Circulating pre-treatment T-cell receptor repertoire as a predictive biomarker in advanced or metastatic non-small-cell lung cancer patients treated with pembrolizumab alone or in combination with chemotherapy

BACKGROUND

The circulating T-cell receptor (TCR) repertoire is a dynamic representation of overall immune responses in an individual.

MATERIALS AND METHODS

We prospectively collected baseline blood from patients treated with first-line pembrolizumab monotherapy or in combination with chemotherapy. TCR repertoire metrics were correlated with clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS) and immune-related adverse events (irAEs). We built a logistic regression classifier by fitting all four TCR-β repertoire metrics to the immune checkpoint inhibitor (ICI) CBR data. In the subsequent receiver operating characteristic (ROC) analysis of the resulting logistic regression model probabilities, the best cut-off value was selected to maximise sensitivity to predict CBR to ICI.

RESULTS

We observed an association between reduced number of unique clones and CBR among patients treated with pembrolizumab monotherapy (cohort 1) [risk ratio = 2.86, 95% confidence interval (CI) 1.04-8.73, P = 0.039]. For patients treated with pembrolizumab plus chemotherapy (cohort 2), increased number of unique clones [hazard ratio (HR) = 2.96, 95% CI 1.28-6.88, P = 0.012] and Shannon diversity (HR = 2.73, 95% CI 1.08-6.87, P = 0.033), and reduced evenness (HR = 0.43, 95% CI 0.21-0.90, P = 0.025) and convergence (HR = 0.41, 95% CI 0.19-0.90, P = 0.027) were associated with improved PFS, while only an increased number of unique clones (HR = 4.62, 95% CI 1.52-14.02, P = 0.007) were associated with improved OS. Logistic regression models combining the TCR repertoire metrics improved the prediction of CBR (cohorts 1 and 2) and were strongly associated with PFS (cohort 1, HR = 0.38, 95% CI 0.19-0.78, P = 0.009) and OS (cohort 2, HR = 0.20, 95% CI 0.05-0.76, P < 0.0001). Reduced TCR conversion was associated with increased frequency of irAEs needing systemic steroid treatment.

CONCLUSION

Combined pre-treatment circulating TCR metrics might serve as a predictive biomarker for clinical outcomes among patients with advanced non-small-cell lung cancer treated with pembrolizumab alone or in combination with chemotherapy.

Efficacy of online nutrition professional development for Early Childhood Education Care staff

Background

Early Childhood Education & Care (ECEC) services are a public health setting that influences the lifelong eating habits and health of young Australians. Over 1.3 million children attend ECEC for 30 hours/week. Overweight/obesity, a risk factor for chronic disease, has been associated with this setting. Research reports sub-optimal food provision, poor role modelling and a lack of nutrition training and confidence. Online nutrition education training was provided to ECEC staff, aiming to increase nutrition knowledge/confidence.

Methods

Training was evidence-based, informed by stakeholders and developed by tertiary nutrition experts. ECEC staff were recruited and randomised to intervention or control groups. The intervention group completed an online short course about whole-service approach to healthy eating of 2-3 hours duration. Nutrition knowledge/confidence were measured pre/post-intervention via a pre-validated, online survey. GLM was used to determine differences within and between groups adjusting for years of experience.

Results

Participants (n = 116) were mostly female, aged &gt;36 years, with &gt;10 years industry experience. Post-course, compared to the control group, intervention participants significantly increased confidence to offer 2 serves of grains/day and unsweetened cereals, a variety of vegetables and low-sodium foods, and solid fats were avoided. Confidence to avoid serving discretionary foods did not change and cakes/biscuits were offered frequently.

Conclusions

Following course completion, intervention participants demonstrated increased confidence to serve foods from core food groups, but both groups reported offering discretionary foods frequently. Some results are promising and may improve the nutritional value of food offered at ECEC, but it appears discretionary foods continue to be overprovided. Further research is required to identify the depth of training required to embed important nutrition education concepts in ECEC settings.

Key messages

Evidence-based nutrition education adopting a whole-service approach is effective in increasing ECEC staff nutrition knowledge and confidence to provide foods from core food groups. Further research is required to establish the level of nutrition education appropriate for ECEC staff to avoid the continuing overprovision of discretionary foods to young children.

0519 Mindfulness Based Therapy for Insomnia Improves Objective Markers of Sleep in the Elderly: Preliminary Data from the Mindfulness Sleep Therapy (MIST) Study

Introduction

Mindfulness-based treatment for insomnia (MBTI) is a viable intervention for improving poor sleep. We report preliminary data from an ongoing pre-registered, randomized controlled trial which investigates the effect of MBTI on elderly adults.

Methods

Participants above 50 years old with PSQI ≥ 5 were recruited and randomised into either MBTI or an active control group (Sleep hygiene education and exercise program, SHEEP) in sequential cohorts with about 20 participants per cohort (10 per group). Before and after the intervention, 1 night of portable polysomnography (PSG) and 1 week of actigraphy (ACT) and sleep diary (DIARY) data were collected. We report the ACT and DIARY results of the first 3 cohorts (n = 46, male = 23, mean age = 62.3, std = 6.3) and PSG data of the first 2 cohorts (n = 29, male = 12, mean age = 62.5, std = 5.7). Time in bed (TIB), total sleep time (TST), sleep onset latency (SOL), wake after sleep onset (WASO), and sleep efficiency (SE) were analysed with mixed-model repeated-measures ANOVA.

Results

We observed increases in TIBDIARY (F1,44 = 5.151, p &lt; .05) and SEDIARY (F1,44 = 22.633, p &lt; .0001), and significant reductions in SOLDIARY (F1,44 = 7.031, p &lt; .05) and WASODIARY (F1,39 = 7.411, p &lt; .05). In the actigraphy data, we found a significant interaction in SOLACT (F1,39 = 4.273, p &lt; .05) with an increase in SHEEP SOLACT (t18= 2.36, p &lt; .05). Significant reductions were also observed in WASOACT (F1,44 = 16.459, p &lt; .0001) Finally, we observed a reduction in SOLPSG (F1,26 = 5.037, p &lt;. 05). All other tests were non-significant.

Conclusion

Preliminary results suggest that both interventions lead to improvements in sleep with more pronounced effects in subjective sleep reports. Objective sleep data suggest that improvements in sleep is a result of improved sleep quality and not simply extending sleep opportunity. These preliminary data shows that MBTI may be a promising intervention for elderly individuals with sleep difficulties.

Support

This study was supported by an award from the 7th grant call of the Singapore Millennium Foundation Research Grant Programme

Effects of Geographic and Economic Variations on Global Cancer Burden

Background: Previous studies have stated that high-income countries tend to have the highest incidence and mortality for all types of cancer, while geographical factors are also linked to the prevalence of cancer. Only a few studies have explored the relevance of economic/geographical factors to the cancer epidemic integrally. Aim: This study aims to explore the diversities of the overall cancer epidemic rates made by geographic and economic variations respectively and their interaction effects, after adjusting gender, population structure. Methods: We collected 170 countries' epidemic data from WHO's 2012 GLOBOCAN project and economic classifications data from the World Bank in 2012. We applied generalized linear model to make 2-way ANOVA and to analyze the variations of 3 epidemic rates (age-standardized incidence, age-standardized mortality and prevalence) between 6 regions (Asia, Africa, Europe, North America, South America, and Oceania) and 4 income levels (high income, upper-middle income, lower-middle income and low income). We identified extreme rates and discuss their reasons and implications, and make suggestions regarding the situations. Results: Both geographic variation and economic variation were key factors for incidence and prevalence of global cancer burden, and the interaction between geographic and economic variations on incidence and prevalence was very strong. However, there was no significant association between income and mortality, and the interaction between geographic and economic variations on mortality was not obvious either. Using South America as the reference, only North America had significant higher incidence rate of cancer; no significant variation of mortality rates between regions was observed; North America and Europe had significant higher prevalence rates. Using low income as the reference, only high and upper-middle income had significant higher incidence rates; no significant variation of mortality rates between regions was observed; only high income had significant higher prevalence rates. Among high-income countries, incidence, mortality and prevalence rates in Europe were significantly higher than them in South America, Asia and Africa. Among countries in Europe, high-income country had significantly higher incidence rate than that in upper-middle cancer, and it also had significant higher prevalence rates than them in upper-middle and lower-middle countries. Conclusion: Overall, the cancer incidence and prevalence are significantly different due to the country's geographical location and economic level, but the mortality rate is not. Understanding the differences in geographical location and economic levels between countries and their interactions on the cancer epidemic would benefit the future global cancer prevention and treatment policy planning.

Strength measures are better than muscle mass measures in predicting health-related outcomes in older people: time to abandon the term sarcopenia?

There is no clear consensus on definition, cut-points or standardised assessments of sarcopenia. We found a lower limb strength assessment was at least as effective in predicting balance, mobility and falls in 419 older people as muscle mass-based measures of sarcopenia.

INTRODUCTION

There is currently no consensus on the definition, cut-points or standardised assessments of sarcopenia. This study aimed to investigate whether several published definitions of sarcopenia differentiate between older people with respect to important functional and health outcomes.

METHODS

Four hundred nineteen community-living older adults (mean age 81.2 ± 4.5, 49 % female) completed assessments of body composition (dual-energy X-ray absorptiometry), strength, balance, mobility and disability. Falls were recorded prospectively for a year using monthly calendars. Sarcopenia was defined according to four skeletal mass-based definitions, two strength-based definitions (handgrip or knee extensor force) and a consensus algorithm (low mass and low strength or slow gait speed). Obesity was defined according to percentage fat mass or waist circumference.

RESULTS

The four skeletal mass-based definitions varied considerably with respect to the percentage of participants classified as sarcopenic and their predictive accuracy for functional and health outcomes. The knee extension strength-based definition was equivalent to or better than the mass-based and consensus algorithm definitions; i.e. weaker participants performed poorly in tests of leaning balance, stepping reaction time, gait speed and mobility. They also had higher physiological fall risk scores and were 43 % more likely to fall at home than their stronger counterparts. Adding obesity to sarcopenia definitions identified participants with greater self-reported disability.

CONCLUSIONS

A simple lower limb strength assessment was at least as effective in predicting balance, functional mobility and falls in older people as more expensive and time-consuming muscle mass-based measures. These findings imply that functional terms such as muscle weakness or motor impairment are preferable to sarcopenia.

Tailored Nutrition Education in the Elderly Can Lead to Sustained Dietary Behaviour Change

OBJECTIVES

Evaluate a 4-week dementia specific nutrition education intervention to determine long term knowledge and healthy dietary behaviour changes in 72 elderly men and women.

DESIGN

A mixed method design used qualitative findings to triangulate quantitative within-subject changes to determine efficacy and sustained dietary behaviour change.

SETTING

Community.

PARTICIPANTS

72 independently-living individuals.

INTERVENTION

4-week dementia specific nutrition education intervention.

MEASUREMENTS

Change in participant attitude, confidence, dietary patterns, cooking behaviour, and knowledge were analysed within-subjects using non-parametric repeated-measures procedures. Significance level was set at 5% (α = 0.05). Effect size (ES) was reported and identified as small (S), medium (M) or large (L) if a significant change was observed.

RESULTS

Compared to before the nutrition education intervention participants had an increase in total knowledge (p < 0.001, ES = 0.972 (L)), consumed a greater variety of vegetables (p = 0.007, ES = 0.35 (M)), used less salt (p = 0.006, ES = -0.42 (M-L)) and increased spice use (p < 0.001, ES = 0.40 (M-L)). Participants overcame barriers to enable sustained change, held a positive view on healthy living and believed government should invest in this sector of the community. Sharing and socialisation emerged as important themes that increased program satisfaction.

CONCLUSION

The dementia specific nutrition program produced a large effect in knowledge improvement from pre to post, which was retained at follow up, consolidated observational and participatory learning which produced a moderate increase in healthy dietary behaviours which participants valued and sustained.

Castor bean seed ingestions: a state-wide poison control system's experience

CONTEXT

Ingestions of the seed of the castor bean plant (Ricinus communis) carries the risk of toxicity from ricin, a potent inhibitor of protein synthesis.

OBJECTIVE

We sought to describe characteristics of castor bean seed exposures reported to a state-wide poison control system.

METHODS

This was an observational case series. A state-wide poison control system's database was reviewed for exposures to castor bean plant seeds from 2001 to 2011. Case notes were reviewed and data collected, when available, included age, gender, circumstances surrounding exposure, number of castor beans consumed, whether beans were chewed or crushed, symptoms described, laboratory values (aspartate aminotransferase [AST], alanine aminotransferase [ALT], prothrombin time [PT] and international normalized ratio [INR]), duration of follow-up, treatment, and patient outcomes.

RESULTS

Eighty-four cases were identified. Ingestions were unintentional in 50 cases (59%) cases and intentional in 34 (40%) cases. A median of 10 seeds (range: 1-20) were ingested in intentional cases versus 1 seed (range: 1-40) in unintentional cases. In 49 (58%) of cases the seeds were reported to have been chewed or crushed. Gastrointestinal symptoms were the most commonly reported symptoms. Vomiting (n = 39), nausea (n = 24), diarrhea (n = 17), and abdominal pain (n = 16) predominated. One patient developed hematochezia and vomiting after reportedly ingesting and intravenously injecting castor bean seeds. Laboratory values were documented in 17 (20%) cases. Only one abnormality was noted; an asymptomatic patient one week following ingestion had AST/ALT of 93 U/L and 164 U/L, respectively. Ricinine was confirmed in the urine of two patients. Twenty-three (27%) cases received activated charcoal. Seventy-two (86%) of cases were calls from health care facilities or referred to health care facilities by the poison control center. Twenty-two (26%) cases were admitted for a median of 2 days (range: 1-10). Admitted cases ingested a median of 8.5 seeds (range: 1-20). Intentional ingestions were followed for median of 37.5 h (range: 0.5-285.5) while unintentional cases were followed for 14 h (range: 1-182). No delayed symptoms, serious outcomes, or deaths were reported.

DISCUSSION

Due to the presence of ricin, there is concern for serious outcomes after ingestions of the seeds of the castor bean plant. In this study GI symptoms were most commonly reported but serious morbidity or mortality was not present. The true risk of castor bean plant seed ingestions should continue to be re-evaluated.

CONCLUSION

In this retrospective review, gastrointestinal symptoms were the most common symptoms described after reported exposures to castor bean seeds. These exposures were not associated with serious morbidity, mortality, or delayed symptoms.

New evidence for, and challenges in, linking small CGG repeat expansion FMR1 alleles with Parkinson's disease

We recently reported a significant increase in the frequency of carriers of grey zone (GZ) alleles of FMR1 gene in Australian males with Parkinson's disease (PD) from Victoria and Tasmania. Here, we report data comparing an independent sample of 817 PD patients from Queensland to 1078 consecutive Australian male newborns from Victoria. We confirmed the earlier finding by observing a significant excess of GZ alleles in PD (4.8%) compared to controls (1.5%). Although both studies provided evidence in support of an association between GZ-carrier status and increased risk for parkinsonism, the existing evidence in the literature from screening studies remains equivocal and we discuss the need for alternative approaches to resolve the issue.

Clinical Efficacy and Effects of Xylitol Wipes on Bacterial Virulence

The aim of the study was to investigate whether xylitol-wipe use in young children prevented caries by affecting bacterial virulence. In a double-blinded randomized controlled clinical trial, 44 mother-child pairs were randomized to xylitol-wipe or placebo-wipe groups. Salivary mutans streptococci levels were enumerated at baseline, 6 months, and one year. Ten mutans streptococci colonies were isolated and genotyped from each saliva sample. Genotype-colonization stability, xylitol sensitivity, and biofilm formation of these isolates were studied. Despite a significant reduction in new caries at one year in the xylitol-wipe group, no significant differences were found between the two groups in levels of mutans streptococci. Children in the xylitol-wipe group had significantly fewer retained genotypes (p = 0.06) and more transient genotypes of mutans streptococci (p = 0.05) than those in the placebo-wipe group. At one year, there was no significant difference in the prevalence of xylitol-resistant genotypes or in biofilm formation ability of mutans streptococci isolates between the two groups. The mechanism of the caries-preventive effect of xylitol-wipe use may be related to the stability of mutans streptococci colonization. Further studies with genomic characterization methods are needed to determine specific gene(s) that account for the caries-preventive effect of xylitol.