The total size of each assembly ranged from 43 Mb to 43.86 Mb and over 11,000 protein-coding genes were predicted from each genome. The proteins of predicted genes were annotated using multiple public databases, among the annotated protein-coding genes, more than 4,300 genes were predicted as potential virulence genes by the Pathogen Host Interactions (PHI) database. Moreover, the genome comparative analysis among L. pseudotheobromae and other closely related species revealed that 7,408 gene clusters were shared among them and 152 gene clusters unique to L. pseudotheobromae. This genome and associated datasets provided here will serve as a useful resource for further analyses of this fungal pathogen species.

Progress in cancer control leads to a substantial number of cancer deaths avoided in Canada

It is currently not known how many more cancer deaths would have occurred among Canadians if cancer mortality rates were unchanged following various modern human interventions. The objective of this study was to estimate the number of cancer deaths that have been avoided in Canada since the age-standardized overall cancer mortality rate peaked in 1988. We applied the age-specific overall cancer mortality rates from 1988 to the Canadian population for all subsequent years to estimate the number of expected deaths. Avoided cancer deaths were estimated as the difference between the observed and expected number of cancer deaths for each year. Since 1988, there have been 372 584 (standardized mortality ratio = 0.77) and 120 045 (standardized mortality ratio = 0.90) avoided cancer deaths in males and females, respectively (492 629 total). Nearly half a million cancer deaths have been avoided in Canada since the overall cancer mortality rate peaked, which demonstrates the exceptional progress made in modern cancer control in Canada.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer

BACKGROUND

Adjuvant radiotherapy is prescribed after breast-conserving surgery to reduce the risk of local recurrence. However, radiotherapy is inconvenient, costly, and associated with both short-term and long-term side effects. Clinicopathologic factors alone are of limited use in the identification of women at low risk for local recurrence in whom radiotherapy can be omitted. Molecularly defined intrinsic subtypes of breast cancer can provide additional prognostic information.

METHODS

We performed a prospective cohort study involving women who were at least 55 years of age, had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, luminal A-subtype breast cancer (defined as estrogen receptor positivity of ≥1%, progesterone receptor positivity of >20%, negative human epidermal growth factor receptor 2, and Ki67 index of ≤13.25%), and had received adjuvant endocrine therapy. Patients who met the clinical eligibility criteria were registered, and Ki67 immunohistochemical analysis was performed centrally. Patients with a Ki67 index of 13.25% or less were enrolled and did not receive radiotherapy. The primary outcome was local recurrence in the ipsilateral breast. In consultation with radiation oncologists and patients with breast cancer, we determined that if the upper boundary of the two-sided 90% confidence interval for the cumulative incidence at 5 years was less than 5%, this would represent an acceptable risk of local recurrence at 5 years.

RESULTS

Of 740 registered patients, 500 eligible patients were enrolled. At 5 years after enrollment, recurrence was reported in 2.3% of the patients (90% confidence interval [CI], 1.3 to 3.8; 95% CI, 1.2 to 4.1), a result that met the prespecified boundary. Breast cancer occurred in the contralateral breast in 1.9% of the patients (90% CI, 1.1 to 3.2), and recurrence of any type was observed in 2.7% (90% CI, 1.6 to 4.1).

CONCLUSIONS

Among women who were at least 55 years of age and had T1N0, grade 1 or 2, luminal A breast cancer that were treated with breast-conserving surgery and endocrine therapy alone, the incidence of local recurrence at 5 years was low with the omission of radiotherapy. (Funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation; LUMINA ClinicalTrials.gov number, NCT01791829.).

An effective QUATRE algorithm based on reorganized mechanism and its application for parameter estimation in improved photovoltaic module

The traditional parameter estimation methods for photovoltaic (PV) module are strictly limited by the reference standards. On the basis of the double diode model (DDM), this paper proposes a modified PV module that is independent of the reference conditions and can be used for the transformation and reconfiguration of PV module. With respect to the issue of the slow convergence precision and the tendency to trap in the local extremum of the QUATRE algorithm, this research incorporates the QUATRE algorithm with recombination mechanism (RQUATRE) to tackle the problem of parameter estimation for the improved PV modules described above. Simulation data show that the RQUATRE wins 29, 29, 21, 17 and 15 times with the FMO, PIO, QUATRE, PSO and GWO algorithms on the CEC2017 test suite. In addition, in a modified PV module for the parameter extraction problem, the final experimental results achieved a value of 2.99 × 10^-3 at RMSE, all better than the accuracy values of the compared algorithms. In the fitting process of IAE, the final values are also all less than 10%, which can satisfy the fitting needs.

Multi-institutional Prognostic Modeling in Head and Neck Cancer: Evaluating Impact and Generalizability of Deep Learning and Radiomics

Artificial intelligence (AI) and machine learning (ML) are becoming critical in developing and deploying personalized medicine and targeted clinical trials. Recent advances in ML have enabled the integration of wider ranges of data including both medical records and imaging (radiomics). However, the development of prognostic models is complex as no modeling strategy is universally superior to others and validation of developed models requires large and diverse datasets to demonstrate that prognostic models developed (regardless of method) from one dataset are applicable to other datasets both internally and externally. Using a retrospective dataset of 2,552 patients from a single institution and a strict evaluation framework that included external validation on three external patient cohorts (873 patients), we crowdsourced the development of ML models to predict overall survival in head and neck cancer (HNC) using electronic medical records (EMR) and pretreatment radiological images. To assess the relative contributions of radiomics in predicting HNC prognosis, we compared 12 different models using imaging and/or EMR data. The model with the highest accuracy used multitask learning on clinical data and tumor volume, achieving high prognostic accuracy for 2-year and lifetime survival prediction, outperforming models relying on clinical data only, engineered radiomics, or complex deep neural network architecture. However, when we attempted to extend the best performing models from this large training dataset to other institutions, we observed significant reductions in the performance of the model in those datasets, highlighting the importance of detailed population-based reporting for AI/ML model utility and stronger validation frameworks. We have developed highly prognostic models for overall survival in HNC using EMRs and pretreatment radiological images based on a large, retrospective dataset of 2,552 patients from our institution.Diverse ML approaches were used by independent investigators. The model with the highest accuracy used multitask learning on clinical data and tumor volume.External validation of the top three performing models on three datasets (873 patients) with significant differences in the distributions of clinical and demographic variables demonstrated significant decreases in model performance.

Significance

ML combined with simple prognostic factors outperformed multiple advanced CT radiomics and deep learning methods. ML models provided diverse solutions for prognosis of patients with HNC but their prognostic value is affected by differences in patient populations and require extensive validation.

[Epidemiological characteristics of norovirus acute gastroenteritis outbreaks and influencing factors in China, 2007-2021]

Objective: To analyze the epidemiological characteristics of norovirus-caused acute gastroenteritis outbreaks in China, identify the factors influencing the scale of outbreaks, and provide scientific evidences for early control of norovirus infection outbreaks. Methods: The descriptive epidemiological analysis approach was applied to analyze the incidence of national norovirus infection outbreaks by using the data from the Public Health Emergency Event Surveillance System in China from January 1, 2007 to December 31, 2021. The unconditional logistic regression model was applied to analyze the risk factors that affected the outbreaks' scale. Results: A total of 1 725 norovirus infection outbreaks were recorded in China from 2007 to 2021, with an upward trend in the number of the reported outbreaks. The southern provinces had their annual outbreak peaks from October to March; the northern provinces had two outbreak peaks from October to December and from March to June annually. The outbreaks occurred mainly in southeastern coastal provinces with a trend of gradual spread to central, northeastern and western provinces. The outbreaks mainly occurred in schools and childcare setting (1 539 cases, 89.22%), followed by enterprises and institutions (67 cases, 3.88%) and community households (55 cases, 3.19%). Human to human transmission was the main infection route (73.16%), and norovirus GⅡ genotype was the predominate pathogen causing the outbreaks (899 cases, 81.58%). The time interval between the onset of the primary case and the outbreak reporting M (Q₁, Q₃) was 3 (2, 6) days and the case number of the outbreak M (Q₁, Q₃) was 38 (28, 62). The timeliness of outbreak reporting was improved in recent years and the scale of the outbreaks showed a decreasing trend over the years, the differences in reporting timeliness and outbreak scale among different settings were significant (P<0.001). The factors that affected outbreaks' scale included the outbreak setting, transmission route, outbreak reporting timeliness and type of living areas (P<0.05). Conclusions: From 2007 to 2021, the number of the norovirus-caused acute gastroenteritis outbreaks increased in China and the more areas were affected. However, the outbreak scale showed a decreasing trend and the outbreak reporting timeliness was improved. It is important to further improve the surveillance sensitivity and reporting timeliness for the effective control of the outbreak scale.

[Epidemiological characteristics of typhoid fever and paratyphoid fever in China, 2004-2020]

Objective: To analyze the incidence trend and epidemiological characteristics of typhoid fever and paratyphoid fever in China from 2004 to 2020, understand the high-incidence population and hotspot areas, and provide evidences to develop more targeted prevention and control measures. Methods: The descriptive epidemiological method and spatial analysis method were applied to analyze the epidemiological characteristics of typhoid fever and paratyphoid fever in China during this period by using the surveillance data collected from the National Notifiable Infectious Disease Reporting System of Chinese Center for Disease Control and Prevention. Results: A total of 202 991 cases of typhoid fever were reported in China from 2004 to 2020. More cases occurred in men than in women (sex ratio: 1.18∶1). Most cases were reported in adults aged 20-59 years (53.60%). The incidence rate of typhoid fever decreased from 2.54/100 000 in 2004 to 0.38/100 000 in 2020. The highest incidence rate was reported in young children aged <3 years after 2011, ranging from 1.13/100 000 to 2.78/100 000, and during this period the proportion of cases in this age group increased from 3.48% to 15.59%. The proportion of the cases in the elderly aged ≥60 years increased from 6.46% in 2004 to 19.34% in 2020. The hotspot areas existed in Yunnan, Guizhou, Guangxi and Sichuan Provinces and expanded to Guangdong, Hunan, Jiangxi, and Fujian Provinces. A total of 86 226 paratyphoid fever cases were reported from 2004 to 2020, the male to female ratio of the cases was 1.21∶1. Most cases were reported in adults aged 20-59 years (59.80%). The incidence rate of paratyphoid fever decreased from 1.26/100 000 in 2004 to 0.12/100 000 in 2020. The highest incidence rate of paratyphoid fever was in young children aged <3 years after 2007, ranging from 0.57/100 000 to 1.19/100 000, and during this period the proportion of the cases in this age group increased from 1.48% to 30.92%. The proportion of the cases in the elderly aged ≥60 years increased from 4.52% in 2004 to 22.28% in 2020. The hotspot areas expanded to the east, including Guangdong, Hunan and Jiangxi Provinces, from Yunnan, Guizhou, Sichuan, and Guangxi Provinces. Conclusions: The results showed a low level of incidence of typhoid fever and paratyphoid fever in China with a trend of decreasing per year. The hotspots were mainly in the of Yunnan, Guizhou, Guangxi and Sichuan Provinces, with an expanding trend to eastern China. It is necessary to strengthen the typhoid fever and paratyphoid fever prevention and control in southwestern China, among young children aged <3 years and the elderly aged ≥60 years.

Use of artificial intelligence for cancer clinical trial enrollment: a systematic review and meta-analysis

BACKGROUND

The aim of this study is to provide a comprehensive understanding of the current landscape of artificial intelligence (AI) for cancer clinical trial enrollment and its predictive accuracy in identifying eligible patients for inclusion in such trials.

METHODS

Databases of PubMed, Embase, and Cochrane CENTRAL were searched until June 2022. Articles were included if they reported on AI actively being used in the clinical trial enrollment process. Narrative synthesis was conducted among all extracted data: accuracy, sensitivity, specificity, positive predictive value, and negative predictive value. For studies where the 2x2 contingency table could be calculated or supplied by authors, a meta-analysis to calculate summary statistics was conducted using the hierarchical summary receiver operating characteristics curve model.

RESULTS

Ten articles reporting on more than 50 000 patients in 19 datasets were included. Accuracy, sensitivity, and specificity exceeded 80% in all but 1 dataset. Positive predictive value exceeded 80% in 5 of 17 datasets. Negative predictive value exceeded 80% in all datasets. Summary sensitivity was 90.5% (95% confidence interval [CI] = 70.9% to 97.4%); summary specificity was 99.3% (95% CI = 81.8% to 99.9%).

CONCLUSIONS

AI demonstrated comparable, if not superior, performance to manual screening for patient enrollment into cancer clinical trials. As well, AI is highly efficient, requiring less time and human resources to screen patients. AI should be further investigated and implemented for patient recruitment into cancer clinical trials. Future research should validate the use of AI for clinical trials enrollment in less resource-rich regions and ensure broad inclusion for generalizability to all sexes, ages, and ethnicities.

Neurotrophin signaling is a central mechanism of salivary dysfunction after irradiation that disrupts myoepithelial cells

The mechanisms that prevent regeneration of irradiated (IR) salivary glands remain elusive. Bulk RNAseq of IR versus non-IR human salivary glands showed that neurotrophin signaling is highly disrupted post-radiation. Neurotrophin receptors (NTRs) were significantly upregulated in myoepithelial cells (MECs) post-IR, and single cell RNAseq revealed that MECs pericytes, and duct cells are the main sources of neurotrophin ligands. Using two ex vivo models, we show that nerve growth factor (NGF) induces expression of MEC genes during development, and upregulation of NTRs in adult MECs is associated with stress-induced plasticity and morphological abnormalities in IR human glands. As MECs are epithelial progenitors after gland damage and are required for proper acinar cell contraction and secretion, we propose that MEC-specific upregulation of NTRs post-IR disrupts MEC differentiation and potentially impedes the ability of the gland to regenerate.

Development and Validation of a Genomic Profile for the Omission of Local Adjuvant Radiation in Breast Cancer

PURPOSE

Adjuvant radiotherapy (RT) is used for women with early-stage invasive breast cancer treated with breast-conserving surgery. However, some women with low risk of recurrence may safely be spared RT. This study aimed to identify these women using a molecular-based approach.

METHODS

We analyzed two randomized trials of women with node-negative invasive breast cancer to ± RT following breast-conserving surgery: SweBCG91-RT (stage I-II, no adjuvant systemic therapy) and Princess Margaret (age 50 years or older, T1-T2, adjuvant tamoxifen). Transcriptome-wide profiling was performed (Affymetrix Human Exon 1.0 ST microarray). Patients with estrogen receptor-positive/human epidermal growth factor receptor 2-negative tumors and with gene expression data were included. The SweBCG91-RT cohort was divided into training (N = 243) and validation (N = 354) cohorts. A 16-gene signature named Profile for the Omission of Local Adjuvant Radiation (POLAR) was trained to predict locoregional recurrence (LRR) using elastic net regression. POLAR was then validated in the SweBCG91-RT validation cohort and the Princess Margaret cohort (N = 132).

RESULTS

Patients categorized as POLAR low-risk without RT had a 10-year LRR of 6% (95% CI, 2 to 16) and 7% (0 to 27) in SweBCG91-RT and Princess Margaret cohorts, respectively. There was no significant benefit from RT in POLAR low-risk patients (hazard ratio [HR], 1.1 [0.39 to 3.4], P = .81, and HR, 1.5 [0.14 to 16], P = .74, respectively). Patients categorized as POLAR high-risk had a significant decreased risk of LRR with RT (HR, 0.43 [0.24 to 0.78], P = .0055, and HR, 0.25 [0.07 to 0.92], P = .038, respectively). An exploratory analysis testing for interaction between RT and POLAR in the combined validation cohort was performed (P = .066).

CONCLUSION

The novel POLAR genomic signature on the basis of LRR biology may identify patients with a low risk of LRR despite not receiving RT, and thus may be candidates for RT omission.

Abstract GS4-03: Validation of Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) in a meta-analysis of three randomized controlled trials of breast conserving surgery +/- radiotherapy

Background: There are currently no commercially available tests to identify early stage breast cancer patients treated with breast conserving surgery (BCS) and systemic therapy at low risk of locoregional recurrence (LRR) for whom postoperative radiotherapy (RT) may be safely omitted. Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) is a 16-gene molecular signature developed to identify invasive breast cancer patients who may be candidates for RT omission after BCS. In this work, we seek to validate POLAR in a meta-analysis of three RCTs of BCS +/- RT: SweBCG91RT, Scottish Conservation Trial (SCT) and Princess Margaret Hospital (PMH).

Methods: A patient-level meta-analysis was performed in 623 node-negative breast cancer patients with ER+/HER2-negative tumors who were enrolled in the three RCTs and for whom primary tumor material was available for analysis. Contributions from each cohort were as follows: SweBCG91RT N=354 (57%), SCT N=137 (22%), and PMH N=132 (21%). Numbers of LRR events in each cohort were as follows: SweBCG91RT N=72 (20%), SCT N=28 (20%), and PMH N=16 (12%). There was a mix of systemic therapy used (no systemic therapy for SweBCG91RT, chemotherapy or adjuvant endocrine therapy, but not both, in SCT, and tamoxifen but no chemotherapy for PMH). Median follow-up time for the patients who did not have LRR was 13.3 years for SweBCG91RT, 21.1 years for SCT, and 8.6 years for PMH. A multivariable Cox proportional hazards model on time to LRR, including the continuous standardized POLAR score, RT, and interaction, stratified by cohort, was used to test the interaction between the continuous POLAR score and RT. Additional Cox models tested the association between treatment arms separately for patients with a low and high POLAR score using a pre-specified cut point. Cumulative incidences were computed, with distant metastasis and death without recurrence considered as competing events.

Results: The test for interaction between RT treatment and POLAR was statistically significant (p = 0.022). Patients with a high POLAR score (N=429 [69%]) had a large benefit from RT (10-year cumulative incidence of LRR: 20% [15%-26%] for those not treated with RT vs 7% [4%-11%] for those treated with RT; hazard ratio for RT vs no RT: 0.37 [0.23-0.60], p &lt; 0.001), whereas there was no evidence of benefit from RT for patients with a low POLAR score (N=194 [31%], 10-year cumulative incidence of LRR: 5% [2%-11%] for those not treated with RT vs 7% [3%-14%] for those treated with RT; hazard ratio for RT vs no RT: 0.92 [0.42-2.02], p = 0.832).

Conclusions: To our knowledge, POLAR is the first genomic classifier that is not only prognostic for LRR but also predictive, showing a significant interaction between RT and the classifier. Patients with a high POLAR score should be recommended radiotherapy while patients with a low score may be candidates for omission of radiotherapy after breast conserving surgery.

Citation Format: Per Karlsson, Anthony Fyles, S. Laura Chang, Bradley Arrick, Frederick Baehner, Per Malmström, Mårten Fernö, Erik Holmberg, Martin Sjöström, Fei-Fei Liu, David A. Cameron, Linda J. Williams, John MS Bartlett, Joanna Dunlop, Jacqueline Caldwell, Joseph F. Loane, Elizabeth Mallon, Tammy Piper, Wilma J. Jack, Ian Kunkler, Felix Y. Feng, Corey W. Speers, Lori Pierce, John Bennett, Karen J. Taylor. Validation of Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) in a meta-analysis of three randomized controlled trials of breast conserving surgery +/- radiotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS4-03.

Evaluating the Short-term Environmental and Clinical Effects of a Radiation Oncology Department's Response to the COVID-19 Pandemic

PURPOSE

During the COVID-19 pandemic, many radiation oncology departments worldwide adopted the use of shorter and more intense hypofractionated regimens. Hospital foot traffic was reduced through virtual care. This study's primary objective was to assess the collective environmental effect of these strategic changes by identifying sources of carbon dioxide equivalents (CO₂e). The rate of radiation-related adverse events from the increased use of hypofractionated treatments was assessed.

METHODS AND MATERIALS

All patients treated with external beam radiation therapy from April 1, 2019, to March 31, 2021, at our single institution were identified (n = 10,175) along with their radiation therapy visits (176,423 fractions) and unplanned visits to the radiation nursing clinic or emergency department. Out-patient hospital and virtual visits (n = 75,853) during this same period were also analyzed. Environmental effect measures, including linear accelerator power usage, patient travel distances, and personal protection equipment consumption were all converted into CO₂e.

RESULTS

The use of curative hypofractionated regimens increased from 17% to 27% during the pandemic year. Carbon footprint was reduced by 39% during the pandemic year (1,332,388 kg CO₂e) compared with the prepandemic year (2,024,823 kg CO₂e). Comparing patients in the prepandemic versus pandemic year, there was a significant reduction in the proportion of hypofractionated patients who needed a visit to either the radiation nursing clinic (39% vs 25%; P < .001) or emergency department (6% vs 2%; P < .001) during and within 90 days of radiation therapy.

CONCLUSIONS

This is the first study to demonstrate the environmental benefits of increased use of hypofractionated regimens and virtual care, while assuring that there was no added acute radiation-related adverse event. Our findings support their continued use as one of many long-term strategies to reduce the environmental footprint of health care delivery.

Physiological and metabolic toxicity of polystyrene microplastics to Dunaliella salina

The toxicity of microplastics (MPs) to marine microalgae has raised much concern. However, research at metabolic level is quite limited. In this study, the physiological and metabolic effects of polystyrene (PS) and aged polystyrene (A-PS) MPs on Dunaliella salina were investigated. Both PS and A-PS inhibited the growth of microalgae, but promoted the pigment synthesis in algal cells. The oxidative stress analysis indicated that PS and A-PS induced high production of reactive oxygen species (ROS), and caused oxidative damage to algal cells. Particularly, the highest ROS level in PS and A-PS groups were 1.70- and 2.24-fold of that in the control group, respectively. Untargeted metabolomics analysis indicated that PS and A-PS significantly increased the differential metabolites. Compared with the control group, the significant upregulation of glycerophospholipids metabolites illustrated that severe membrane lipid peroxidation occurred in the MPs groups. Metabolic pathways analysis showed that PS and A-PS perturbed the amino acid-related metabolic pathways. In particular, the amino acid biosynthesis and ATP-binding cassette (ABC) transporter pathways were significantly upregulated, thus promoting nitrogen storage and transmembrane transport in Dunaliella salina. Transmembrane transport requires a large amount of ATP; as a result, algal cell division is inhibited. In addition, A-PS stimulated more active glutathione metabolism than PS. These results enrich the understanding of the toxicity of PS MPs to microalgae at the metabolic level, and are helpful for further assessing the ecological impacts of MPs on microalgae.

CD8+ Tumor-Infiltrating Lymphocyte Abundance Is a Positive Prognostic Indicator in Nasopharyngeal Cancer

PURPOSE

Tumor-infiltrating lymphocytes (TIL) are immune cell populations found within tumors, critical in the antigen-specific host immune response. In this study, we aimed to elucidate the prognostic significance of CD3+, CD4+, and CD8+ TILs in nasopharyngeal cancer (NPC).

EXPERIMENTAL DESIGN

Immune cell infiltration was quantified in NPC samples (n = 50) using RNA-sequencing (RNA-seq) data based on rearranged T-cell receptor (TCR) reads and the Estimation of Stromal and Immune cells in malignant tumors using expression data (ESTIMATE) immune score tool. The differential abundances of TIL subset populations were also characterized through IHC staining of formalin-fixed, paraffin-embedded samples from a training cohort (n = 35), which was a subset of the RNA-seq cohort (n = 50).

RESULTS

In the RNA-seq cohort, patients with higher rearranged TCR reads experienced superior 5- and 10-year overall survival (OS; P < 0.001), and disease-free survival (DFS; P < 0.001). Similarly, patients with higher ESTIMATE immune scores experienced superior 5- and 10-year OS (P = 0.024) and DFS (P = 0.007). In the training cohort, high abundances of CD8+ TILs were significantly associated with improved 5- and 10-year OS (P = 0.003) and DFS (P = 0.005). These findings were corroborated in an independent validation cohort (n = 84), and combined analysis of the training and validation cohorts [n = 119 (35+84)], which further demonstrated improved 5- and 10-year survival in terms of locoregional control (P < 0.001) and distant metastasis (P = 0.03).

CONCLUSIONS

Taken together, our study highlights the prognostic value of CD8+ TILs in NPC, and the potential of future investigations into cellular-based immunotherapies employing CD8+ lymphocytes.

Forecasting Institutional LINAC Utilization in Response to Varying Workload

ObjectivesPandemics, natural disasters, and other unforeseen circumstances can cause short-term variation in radiotherapy utilization. In this study, we aim to develop a model to forecast linear accelerator (LINAC) utilization during periods of varying workloads. Methods: Using computed tomography (CT)-simulation data and the rate of new LINAC appointment bookings in the preceding week as input parameters, a multiple linear regression model to forecast LINAC utilization over a 15-working day horizon was developed and tested on institutional data. Results: Future LINAC utilization was estimated in our training dataset with a forecasting error of 3.3%, 5.9%, and 7.2% on days 5, 10, and 15, respectively. The model identified significant variations (≥5% absolute differences) in LINAC utilization with an accuracy of 69%, 62%, and 60% on days 5, 10, and 15, respectively. The results were similar in the validation dataset with forecasting errors of 3.4%, 5.3%, and 6.2% and accuracy of 67%, 60%, and 58% on days 5, 10, and 15, respectively. These results compared favorably to moving average and exponential smoothing forecasting techniques. Conclusions: The developed linear regression model was able to accurately forecast future LINAC utilization based on LINAC booking rate and CT simulation data, and has been incorporated into our institutional dashboard for broad distribution. Advances in knowledge: Our proposed linear regression model is a practical and intuitive approach to forecasting short-term LINAC utilization, which can be used for resource planning and allocation during periods with varying LINAC workloads.

[Incidence and risk factors of thromboembolism in patients with lung cancer receiving immunotherapy]

Objective: To evaluate the incidence of thromboembolism in a cohort of patients with lung cancer who received immune checkpoint inhibitors (ICIs), and explore relevant clinical risk factors. Methods: We retrospectively collected and analyzed the clinical data of patients with confirmed primary lung cancer and treated with ICIs between March 2018 and June 2021 at three hospitals in China (Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Fudan University Shanghai Cancer Center and Zhongshan Hospital of Fudan University). The cumulative incidence and risk factors of thromboembolism in these patients were analyzed using a competitive risk model. Results: A total of 804 patients were enrolled, there were 623 males and 181 females, with a median age of 59 years (ranged 28-86 years). Of these, 62 patients encountered 65 thromboembolic events, including 51 venous thromboembolism events (VTE) and 14 arterial thromboembolism events. The cumulative incidence of thromboembolism events at 3, 6, 12 and 24 months were 4.3%, 6.1%, 10.1% and 16.8%, respectively. And the cumulative incidence of venous thromboembolism events at 3, 6, 12 and 24 months were 3.4%, 4.7%, 9.0% and 13.3%, respectively. Multivariate analysis showed that history of thromboembolism (HR=6.345, 95%CI: 2.917-13.802,P<0.001),liver metastasis (HR=2.249, 95%CI: 1.123-4.502,P=0.022) and peripherally inserted central venous catheter (HR=3.674, 95%CI: 1.751-7.712, P<0.001) were independent risk factors for venous thromboembolism during ICIs therapy in patients with lung cancer. Conclusions: Patients with lung cancer under ICIs therapy are at high risk of thromboembolism. And history of thromboembolism, liver metastasis and peripherally inserted central venous catheter are risk factors of venous thromboembolism.

The mutation spectrum of PD-related genes in early-onset Parkinson's disease in ethnic Chinese

BACKGROUND

Recent genetic progress has shown many causative/risk genes linked to Parkinson's disease (PD), mainly in patients of European ancestry. The study aimed to investigate the PD-related genes and determine the mutational spectrum of early-onset PD in ethnic Chinese.

METHODS

In this study, whole-exome sequencing and/or gene dosage analysis were performed in 704 early-onset PD (EOPD) patients (onset age ≤ 45 years) and 1866 controls. Twenty-six PD-related genes and 20 other genes linked to neurodegenerative and lysosome diseases were analyzed.

RESULTS

We identified 82 (11.6%, 82/704) EOPD patients carrying rare pathogenic/ likely pathogenic variants in PD-related genes. The mutation frequency in autosomal recessive inheritance EOPD (AR-EOPD, 42.9%, 27/63) was much higher than that in autosomal dominant inheritance EOPD (AD-EOPD, 0.9%, 12/110) or sporadic EOPD (8.1%, 43/531). Bi-allelic mutations in PRKN were the most frequent, accounting for 5.1% of EOPD cases. Three common pathogenic variants, p.A53V in SNCA, p.G284R in PRKN, and p.P53Afs*38 in CHCHD2, occur exclusively in Asians. The putative damaging variants from GBA, PRKN, DJ1, PLA2G6, and GCH1 contributed to the collective risk for EOPD. Notably, the protein-truncating variants in CHCHD2 were enriched in EOPD, especially for p.P53Afs*38, which was also found in three patients from an independent cohort of patients with late-onset PD (n=1300). Functional experiments confirmed that truncated CHCHD2 variants cause loss of function and are linked to mitochondrial dysfunction.

CONCLUSIONS

Our study reveals that the genetic spectrum EOPD in Chinese, which may help develop genetic scanning strategies, provided more evidence supporting CHCHD2 in PD.

Microbial community mediates hydroxyl radical production in soil slurries by iron redox transformation

The generation of reactive oxygen species (ROS) mediated by minerals and/or microorganisms plays a vital but underappreciated role in affecting carbon and nutrient cycles at soil-water interfaces. It is currently unknown which interactions between microbial communities and iron (Fe) minerals produce hydroxyl radical (HO^•), which is the strongest oxidant among ROS. Using a series of well-controlled anoxic incubations of soil slurries, we demonstrated that interactions between microbial communities and Fe minerals synergistically drove HO^• production (up to ∼100 nM after 21-day incubation). Microorganisms drove HO^• generation in anoxic environments predominantly by modulating iron redox transformation that was more prominent than direct production of ROS by microorganisms. Among the microbial communities, Geobacter, Paucimonas, Rhodocyclaceae_K82, and Desulfotomaculum were the key genera strongly affecting HO^• production. In manured soils, the former two species had higher abundances and were crucial for HO^• production. In contrast, the latter two species were mainly abundant and important in soils with mineral fertilizers. Our study suggests that abundant highly reactive oxidant HO^• can be generated in anoxic environments and the microbial community-mediated redox transformations of iron (oxyhydr)oxides may be responsible for the HO^• production. These findings shed light on the microbial generation of HO^• in fluctuating redox environments and on consequences for global C and nutrient cycling.

Single and combined toxicity of polystyrene nanoplastics and copper on Platymonas helgolandica var. tsingtaoensis: Perspectives from growth inhibition, chlorophyll content and oxidative stress

The combined toxic effects of nanoplastics and heavy metals on aquatic organisms have attracted widespread attention; however, the results are inconsistent and the mechanisms remain unclear. In this study, the single and combined toxicity effects of Cu and two types of polystyrene nanoplastics (PS-NPs; 50 nm PS and 55 nm PS-COOH) on Platymonas helgolandica var. tsingtaoensis were investigated, including growth inhibition, chlorophyll content, and oxidative stress. An adverse dose-response relationship on growth inhibition was found in the Cu treatment groups, which was related to the decrease in chlorophyll content and damage to cell membranes. The growth inhibitory effect of PS-NPs on microalgae increased with exposure time and concentration, and no significant difference was found in the two types of PS-NPs because of the negligible contribution of functional groups. A more significant increase in chlorophyll content was found in PS treatments than in PS-COOH treatments at 96 h because of the microscale aggregates formed by PS. Higher concentrations (≥ 50 mg/L) of PS-NPs caused membrane lipid peroxidation, which might be responsible for growth inhibition. In the combined exposure experiments, a synergistic effect on the growth inhibition rate was obtained using the independent action model and Abbott model. Combined exposure triggered more severe oxidative damage to the microalgae. Adsorption experiment results showed that there was no adsorption between PS-NPs and Cu, while the interaction of Cu and algal cells could be promoted due to the presence of the PS-NPs, which explained the increasing combined toxicity. This study could improve our understanding of the combined toxicity of nanoplastics and heavy metals and could provide a new explanation for the mechanism of combined toxicity.

Intravenous Injection of Coronavirus Disease 2019 (COVID-19) mRNA Vaccine Can Induce Acute Myopericarditis in Mouse Model

BACKGROUND

Post-vaccination myopericarditis is reported after immunization with coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccines. The effect of inadvertent intravenous injection of this vaccine on the heart is unknown.

METHODS

We compared the clinical manifestations, histopathological changes, tissue mRNA expression, and serum levels of cytokine/chemokine and troponin in Balb/c mice at different time points after intravenous (IV) or intramuscular (IM) vaccine injection with normal saline (NS) control.

RESULTS

Although significant weight loss and higher serum cytokine/chemokine levels were found in IM group at 1-2 days post-injection (dpi), only IV group developed histopathological changes of myopericarditis as evidenced by cardiomyocyte degeneration, apoptosis, and necrosis with adjacent inflammatory cell infiltration and calcific deposits on visceral pericardium, although evidence of coronary artery or other cardiac pathologies was absent. Serum troponin level was significantly higher in IV group. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antigen expression by immunostaining was occasionally found in infiltrating immune cells of the heart or injection site, in cardiomyocytes and intracardiac vascular endothelial cells, but not skeletal myocytes. The histological changes of myopericarditis after the first IV-priming dose persisted for 2 weeks and were markedly aggravated by a second IM- or IV-booster dose. Cardiac tissue mRNA expression of interleukin (IL)-1β, interferon (IFN)-β, IL-6, and tumor necrosis factor (TNF)-α increased significantly from 1 dpi to 2 dpi in the IV group but not the IM group, compatible with presence of myopericarditis in the IV group. Ballooning degeneration of hepatocytes was consistently found in the IV group. All other organs appeared normal.

CONCLUSIONS

This study provided in vivo evidence that inadvertent intravenous injection of COVID-19 mRNA vaccines may induce myopericarditis. Brief withdrawal of syringe plunger to exclude blood aspiration may be one possible way to reduce such risk.

LUMINA: A prospective trial omitting radiotherapy (RT) following breast conserving surgery (BCS) in T1N0 luminal A breast cancer (BC)

LBA501

Background: Adjuvant breast RT is usually prescribed following BCS to reduce the risk of local recurrence (LR). However, this treatment is inconvenient, costly, and associated with acute and late toxicity. Traditional clinical pathological factors (CPFs) alone are limited in their ability to identify women with a low enough risk of LR to omit RT. Molecular defined intrinsic subtypes of BC provide additional prognostic information with luminal A having the lowest risk of recurrence. A retrospective analysis of a previous trial suggested that women >60 years with luminal A grade 1-2 T1N0 BC treated by BCS and endocrine therapy alone had a low rate of LR ( JCO 2015; 33:2035). The utility of identifying luminal A subtype combined with CPFs has not been prospectively evaluated for its ability to guide RT decision-making. Methods: A prospective multicenter cohort study was performed. Eligibility criteria were: women ≥ 55 years; having undergone BCS for grade 1-2 T1N0 BC; ≥ 1mm margins of excision; luminal A subtype (defined as: ER ≥ 1%, PR>20%, HER2 negative and Ki67 ≤ 13.25%); and treated with adjuvant endocrine therapy. ER, PR and HER2 were performed locally as per ASCO guidelines. Patients meeting clinical eligibility with ER ≥ 1%, PR>20%, HER2 negative BC were registered and had Ki67 immunohistochemistry performed centrally in one of three Canadian laboratories using International Ki67 Working Group methods. Proficiency testing between laboratories was performed yearly. Patients with Ki67 ≤ 13.25% were enrolled in the trial and were assigned to not receive RT. The primary outcome was LR defined as time from enrollment to any invasive or non-invasive cancer in the ipsilateral breast. Assuming a 5-year LR rate of 3.5%, 500 patients were required to show that the upper bound of a two sided 90% (one-sided 95%) confidence interval (CI) was <5%. Patients were followed every six months for the first two years and then yearly. The probability of LR was estimated using the cumulative incidence function with death as a competing risk. Secondary outcomes were contralateral BC; relapse free survival (RFS) based on any recurrence; disease free survival (DFS) based on any recurrence, second cancer or death; and overall survival (OS). Results: From August 2013 to July 2017, 501 of 727 registered patients from 26 centers had a Ki67 ≤ 13.25% and were enrolled. Median follow-up was 5 years. Median age was 67 and 442 (88%) patients were <75 years. Median tumor size was 1.1 cm. The 5-year rate of LR satisfied our pre-specified boundary (see Table). Conclusions: Women ≥ 55 years with grade 1-2 T1N0 luminal A BC following BCS treated with endocrine therapy alone had very low rates of LR at 5 years and are candidates for omission of RT. Clinical trial information: NCT01791829. [Table: see text]

Patient consent preferences on sharing personal health information during the COVID-19 pandemic: "the more informed we are, the more likely we are to help"

Background

Rapid ethical access to personal health information (PHI) to support research is extremely important during pandemics, yet little is known regarding patient preferences for consent during such crises. This follow-up study sought to ascertain whether there were differences in consent preferences between pre-pandemic times compared to during Wave 1 of the COVID-19 global pandemic, and to better understand the reasons behind these preferences.

Methods

A total of 183 patients in the pandemic cohort completed the survey via email, and responses were compared to the distinct pre-pandemic cohort (n = 222); all were patients of a large Canadian cancer center. The survey covered (a) broad versus study-specific consent; (b) opt-in versus opt-out contact approach; (c) levels of comfort sharing with different recipients; (d) perceptions of commercialization; and (e) options to track use of information and be notified of results. Four focus groups (n = 12) were subsequently conducted to elucidate reasons motivating dominant preferences.

Results

Patients in the pandemic cohort were significantly more comfortable with sharing all information and biological samples (90% vs. 79%, p = 0.009), sharing information with the health care institution (97% vs. 83%, p < 0.001), sharing information with researchers at other hospitals (85% vs. 70%, p < 0.001), sharing PHI provincially (69% vs. 53%, p < 0.002), nationally (65% vs. 53%, p = 0.022) and internationally (48% vs. 39%, p = 0.024) compared to the pre-pandemic cohort. Discomfort with sharing information with commercial companies remained unchanged between the two cohorts (50% vs. 51% uncomfortable, p = 0.58). Significantly more pandemic cohort patients expressed a wish to track use of PHI (75% vs. 61%, p = 0.007), and to be notified of results (83% vs. 70%, p = 0.012). Thematic analysis uncovered that transparency was strongly desired on outside PHI use, particularly when commercialization was involved.

Conclusions

In pandemic times, patients were more comfortable sharing information with all parties, except with commercial entities, where levels of discomfort (~ 50%) remained unchanged. Focus groups identified that the ability to track and receive results of studies using one’s PHI is an important way to reduce discomfort and increase trust. These findings meaningfully inform wider discussions on the use of personal health information for research during global crises.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12910-022-00790-z.

Magnesium-L-threonate exhibited a neuroprotective effect against oxidative stress damage in HT22 cells and Alzheimer’s disease mouse model

BACKGROUND

Oxidative stress results in the production of excess reactive oxygen species (ROS) and triggers hippocampal neuronal damage as well as occupies a key role in the pathological mechanisms of neurodegenerative disorders such as Alzheimer’s disease (AD). A recent study confirmed that magnesium had an inhibitory effect against oxidative stress-related malondialdehyde in vitro. However, whether Magnesium-L-threonate (MgT) is capable of suppressing oxidative stress damage in amyloid β (Aβ)_25-35-treated HT22 cells and the AD mouse model still remains to be investigated.

AIM

To explore the neuroprotective effect of MgT against oxidative stress injury in vitro and in vivo, and investigate the mechanism.

METHODS

Aβ_25-35-induced HT22 cells were preconditioned with MgT for 12 h. APPswe/PS1dE9 (APP/PS1) mice were orally administered with MgT daily for 3 mo. After MgT treatment, the viability of Aβ_25-35-treated HT22 cells was determined via conducting cell counting kit-8 test and the cognition of APP/PS1 mice was measured through the Morris Water Maze. Flow cytometry experiments were applied to assess the ROS levels of HT22 cells and measure the apoptosis rate of HT22 cells or hippocampal neurons. Expression of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), hypoxia-inducible factor (HIF)-1α, NADPH oxidase (NOX) 4, Aβ_1-42 and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway proteins was quantified by Western blot.

RESULTS

In vitro data confirmed that Aβ_25–35-induced HT22 cells had a significantly lower cell viability, higher ROS level and higher apoptosis rates compared with those of control cells (all P < 0.001). MgT prevented the Aβ_25-35-triggered oxidative stress damage by elevating viability and decreasing ROS formation and apoptosis of HT22 cells (all P < 0.001). APP/PS1 mice exhibited worse cognitive performance and higher apoptosis rate of hippocampal neurons than wild-type (WT) mice (all P < 0.01). Meanwhile, significant higher expression of Aβ_1-42 and NOX4 proteins was detected in APP/PS1 mice than those of WT mice (both P < 0.01). MgT also ameliorated the cognitive deficit, suppressed the apoptosis of hippocampal neuron and downregulated the expression of Aβ_1-42 and NOX4 proteins in APP/PS1 mouse (all P < 0.05). Moreover, MgT intervention significantly downregulated HIF-1α and Bax, upregulated Bcl-2 and activated the PI3K/Akt pathway both in vitro and in vivo (all P < 0.05).

CONCLUSION

MgT exhibits neuroprotective effects against oxidative stress and hippocampal neuronal apoptosis in Aβ_25-35-treated HT22 cells and APP/PS1 mice.

Abstract P2-08-01: Validation of a 16-gene genomic signature to identify early-stage invasive breast cancer patients who may omit radiotherapy

Background While whole breast radiotherapy has been standard of care for invasive breast cancer patients treated with breast conserving surgery, not all women may benefit from radiotherapy. Recently, we demonstrated that a 16-gene signature named Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) could identify breast cancer patients with HR+, HER2- tumors treated with breast conserving surgery alone with a 10-year locoregional recurrence risk of less than 10%. Methods In this study, we apply the signature to patients enrolled in the Princess Margaret Trial, a randomized trial where patients age 50 years or older were randomized to radiotherapy and tamoxifen or tamoxifen alone after breast conserving surgery. Tissue from 132 patients with HR+, HER2- tumors were available for gene expression analysis. Results For women treated with tamoxifen alone after breast conserving surgery, POLAR identified low risk women with a 7% risk of locoregional recurrence at 10 years. Comparison to POLAR-low patients treated with adjuvant radiotherapy did not demonstrate a significant benefit from radiotherapy (HR=1.5[0.14-16], p=0.74). POLAR-high patients not treated with radiotherapy had a 22% risk of locoregional recurrence at 10 years. Comparison to POLAR-high patients treated with adjuvant radiotherapy demonstrated a significant benefit from standard radiotherapy (HR=0.25[0.07-0.92], p=0.038). Conclusions These data suggest that the POLAR genomic signature may be used to identify patients with a low risk of locoregional recurrence without significant benefit from adjuvant radiotherapy. Patients with low POLAR scores may potentially be candidates for radiation therapy omission when treated with breast conserving surgery and tamoxifen.

Citation Format: Anthony Fyles, S. Laura Chang, Katrina Rey-McIntyre, Wei Shi, Felix Feng, Corey Speers, Lori Pierce, David McCready, Fei-Fei Liu. Validation of a 16-gene genomic signature to identify early-stage invasive breast cancer patients who may omit radiotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-08-01.

Physician Champions of Quality and Safety: Perspectives of MD Quality and Safety Leads to Drive Quality Innovation at an Academic Hospital

While the importance of physician involvement in organizational quality and safety (Q&S) activities has been well established, a paucity of information exists on tangible supports needed to effectively execute this role. Interviews with 13 MD Q&S leads uncovered common enablers, including valuing Q&S work academically, hiring skilled collaborators, ensuring appropriate power and authority to advance Q&S initiatives, facilitating connections, emphasizing culture change and strong action by leadership. To operationalize these enablers and drive quality innovation, organizations should prioritize the identification and appointment of MD Q&S leads for each department/division and facilitate their assembly as a formal physician Q&S committee.

Radiation Oncology Fellowship: a Value-Based Assessment Among Graduates of a Mature Program

The University of Toronto - Department of Radiation Oncology (UTDRO) has had a well-established Fellowship Program for over 20 years. An assessment of its graduates was conducted to evaluate training experience and perceived impact on professional development. Graduates of the UTDRO Fellowship Program between 1991 and 2015 were the focus of our review. Current employment status was collected using online tools. A study-specific web-based questionnaire was distributed to 263/293 graduates for whom active e-mails were identified; questions focused on training experience, and impact on career progression and academic productivity. As a surrogate measure for the impact of UTDRO Fellowship training, a comparison of current employment and scholarly activities of individuals who obtained their Fellow of the Royal College of Physicians of Canada (FRCPC) designation in Radiation Oncology between 2000 and 2012, with (n = 57) or without (n = 230) UTDRO Fellowship training, was conducted. Almost all UTDRO Fellowship graduates were employed as staff radiation oncologists (291/293), and most of those employed were associated with additional academic (130/293), research (53/293), or leadership (68/293) appointments. Thirty-eight percent (101/263) of alumni responded to the online survey. The top two reasons for completing the Fellowship were to gain specific clinical expertise and exposure to research opportunities. Respondents were very satisfied with their training experience, and the vast majority (99%) would recommend the program to others. Most (96%) felt that completing the Fellowship was beneficial to their career development. University of Toronto, Department of Radiation Oncology Fellowship alumni were more likely to hold university, research, and leadership appointments, and author significantly more publications than those with FRCPC designation without fellowship training from UTDRO. The UTDRO Fellowship Program has been successful since its inception, with the majority of graduates reporting positive training experiences, benefits to scholarly output, and professional development for their post-fellowship careers. Key features that would optimize the fellowship experience and its long-term impact on trainees were also identified.

Effects of polystyrene and triphenyl phosphate on growth, photosynthesis and oxidative stress of Chaetoceros meülleri

The toxicity of microplastics to marine organisms has attracted much attention; however, studies of their effects on marine microalgae remain limited. Here, the effects of the single and combined toxicity of polystyrene (PS) and triphenyl phosphate (TPhP) on the cell growth, photosynthesis, and oxidative stress of Chaetoceros meülleri were investigated. PS inhibited growth of the algae cells and caused a dose-dependent effect on oxidative stress. The significantly high production of reactive oxygen species (ROS) induced severe cell membrane damage, as confirmed by high fluorescence polarization. However, there was no obvious decrease in chlorophyll a content, and 80 mg/L of PS significantly promoted chlorophyll a synthesis. The TPhP also inhibited cell growth, except at low concentrations (0.2-0.8 mg/L), which stimulated algae growth over 48 h. Moreover, no obvious decrease in chlorophyll a and maximal photochemical efficiency of PSII was found in the TPhP experimental groups except for 3.2 mg/L TPhP, where the rapid light curves showed a significantly reduced photosynthetic capacity of algae. In addition, TPhP caused high ROS levels at 96 h, resulting in cell membrane damage. Using the additive index and independent action methods, the combined toxic effects of PS and TPhP on the algae were evaluated as antagonistic; however, cell membrane damage caused by high ROS levels was still noticeable. This study has shown the potential toxicity of PS and TPhP to marine microalgae, and provided insights into the combined risk assessment of TPhP and microplastics in the marine environment.

Molybdenum Bioavailability and Asymbiotic Nitrogen Fixation in Soils are Raised by Iron (Oxyhydr)oxide-Mediated Free Radical Production

Nitrogen (N) fixation in soils is closely linked to microbially mediated molybdenum (Mo) cycling. Therefore, elucidating the mechanisms and factors that affect Mo bioavailability is crucial for understanding N fixation. Here, we demonstrate that long-term (26 years) manure fertilization increased microbial diversity and content of short-range ordered iron (oxyhydr)oxides that raised Mo bioavailability (by 2.8 times) and storage (by ∼30%) and increased the abundance of nifH genes (by ∼14%) and nitrogenase activity (by ∼60%). Nanosized iron (oxyhydr)oxides (ferrihydrite, goethite, and hematite nanoparticles) play a dual role in soil Mo cycling: (i) in concert with microorganisms, they raise Mo bioavailability by catalyzing hydroxyl radical (HO^•) production via the Fenton reactions and (ii) they increase Mo retention by association with the nanosized iron (oxyhydr)oxides. In summary, long-term manure fertilization raised the stock and bioavailability of Mo (and probably also of other micronutrients) by increasing iron (oxyhydr)oxide reactivity and intensified asymbiotic N fixation through an increased abundance of nifH genes and nitrogenase activity. This work provides a strategy for increasing biological N fixation in agricultural ecosystems.

Punicalagin attenuates osteoarthritis progression via regulating Foxo1/Prg4/HIF3α axis

BACKGROUND

Punicalagin (PUN) is a common anti-inflammatory polyphenol. However, the function and mechanism of PUN in osteoarthritis remains unknown.

METHODS

Chondrocytes were isolated from rats, and confirmed by toluidine blue staining and immunofluorescence. Chondrocytes were challenged by lipopolysaccharide (LPS), and rat osteoarthritis model was established by Hulth method. The secretion of inflammatory factors, cell viability and apoptosis were tested via enzyme linked immunosorbent assay (ELISA), MTT and flow cytometry. The levels of forkhead box O1 (Foxo1), proteoglycan 4 (Prg4), hypoxia-inducible factor-3α (HIF3α), autophagy-related genes or extracellular matrix (ECM)-related proteins were examined via quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot or immunohistochemistry. The cartilage tissue damage was assessed via hematoxylin-eosin (HE) staining, toluidine blue staining and terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick and labeling (TUNEL) staining.

RESULTS

LPS triggered inflammatory injury in chondrocytes. PUN promoted autophagy to mitigate LPS-induced inflammatory injury. Foxo1 silence attenuated the effect of PUN on LPS-mediated autophagy inhibition and inflammatory injury. Promotion of Prg4/HIF3α axis abolished the influence of Foxo1 knockdown on LPS-mediated chondrocytes injury. PUN mitigated the inflammatory injury in rat osteoarthritis model by promoting autophagy and inhibiting inflammation and ECM degradation via Foxo1/Prg4/HIF3α axis.

CONCLUSION

PUN attenuates LPS-induced chondrocyte injury and osteoarthritis progression by regulating Foxo1/Prg4/HIF3α axis.

Role of genetics in amyotrophic lateral sclerosis: a large cohort study in Chinese mainland population

Background

A large number of new causative and risk genes for amyotrophic lateral sclerosis (ALS) have been identified mostly in patients of European ancestry. In contrast, we know relatively little regarding the genetics of ALS in other ethnic populations. This study aims to provide a comprehensive analysis of the genetics of ALS in an unprecedented large cohort of Chinese mainland population and correlate with the clinical features of rare variants carriers.

Methods

A total of 1587 patients, including 64 familial ALS (FALS) and 1523 sporadic ALS (SALS), and 1866 in-house controls were analysed by whole-exome sequencing and/or testing for G4C2 repeats in C9orf72. Forty-one ALS-associated genes were analysed.

Findings

155 patients, including 26 (40.6%) FALS and 129 (8.5%) SALS, carrying rare pathogenic/likely pathogenic (P/LP) variants of ALS causative genes were identified. SOD1 was the most common mutated gene, followed by C9orf72, FUS, NEK1, TARDBP and TBK1. By burden analysis, rare variants in SOD1, FUS and TARDBP contributed to the collective risk for ALS (p<2.5e-6) at the gene level, but at the allelic level TARDBP p.Gly294Val and FUS p.Arg521Cys and p.Arg521His were the most important single variants causing ALS. Clinically, P/LP variants in TARDBP and C9orf72 were associated with poor prognosis, in FUS linked with younger age of onset, and C9orf72 repeats tended to affect cognition.

Conclusions

Our data provide essential information for understanding the genetic and clinical features of ALS in China and for optimal design of genetic testing and evaluation of disease prognosis.

Abstract MP233: Investigating Genotoxic-induced Innate Immune Pathways Leading To Heart Failure With Preserved Ejection Fraction For Developing Effective Treatments

Background: A hallmark of heart failure pathologies is excessive and cumulative DNA damage, leading to an increased and accelerated cardiac cellular senescence. We aimed to investigate the role of DNA breaks in inducing inflammation leading to adverse remodeling, premature senescence, and cardiac dysfunction leading to onset of Heart Failure with preserved Ejection Fraction (HFpEF), a specific type of disease prevalent in the aging population.

Results: We use heart-focused ionizing radiation, a novel in vivo technique to induce aging related DNA damage and onset of diastolic dysfunction and HFpEF (n= 4-5 per group & per species; animals used: Rattus norvegicus and Mus musculus). We performed functional analysis, histological tissue assessment and molecular investigations to evaluate and validate this novel animal model technique. DNA damage response is upregulated in aging-related Heart Failure, and here demonstrated in our novel heart-focused radiation technique. Using in vitro ionizing radiation exposure alters cardiomyocyte morphology and activates inflammation, leading to upregulation of fibrosis and senescence markers. Finally using experimental inhibitor compounds targeting the cGAS-STING axis of innate immunity, we show effective attenuation of this relevant pathway, leading to decreased systemic inflammation, cardiomyocyte remodeling, and senescence associated with DNA damage injury.

Conclusions: We present a novel technique to induce genotoxic outcomes and inflammation of the heart, leading to HFpEF pathology. We elucidate novel connections from the onset and accumulation of unresolved DNA damage, to activation of specialized innate immune cellular responses, and ultimately upregulation of cardiac tissue specific inflammation, fibrosis and senescence. Finally we demonstrate that antagonizing the cGAS-STING pathway could allow a precision medicine approach to treating genotoxic and inflammatory HFpEF.

Absence of Vaccine-enhanced Disease With Unexpected Positive Protection Against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by Inactivated Vaccine Given Within 3 Days of Virus Challenge in Syrian Hamster Model

BACKGROUND

Mass vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is ongoing amidst widespread transmission during the coronavirus disease-2019 (COVID-19) pandemic. Disease phenotypes of SARS-CoV-2 exposure occurring around the time of vaccine administration have not been described.

METHODS

Two-dose (14 days apart) vaccination regimen with formalin-inactivated whole virion SARS-CoV-2 in golden Syrian hamster model was established. To investigate the disease phenotypes of a 1-dose regimen given 3 days prior (D-3), 1 (D1) or 2 (D2) days after, or on the day (D0) of virus challenge, we monitored the serial clinical severity, tissue histopathology, virus burden, and antibody response of the vaccinated hamsters.

RESULTS

The 1-dose vaccinated hamsters had significantly lower clinical disease severity score, body weight loss, lung histology score, nucleocapsid protein expression in lung, infectious virus titers in the lung and nasal turbinate, inflammatory changes in intestines, and a higher serum neutralizing antibody or IgG titer against the spike receptor-binding domain or nucleocapsid protein when compared to unvaccinated controls. These improvements were particularly noticeable in D-3, but also in D0, D1, and even D2 vaccinated hamsters to varying degrees. No increased eosinophilic infiltration was found in the nasal turbinate, lung, and intestine after virus challenge. Significantly higher serum titer of fluorescent foci microneutralization inhibition antibody was detected in D1 and D2 vaccinated hamsters at day 4 post-challenge compared to controls despite undetectable neutralizing antibody titer.

CONCLUSIONS

Vaccination just before or soon after exposure to SARS-CoV-2 does not worsen disease phenotypes and may even ameliorate infection.

Tumor-Naïve Multimodal Profiling of Circulating Tumor DNA in Head and Neck Squamous Cell Carcinoma

PURPOSE

Circulating tumor DNA (ctDNA) enables personalized treatment strategies in oncology by providing a noninvasive source of clinical biomarkers. In patients with low ctDNA abundance, tumor-naïve methods are needed to facilitate clinical implementation. Here, using locoregionally confined head and neck squamous cell carcinoma (HNSCC) as an example, we demonstrate tumor-naïve detection of ctDNA by simultaneous profiling of mutations and methylation.

EXPERIMENTAL DESIGN

We conducted CAncer Personalized Profiling by deep Sequencing (CAPP-seq) and cell-free Methylated DNA ImmunoPrecipitation and high-throughput sequencing (cfMeDIP-seq) for detection of ctDNA-derived somatic mutations and aberrant methylation, respectively. We analyzed 77 plasma samples from 30 patients with stage I-IVA human papillomavirus-negative HNSCC as well as plasma samples from 20 risk-matched healthy controls. In addition, we analyzed leukocytes from patients and controls.

RESULTS

CAPP-seq identified mutations in 20 of 30 patients at frequencies similar to that of The Tumor Genome Atlas (TCGA). Differential methylation analysis of cfMeDIP-seq profiles identified 941 ctDNA-derived hypermethylated regions enriched for CpG islands and HNSCC-specific methylation patterns. Both methods demonstrated an association between ctDNA abundance and shorter fragment lengths. In addition, mutation- and methylation-based ctDNA abundance was highly correlated (r > 0.85). Patients with detectable pretreatment ctDNA by both methods demonstrated significantly worse overall survival (HR = 7.5; P = 0.025) independent of clinical stage, with lack of ctDNA clearance post-treatment strongly correlating with recurrence. We further leveraged cfMeDIP-seq profiles to validate a prognostic signature identified from TCGA samples.

CONCLUSIONS

Tumor-naïve detection of ctDNA by multimodal profiling may facilitate biomarker discovery and clinical use in low ctDNA abundance applications.