Development and validation of open-source deep neural networks for comprehensive chest x-ray reading: a retrospective, multicentre study

BACKGROUND

Artificial intelligence (AI) systems for automated chest x-ray interpretation hold promise for standardising reporting and reducing delays in health systems with shortages of trained radiologists. Yet, there are few freely accessible AI systems trained on large datasets for practitioners to use with their own data with a view to accelerating clinical deployment of AI systems in radiology. We aimed to contribute an AI system for comprehensive chest x-ray abnormality detection.

METHODS

In this retrospective cohort study, we developed open-source neural networks, X-Raydar and X-Raydar-NLP, for classifying common chest x-ray findings from images and their free-text reports. Our networks were developed using data from six UK hospitals from three National Health Service (NHS) Trusts (University Hospitals Coventry and Warwickshire NHS Trust, University Hospitals Birmingham NHS Foundation Trust, and University Hospitals Leicester NHS Trust) collectively contributing 2 513 546 chest x-ray studies taken from a 13-year period (2006-19), which yielded 1 940 508 usable free-text radiological reports written by the contemporary assessing radiologist (collectively referred to as the "historic reporters") and 1 896 034 frontal images. Chest x-rays were labelled using a taxonomy of 37 findings by a custom-trained natural language processing (NLP) algorithm, X-Raydar-NLP, from the original free-text reports. X-Raydar-NLP was trained on 23 230 manually annotated reports and tested on 4551 reports from all hospitals. 1 694 921 labelled images from the training set and 89 238 from the validation set were then used to train a multi-label image classifier. Our algorithms were evaluated on three retrospective datasets: a set of exams sampled randomly from the full NHS dataset reported during clinical practice and annotated using NLP (n=103 328); a consensus set sampled from all six hospitals annotated by three expert radiologists (two independent annotators for each image and a third consultant to facilitate disagreement resolution) under research conditions (n=1427); and an independent dataset, MIMIC-CXR, consisting of NLP-annotated exams (n=252 374).

FINDINGS

X-Raydar achieved a mean AUC of 0·919 (SD 0·039) on the auto-labelled set, 0·864 (0·102) on the consensus set, and 0·842 (0·074) on the MIMIC-CXR test, demonstrating similar performance to the historic clinical radiologist reporters, as assessed on the consensus set, for multiple clinically important findings, including pneumothorax, parenchymal opacification, and parenchymal mass or nodules. On the consensus set, X-Raydar outperformed historical reporter balanced accuracy with significance on 27 of 37 findings, was non-inferior on nine, and inferior on one finding, resulting in an average improvement of 13·3% (SD 13·1) to 0·763 (0·110), including a mean 5·6% (13·2) improvement in critical findings to 0·826 (0·119).

INTERPRETATION

Our study shows that automated classification of chest x-rays under a comprehensive taxonomy can achieve performance levels similar to those of historical reporters and exhibit robust generalisation to external data. The open-sourced neural networks can serve as foundation models for further research and are freely available to the research community.

FUNDING

Wellcome Trust.

Molar-incisor hypomineralisation prevalence in a cohort of Australian children with type 1 diabetes

PURPOSE

Systemic diseases or drugs administered early in life may cause a disruption in amelogenesis and contribute to the qualitative defect of enamel described as molar-incisor hypomineralisation (MIH). Therefore, an increase in prevalence of MIH in children with type 1 diabetes (T1D) may be expected as this systemic disorder is commonly diagnosed in early childhood. The aim of this study was to determine the prevalence of MIH in a cohort of children with T1D and investigate diagnosis of MIH with T1D factors.

METHODS

Cross-sectional study of children with T1D recruited from paediatric diabetes clinics at the Women's and Children's Hospital (South Australia). A detailed medical history, comprehensive dental and MIH examination according to the European Academy of Paediatric Dentistry (EAPD) long form classification was collected for each child. All upper and lower first permanent molars and central incisors were scored.

RESULTS

A total number of 73 participants; 35 (47.95%) males were examined including 584 teeth. The mean age of the participants was 13.25 ± 2.58 years, with a mean age of diagnosis 7.75 ± 3.58 years, and a mean HbA1c of 8.5 ± 1.6%. 42 out of 73 children (54.8%) had enamel defects on at least one of the teeth examined. However, 19.2% met the criteria for MIH. Univariate and bivariate analyses were conducted but no significant associations were noted between MIH and risk factors including diabetes control (p > 0.1).

CONCLUSION

There was a high prevalence of enamel defects and MIH amongst children with T1D. More research is required to establish association between T1D and MIH.

Limited liver resections in the posterosuperior segments: international multicentre propensity score-matched and coarsened exact-matched analysis comparing the laparoscopic and robotic approaches

Background

Limited liver resections (LLRs) for tumours located in the posterosuperior segments of the liver are technically demanding procedures. This study compared outcomes of robotic (R) and laparoscopic (L) LLR for tumours located in the posterosuperior liver segments (IV, VII, and VIII).

Methods

This was an international multicentre retrospective analysis of patients who underwent R-LLR or L-LLR at 24 centres between 2010 and 2019. Patient demographics, perioperative parameters, and postoperative outcomes were analysed; 1 : 3 propensity score matching (PSM) and 1 : 1 coarsened exact matching (CEM) were performed.

Results

Of 1566 patients undergoing R-LLR and L-LLR, 983 met the study inclusion criteria. Before matching, 159 R-LLRs and 824 L-LLRs were included. After 1 : 3 PSM of 127 R-LLRs and 381 L-LLRs, comparison of perioperative outcomes showed that median blood loss (100 (i.q.r. 40–200) versus 200 (100–500) ml; P = 0.003), blood loss of at least 500 ml (9 (7.4 per cent) versus 94 (27.6 per cent); P < 0.001), intraoperative blood transfusion rate (4 (3.1 per cent) versus 38 (10.0 per cent); P = 0.025), rate of conversion to open surgery (1 (0.8 per cent) versus 30 (7.9 per cent); P = 0.022), median duration of Pringle manoeuvre when applied (30 (20–46) versus 40 (25–58) min; P = 0.012), and median duration of operation (175 (130–255) versus 224 (155–300); P < 0.001) were lower in the R-LLR group compared with the L-LLR group. After 1 : 1 CEM of 104 R-LLRs with 104 L-LLRs, R-LLR was similarly associated with significantly reduced blood loss and a lower rate of conversion to open surgery.

Conclusion

Based on a matched analysis of well selected patients, both robotic and laparoscopic access could be undertaken safely with good outcomes for tumours in the posterosuperior liver segments.

Hepatic transcriptome profiling according to growth rate reveals acclimation in metabolic regulatory mechanisms to cyclic heat stress in broiler chickens

Climate change has numerous effects on poultry that result in welfare concerns and economic losses in agricultural industries. However, the mechanisms underlying the acclimation to heat stress in poultry have not been comprehensively defined. Therefore, identifying associated patterns of gene regulation and understanding the molecular mechanisms of acclimation to a warmer environment will provide insights into the acclimation system of broiler chickens. We profiled differentially expressed genes (DEGs) associated with differences in growth performance under heat stress conditions in the liver tissues of broilers based on RNA sequencing data. The DEGs were identified by comparison to the gene expression levels of broilers exhibiting average growth at 28 d of age (D28A) and D36A relative to those at D21A. In D36A, 507 and 312 DEGs were up- and downregulated, respectively, whereas 400 and 156 DEGs were up- and downregulated in D28A, respectively. Pathway enrichment analysis further revealed that “fatty acid degradation” and “heat shock protein expression” were upregulated in broilers exhibiting a higher growth and weight, whereas “cell cycle arrest” and “amino acid metabolism” were downregulated. Transcriptome profiling revealed that the acclimatized group supplied fat and energy from the liver to tissues through the breakdown of fatty acids. Furthermore, homeostasis was maintained via heat shock proteins and antioxidant enzymes. The characterized candidate genes and mechanisms associated with the response to heat stress might serve as a foundation for improving the ability of broilers to acclimatize under heat stress conditions.

Probiotic characterization of Lactiplantibacillus plantarum HOM3204 and its restoration effect on antibiotic-induced dysbiosis in mice

The purpose of this study was to evaluate the probiotic characteristics of Lactiplantibacillus plantarum HOM3204 isolated from homemade pickled cabbage and to examine its restoration effect on antibiotic-induced dysbiosis in mice. Lact. plantarum HOM3204 tolerated simulated gastric and intestinal juices with a 99.38% survival rate. It also showed strong adhesion ability (3.45%) to Caco-2 cells and excellent antimicrobial activity against foodborne pathogens in vitro. For safety (antibiotic susceptibility) of this strain, it was susceptible to all the tested seven antibiotics. Lact. plantarum HOM3204 had good stability during storage, especially in cold and frozen conditions. Furthermore, Lact. plantarum HOM3204 significantly restored the gut microbiota composition by increasing the abundance of Lactobacilli and Bifidobacteria and decreasing Enterococci, and improved antioxidative function by raising the concentrations of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in serum of antibiotic-induced dysbiosis in mice. These results suggest that Lact. plantarum HOM3204 could be a potential probiotic as a functional food ingredient.

1104 Plasma Circulating Cell-Free Messenger RNA as a Potential Biomarker of Melanoma

Introduction

Blood-borne cell-free nucleic acids are increasingly emerging as significant non-invasive adjuncts to current methods of disease status evaluation in cancer patients. In this study, we sought to examine whether significant differences exist in the plasma transcriptomic profile of advanced melanoma patients with a high disease burden compared to patients with therapeutic response.

Method

Plasma circulating cell-free messenger ribonucleic acid (ccfmRNA) was extracted from twenty patients with stage IV melanoma receiving immunotherapy. Pathway focused gene expression analysis was performed. Patients were assessed with paired blood sample collection and CT scan assessments at baseline and at 3 months follow up. Response Evaluation Criteria in Solid Tumours (RECIST 1.1) was used for tumour burden estimation.

Results

In stage IV melanoma patients, CCL5, GZMB and MYD88 genes were significantly over-expressed (p < 0.05 versus healthy controls). In patients with high disease burden or progressive disease, CCL18, CCR1, CCR4, CD274, CSF2, and GBP1 genes were significantly over-expressed (p < 0.05 versus patients with therapeutic response). Finally, in stage IV melanoma patients with brain metastases, CCL18, CCR1, CCR4, CD274, CSF2, EGF, GBP1, and PTGS2 genes were significantly over-expressed (p < 0.05, versus patients without brain metastasis).

Conclusions

Significant differences were observed in the plasma transcriptomic profile between the various melanoma patient groups, and we postulate that these differences may be exploited to identify novel therapeutic targets or biomarkers relevant to melanoma. CCL4 and CCL5 are prognostic in melanoma, both genes had significantly higher expressions in low disease burden patients compared to patients with a high disease burden.

1095 The Utility of Plasma Circulating Cell-Free Messenger RNA as A Biomarker of Glioma: A Pilot Study

Introduction

Research into the potential utility of plasma-derived circulating-cell-free nucleic acids as non-invasive adjuncts to radiological imaging has been occasioned by the invasive nature of brain tumour biopsy. Circulating-cell-free messenger RNAs are short fragments of RNA present in blood. The objective of this study was to determine whether significant differences exist in the plasma transcriptomic profile of glioma patients relative to differences in their tumour characteristics, and also whether any observed differences were representative of synchronously obtained glioma samples and TCGA glioma derived RNA.

Method

Blood samples were collected from twenty-nine patients prior to tumour resection. Plasma-ccfmRNA and glioma derived RNA were extracted and profiled.

Results

BCL2L1, CXCL5, GZMB, HLA-A, HLA-C, IRF1, MYD88, TGFB1, TLR2, and TP53 genes were significantly over-expressed in glioma (high-grade-glioma-HGG and low-grade-glioma-LGG) patients (p < 0.05, versus control). BCL2L1, GZMB and HLA-A genes were significantly over-expressed in HGG patients (p < 0.05, versus LGG patients). There was positive correlation between the magnitude of fold change of differentially expressed genes in plasma and glioma derived RNA (Spearman r = 0.6344, n = 14, p = 0.017), and with the mean FPKM of TCGA glioma derived RNA samples (Spearman r = 0.4614, n = 19, p = 0.047). There was positive correlation between glioma radiographic tumour burden and the magnitude of fold change of CSF3 gene (r = 0.9813, n = 20, p < 0.001).

Conclusions

We identified significant differential expression of genes involved in cancer inflammation and immunity among patients with different glioma grades, and we identified positive correlation between the plasma transcriptomic profile and tumour samples, and with TCGA glioma derived RNA.

A case study exploring the 'real world' process of 'naturalizing' school playgrounds

Background: The aim of this study was to examine the lived experiences of teachers and administrators at two schools (one elementary Kindergarten-Grade 5 and one middle school, grades 6-8) following the 'naturalizing' of a portion of their schoolyard. Methods: A qualitative case study design was used. Focus groups and interviews allowed participants to express their rationale, identify implementation facilitators and barriers and critical processes/steps for realizing their naturalization goals. Researcher questions explored (1) factors which led to naturalizing the schoolyard, (2) key planning and process steps (3) challenges and successes experienced, and, (4) lessons learned. Findings: Six themes were identified as rationale for naturalizing including: re-integration of outdoor play into children's daily lives, pro-active mental health, opportunity for inclusion, nature as a positive space for learning, it fit with our values and principles, we had a need. Implementation was facilitated by having champions and support from multiple levels, adopting a phased approach, resources and having the buy-in to persevere over time. Significant challenges and 'how to' steps were also identified. Conclusions: Naturalizing schoolyards does not happen without a supportive context, significant time and effort. Implementation steps and issues were those commonly found in other school-based health promotion efforts.

The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Cardiovascular phenotyping of the first mouse model of Sarcoidosis

Introduction

Sarcoidosis is a potentially life-threatening, inflammatory, granulomatous disease that affects multiple organs including the heart. Heretofore, its unknown etiology had hindered the creation of experimental models and the understanding of the molecular mechanisms of pathogenesis behind it.

Purpose

To extensively phenotype the heart of the first mouse model of sarcoidosis created through deletion of the tuberous sclerosis 2 (Tsc2) gene in the CD11c-positive macrophage population.

Methods

Tsc2 fl/fl CD11c Cre+ (Tsc2-KO; n=7) and Tsc2 fl/fl CD11c Cre- (Tsc2-WT; n=7) mice were subjected to echocardiography at 25 weeks of age (woa) to assess myocardial dimensions and function. Hearts of 13 and 25woa animals were subjected to histological and immunological stains to assess tissue changes, subtype inflammatory infiltrates and examine the localization of key proteins shown to be re-distributed in patients.

Results

At 13 woa, Tsc2-KO animals show inflammatory infiltrates; subtyped mainly as macrophages as well as evidence of myocyte destruction. At 25 woa, the number of inflammatory cells is significantly higher and there is heavy fibrotic replacement primarily in the septum and trabeculae. Older animals also show giant cells and non-necrotizing granulomas. The hearts show heterogeneous gap junction remodeling known to constitute an arrhythmogenic substrate and lack of immunoreactive signal for the desmosomal protein plakoglobin from the cell-cell junctions just as described in patients. The left ventricular ejection fraction and LV morphology was not significantly different between the two groups (EF: 64±4% in Tsc2-KO vs 64±2% in Tsc2-WT; LV end-systolic diameter: 4.51±0.54 mm in Tsc2-KO vs 4.59±0.29 mm in Tsc2-WT). However, there was a strong trend towards increasing filling pressure (E/e'ratio; 14.24±4.01 vs 12.15±2.54) and mean pulmonary pressure (21±6 vs 18±3 mmHg) in Tsc2-KO mice compared to controls suggesting diastolic dysfunction.

Conclusion

Hearts of the Tsc2 fl/fl CD11c Cre+ animals show a phenotype highly reminiscent of cardiac sarcoidosis in patients. We anticipate that this model will be very useful in deciphering molecular mechanisms of pathogenesis as well as testing much-needed mechanism-based therapies.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation - PG/18/27/33616

Assessing the Utility of Ultrasound and Urinalysis for Patients with Possible Epididymo-Orchitis - A Retrospective Study

Purpose

Many experts recommend ordering an ultrasound and a urinalysis on all patients with scrotal pain. While the ultrasound may help diagnose a number of potential causes of scrotal pain, the urinalysis primarily has value in assessing for epididymo-orchitis. This study sought to evaluate the utility of these diagnostic tests for patients who presented to the emergency department (ED) with acute scrotal pain and possible epididymo-orchitis.

Patients and Methods

This was a single-center chart review of patients presenting to the ED with scrotal pain. Trained research assistants reviewed charts to obtain urinalysis and ultrasound results as well as diagnoses and treatments provided. Using the final diagnosis as a gold standard, the sensitivity and specificity of ultrasound and urinalysis were calculated for the diagnosis of epididymo-orchitis. Also, through a prespecified definition of “changed management,” we estimated the percentage of cases in which a urinalysis changed management of patients with acute scrotal pain.

Results

We identified 663 adult and pediatric patients who presented with scrotal pain during 2016. All patients had an ultrasound performed, and 458 (69.1%) had a urinalysis done. The sensitivity of urinalysis for epididymo-orchitis was 58.2% (95% CI 48.9% to 67.1%), and the specificity was 85.1% (95% CI 80.8% to 88.7%). For ultrasound, the sensitivity was 78.8% (95% CI 71.4% to 85.0%) and the specificity was 98.1% (95% CI 96.4% to 99.1%). In 24 of 458 cases (5.2% [95% CI 3.4% to 7.7%]) where a urinalysis was obtained, its results may have changed management of the patient.

Conclusion

The diagnosis of patients who present to the ED with scrotal pain is primarily driven by the ultrasound results. While the urinalysis may occasionally provide some benefit in the evaluation of patients with suspected epididymo-orchitis, the reflexive ordering of a urinalysis in patients with scrotal pain may be unnecessary.

P110 External ventricular drain-related infections: a single centre study

Objectives

To quantify the External Ventricular Drain-related infection (ERI) rate in a one year period at Cork University Hospital, and to identify any risk factors for infection.

Design

A retrospective audit of all External Ventricular Drains (EVDs) inserted in a one year period.

Subjects

All patients who had an EVD inserted between February 2017 and February 2018.

Methods

Patients were identified from operating theatre logbooks. All relevant data was obtained from a retrospective review of medical and operative records. ERI was defined as evidence of positive CSF culture.

Results

41 EVDs were inserted in a total of 30 patients during the study period. The average age was 52.9 years. 46.6% of patients were female. The average length of EVD insertion was 8.85 days. The most common reason for EVD insertion was subarachnoid haemorrhage (31.7%) followed by supratentorial tumour (24.4%). 78% of EVDs were antibiotic-impregnated. Average EVD sampling rate was 0.7. ERI rate was 1/41 (2.4%). The infection occurred in a patient who had an EVD inserted for haemorrhage secondary to an AVM which had remained in situ for 13 days. The patient subsequently developed problems with repeated shunt infections resulting in a nine-month hospital stay.

Conclusions

The ERI rate in our patient cohort was 2.4%. We recommend using a strict EVD sampling protocol to minimise manipulation of EVDs and where possible to limit the length of time an EVD remains in situ. EVD-related infections can result in lengthy hospital stays and increased healthcare costs.

Prevalence and Characteristics of Smoking Among School-Going Adolescents in Kuala Lumpur, Malaysia

Background: According to the World Health Organization (WHO) (2014), noncommunicable diseases (NCDs) such as cancer, cardiovascular disease and respiratory disease account for a majority of premature deaths in the Malaysian population. Tobacco smoking remains a leading risk factor for these diseases. Although there have been previous population-level studies which have highlighted adolescent smokers in Malaysia, little has been done to specifically ascertain smoking prevalence within a school-going population using objective measurement tools. Aim: This study aimed to identify the prevalence of school-going adolescent smokers in Kuala Lumpur via an objective measurement - expired carbon monoxide (CO) in parts per million (ppm). Methods: This study was a cross-sectional study that involved 2,679 high school-going adolescents aged between 13 to 18 years old in Kuala Lumpur, Malaysia. The level of exhaled CO (Smokerlyzer test) of all the participants was measured. Participants were also administered with a survey conducted right after the Smokerlyzer test to determine i) whether they smoked or not; ii) type of tobacco products used if smoked; iii) vaping or shisha usage; and iv) exposure to secondhand smoke. The categorization of smoking status was based on CO-ppm reading: ≤ 3 ppm (nonsmoker); 3 < ppm ≤ 6 (light smoker or nonsmoker breathing in poor air quality or passive smoke inhalation); ≥ 7 ppm (regular smoker with higher levels of CO in blood). Descriptive analysis was conducted to determine the demographics of the study population. Inferential analysis was carried out utilizing χ2 tests or Student t-tests to test associations between smoking status and other independent variables. One-way ANOVA test was conducted to compare the differences in CO-ppm readings. Results: The mean age of the adolescents (n=2,679) was 14.5 ± 1.2 years old (median: 14) and 55.1% were male. Interestingly, vaping was the most commonly used method of tobacco use among the studied adolescents, regardless of gender, followed by cigarettes and shisha. The mean CO-ppm reading for male adolescents was significantly higher than female adolescents. Passive smoke inhalation (exposure to secondhand smoke) was significantly associated with higher readings of CO-ppm. A significant association was determined between status of exposure to secondhand smoke and a history of usage of any form of tobacco products. Conclusion: The prevalence of smoking adolescents, regardless of gender, in Kuala Lumpur remains at a worrying state. Objective measurements such as Smokerlyzer test can be coupled with self-reported questionnaire in targeting adolescent smokers within a structured setting such as a school and can help form part of an effective school-based smoking cessation intervention program targeting adolescents in Malaysia. This is in line with efforts to make Malaysia a smoke-free nation by 2045.

Losing Themselves From Following Up: Barriers to Accessing Further Clinical Investigations for Women With Abnormal Clinical Breast Examination (CBE) Findings in Klang Valley, Malaysia

Background: Clinical breast examination (CBE) is one of the most accessible screening methods for breast cancer and widely used in the Malaysian public health system due to the wide availability of trained healthcare personnel and low costs; especially in government hospitals. However, discovery of an abnormal finding from the CBE does not necessarily translate into action for further clinical investigations. An understanding of the patients' motivations in decision making, which causes them to ignore the need for further clinical investigations despite abnormal findings in CBEs may be an important element to improve holistic cancer prevention efforts; of which early detection is a key strategy. Aim: The aim of this study was to investigate the barriers for women to receive follow-up care upon obtaining abnormal results for CBE. Methods: The National Cancer Society of Malaysia has an active ongoing public outreach program in which trained healthcare personnel conduct CBEs at various screening campaigns throughout the Klang Valley with a total of 1017 women screened in 2017. Women who were screened and found to have an abnormal finding from the CBE were referred for further investigations at a center of their choice. Women found to have an abnormal CBE finding were reached via a phone call to determine whether they had proceeded to i) get an appointment for further clinical examination; or ii) had already undergone a further clinical examination. Those who had done neither were interviewed via phone to determine their reasons for not proceeding with further clinical investigations despite an abnormal CBE finding. Results: Out of the 1017 women screened, 38 were found to have an abnormal CBE finding. Of them, 16 women had not sought further investigations. Qualitative interviews revealed that there strong issues that posed barriers to these women pursuing further investigations. These barriers included a lack of knowledge and understanding about breast cancer or rationale of undergoing a CBE; a lack of urgency pertaining to CBE results and feeling of embarrassment engaging with family members on facilitating attendance to the investigation. Conclusion: Significant barriers remain which deter women who have abnormal CBE findings from pursuing further clinical investigations which ultimately reduces the effectiveness of current breast cancer screening strategies. These findings may prove to be important for designing effective methods to encourage confirmatory clinical examination among those already found to have abnormal findings from tests such as the CBE.

Would You Like A Free Mammogram? Effectiveness of Utilizing WhatsApp As a Social Marketing Tool in Improving Uptake for a Free Mammography Service in Kuala Lumpur Malaysia

Background: Social media and messaging services are increasingly targeted by health providers as an avenue to spread health messages, increase awareness and also for social marketing. WhatsApp is a social media application which has wide penetration in Malaysia, with more than half the population relying on WhatsApp for news. Aim: This study aimed to determine the effectiveness of WhatsApp as a social marketing tool to increase uptake for a free mammography service for underprivileged women. Methods: This was a randomized clinical trial conducted in Kuala Lumpur, Malaysia. Individuals from the National Cancer Society of Malaysia database were randomized into 1 of 3 arms receiving a WhatsApp message; i) a poster of a free mammography service for underprivileged women; ii) a poster of the free mammography service for underprivileged women with a personal message from the Director of the National Cancer Society of Malaysia; and iii) the poster, personal message from the director and a specific Saturday screening date with the exhortation that there were only 40 places available for that date on a first-come first-serve basis. The outcomes of the trial were i) number of women who returned a call or WhatsApp message to the designated numbers; ii) number of women who booked an appointment for the mammography service; and iii) numbers of women who attended the appointment. Results: The number of calls and inquiries to designated numbers increased by more than 200% as a result of the WhatsApp messages. There were statistically significant differences between the three delivery arms; with the highest percentages of women booking and attending their mammography appointments coming from the arm which had a designated screening date with limited availability. Conclusion: WhatsApp was highly effective at increasing community penetration and marketing a free mammography service for underprivileged women in Kuala Lumpur. Messages with an appeal from a personage and with a specific date of “expiry” were more effective at getting the targeted group to avail themselves of the service.

Factors Associated With an Abnormal Mammogram Finding in Women Undergoing Screening in Kuala Lumpur, Malaysia

Background: Breast cancer is the most common cancer among Malaysian women, with a rising incidence from 16.5% in 2006%–17.7% in 2011. One of the key strategies in breast cancer control is early screening; of which mammography is a highly accurate tool, having been shown to reduce the number of mortality rates due to breast cancer up to 30%. However, mammography is often not as widely available in Malaysia; and in many local settings, healthcare providers have to limit screenings to only particular groups such as those with abnormal clinical breast examinations due to limited resources. Knowledge of other predictive factors may assist in further decision-making to prioritize patients for screening mammography in a low-resource setting. Aim: This study aimed to determine such predictive factors for abnormal mammogram findings among women who underwent mammography examination at a center in Kuala Lumpur, Malaysia. Methods: This was a cross-sectional study of women (n = 5491) who underwent a three-dimensional tomosynthesis mammography procedure at the Cancer and Health Screening Clinic, National Cancer Society of Malaysia (NCSM) in Kuala Lumpur, from Jan 2016 until Dec 2017 (2 years). Patients were surveyed on: i) age, ii) ethnicity, iii) family history of breast or any cancers, if any, iv) reproductive history (age of menarche, age of first delivery, age of menopause); and v) history of postmenopausal estrogen and hormone replacement therapy (HRT). Bivariate analysis was conducted by using χ2 tests in determining associations between variables and a multiple logistic regression model built to identify factors which were predictive of an abnormal mammogram finding (BI-RADS 4 & 5). Results: From the bivariate analysis; nulliparous status ( P = 0.02), a family history of breast cancer ( P = 0.04), and a history of postmenopausal hormone replacement therapy (HRT) ( P = 0.01) were determined to significantly associated with an abnormal mammogram finding. There were also significant ethnic differences between women who had abnormal mammogram findings; with Chinese women having highest odds of this (OR:3.22; 95% CI 1.86-5.74). Women within the age group of 45-54 (OR:1.84, 95% CI 1.19-3.12), a family history of breast cancer (OR 2.03, 95% CI 1.31-3.27) or any cancer (OR 1.56, 95% CI 1.06-2.94), age of menopause (OR 2.86; 95% CI 1.43-4.02) and age of first delivery above 30 (OR 1.73, 95% CI 1.26-3.45) were significantly associated with abnormal mammogram findings. Conclusion: Factors which predict abnormal mammogram findings in a Malaysian setting can be used as baseline evidence to formulate criteria which can be used to carry out targeted screening programs or even as cutoff criteria for focusing screening resources in resource-limited settings. This data may be of benefit in aiding healthcare providers in provisioning of services at a macro level as well as for frontline healthcare personnel in helping them profile women who should be focused on to be screened for the disease.

Hi, I Have Cancer, What Can I Do? An Analysis of Caller Characteristics of a Malaysian Cancer-Specific Information Hotline

Background: Despite the advancement of technology in information dissemination, patients and caregivers often cite difficulties in getting the right cancer information, care and psychosocial support. It is crucial to optimize the availability of cancer information to increase knowledge among the public and for better decision making by patients and their families. In line with these strategies, the National Cancer Society of Malaysia (NCSM) established a toll-free, Cancer Information Service Helpline (CIS) in 2016 to act as a tool for provision of cancer-related information and psychosocial support. Aim: This study aimed to analyze caller characteristics and trends of calls received by the CIS between January 1 to December 31, 2017. Methods: A cross sectional study was conducted on the CIS call logs for the ascertained study period. Descriptive analysis was carried out to determine characteristics of callers including i) socio-demographics; ii) geographical location; iii) caller's cancer disease status or relationship with cancer patient and iv) reason(s) for calling the helpline. ANOVA was used to determine possible associations between the different variables and reasons for calling the helpline. Results: A total of 1613 calls were received during the study period. Majority of the callers were female (72%) and almost half of the callers were healthcare professionals (43%). 36% of the calls were inquiries on availability of screening services and this was significantly associated with calls from healthcare professionals ( P = 0.04). Callers of Malay ethnicity ( P = 0.03) and newly diagnosed cancer patients ( P = 0.001) were significantly associated with calling to seek for financial help. Conclusion: While being used as a source of some aspects of information pertaining to cancer, the CIS's capabilities in providing psychosocial support is not being maximized as yet. These results provide insight that targeted promotional efforts to raise awareness about CIS's psychosocial support capabilities is required to further maximize its potential among Malaysian patients, families and the public at large.

Experience and Impact of a Locally-Based Peer, Volunteer Cancer Support Programme in Hospital Melaka, Melaka Malaysia

Background: Melaka is a small southern state in Peninsular Malaysia. On average, the state has an annual incidence of 200 odd breast cancer patients, largely treated out of its public, subsidized, single tertiary treatment center of Hospital Melaka. Hospital Melaka is an 800-bedded hospital with multiple specialties including surgery and radiology. Though the hospital does not have a dedicated oncology department, cancer treatment is carried out via phone consultations and visiting oncologists as well as a team of on-site nursing staff who are trained to initiate and monitor treatment. Feedback from Hospital Melaka staff highlighted that there was a drop-out rate of about 30% of patients from the treatment journey. Qualitative interviews with different stakeholders including patient revealed that the drop-out may be driven by factors such as: i) fear of surgery, ii) fear of chemotherapy, iii) fear of disfigurement, iv) loss of spouse v) emotional distress and shock; and vi) delay in waiting times for different levels of diagnostics and treatment. Aim: The aim of the initiative was to reduce the rate of patients who defaulted out from the cancer treatment journey via a three-pronged approach: a) improving understanding about cancer and treatment by patients and family members; b) integrating peer-support into the clinical treatment pathway at the hospital and reduction of waiting times; and c) maintaining a continuous interaction with the patient throughout the treatment journey. Methods: The inception and deployment of a locally-based peer, volunteer support program for breast cancer patients and families as part of the formal cancer treatment process in Hospital Melaka. Volunteers were consisted of a trained mix of cancer survivors, current and retired healthcare practitioners and provided information pertaining to treatment and care aspects of breast cancer as well as emotional support and follow-up of patients via phone or in person to ensure compliance to treatment. In this study, we engaged with various stakeholders including hospital management and clinicians. Then, support group's services were formalized into the care pathway for all patients with breast cancer; with both volunteers able to send and receive patient referrals. Results: Statistically significant reductions in patient delays in decision-making to seek treatment as well as a significant decrease of 12.5% in the number of defaulters. Conclusion: A support program built with support from all stakeholders and run by volunteers and embedded within the formal care process acts as a catalyst to enhance both service delivery as well as keeping patients engaged on the cancer care journey.

Is the Quality of Life in Breast Cancer Survivors the Same as Healthy Women? A Case Control Study Among Women in Klang Valley, Malaysia

Background: One of the positive outcomes of improvements in cancer care is the increasing number of people who survive the disease. Worldwide, the number of cancer survivors will continue to increase, with a threefold increase predicted from 25 million in 2008 to 75 million in 2030. Breast cancer survivors have the highest survival rates compared other types of cancer. Following a diagnosis of breast cancer, issues that women often worry about include the possibility of cancer recurrence, challenges with reacclimatizing to daily life posttreatment completion and numerous other emotional and physical challenges. It is unknown whether over time the coping skills of these survivors enable them to have a similar quality of life (QOL) as other normal women. This study aimed to assess and compare the quality of life (QOL) among breast cancer survivors and nonbreast cancer survivors in the Klang Valley, Malaysia. Methods: This case-control study used the European Organization for Research and Treatment of Cancer - Quality of Life Questionnaire (EORTC-QLQ) to ascertain QOL within breast cancer survivors and nonbreast cancer survivors. Simple random sampling was used to identify i) participants from the case arm -from four cancer-related NGOs in the Klang Valley; and ii) participants from the control arm - from women attending Kuala Lumpur Hospital. 176 number of participants were involved in this study with a 1:1 ratio. Result: There was no significant difference in quality of life (QOL) between breast cancer survivors and nonbreast cancer survivors in the Klang Valley, Malaysia. The longer the period of survival (5 years and above), the higher the QOL levels in breast cancer survivors. Conclusion: In conclusion, women with breast cancer especially those who had survived more than 5 years, had similar quality of life (QOL) levels as women who did not suffer from the disease. Women with breast cancer may have developed additional coping skills which could be taught to other patients living with cancer or even those with other chronic illnesses.

First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31  keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44}  cm^{2} for a 100  GeV/c^{2} WIMP mass (90% C.L.).

A Phase II Study of Pembrolizumab in EGFR-Mutant, PD-L1+, Tyrosine Kinase Inhibitor Naïve Patients With Advanced NSCLC

BACKGROUND

Despite the significant antitumor activity of pembrolizumab in NSCLC, clinical benefit has been less frequently observed in patients whose tumors harbor EGFR mutations compared to EGFR wild-type patients. Our single-center experience on the KEYNOTE-001 trial suggested that pembrolizumab-treated EGFR-mutant patients, who were tyrosine kinase inhibitor (TKI) naïve, had superior clinical outcomes to those previously treated with a TKI. As TKI naïve EGFR-mutants have generally been excluded from pembrolizumab studies, data to guide treatment decisions in this patient population is lacking, particularly in patients with programmed death ligand 1 (PD-L1) expression ≥50%.

METHODS

We conducted a phase II trial (NCT02879994) of pembrolizumab in TKI naive patients with EGFR mutation-positive, advanced NSCLC and PD-L1-positive (≥1%, 22C3 antibody) tumors. Pembrolizumab was administered 200 mg every 3 weeks. The primary endpoint was objective response rate. Secondary endpoints included safety of pembrolizumab, additional pembrolizumab efficacy endpoints, and efficacy and safety of an EGFR TKI after pembrolizumab.

RESULTS

Enrollment was ceased due to lack of efficacy after 11 of 25 planned patients were treated. Eighty-two percent of trial patients were treatment naïve, 64% had sensitizing EGFR mutations, and 73% had PD-L1 expression ≥50%. Only 1 patient had an objective response (9%), but repeat analysis of this patient's tumor definitively showed the original report of an EGFR mutation to be erroneous. Observed treatment-related adverse events were similar to prior experience with pembrolizumab, but two deaths within 6 months of enrollment, including one attributed to pneumonitis, were of concern.

CONCLUSIONS

Pembrolizumab's lack of efficacy in TKI naïve, PD-L1+, EGFR-mutant patients with advanced NSCLC, including those with PD-L1 expression ≥50%, suggests that it is not an appropriate therapeutic choice in this setting.

Xerostomia, salivary characteristics and gland volumes following intensity-modulated radiotherapy for nasopharyngeal carcinoma: a two-year follow up

BACKGROUND

To evaluate changes in xerostomia status, salivary characteristics and gland volumes 2 years following radiotherapy in nasopharyngeal carcinoma patients.

METHODS

Xerostomia scores, salivary flow rates, pH and buffering capacity were measured at pre-radiotherapy, mid-radiotherapy, 2 weeks, 3 months and 2 years post-radiotherapy. Salivary gland volumes and their correlation with radiation dose were also assessed.

RESULTS

Mean radiation dose to oral cavity, parotid and submandibular glands (SMG) was 44.5, 65.0 and 38.6 Gy respectively. Parotid and SMG volumes decreased 33% at 3 months post-radiotherapy; volumes at 2 years post-radiotherapy were 84% and 51% of pre-radiotherapy levels, respectively. Correlations were observed between parotid gland volume per cent reduction and its radiation dose and between resting salivary flow rate reduction and post-radiotherapy/pre-radiotherapy SMG volume ratio. Salivary flow rates and resting saliva pH remained significantly low at 2 years post-radiotherapy (both flow rates, P = 0.001; resting saliva pH, P = 0.005). Similarly, xerostomia scores remained significantly higher compared with pre-radiotherapy levels.

CONCLUSIONS

Submandibular gland volumetric shrinkage persisted 2 years after radiotherapy. Xerostomia scores remained significantly higher, and salivary flow rates and resting saliva pH remained significantly lower, suggesting that study participants were still at risk for hyposalivation-related oral diseases.

Bevacizumab improves survival in patients with synchronous colorectal liver metastases provided the primary tumor is resected first

BACKGROUND

Multimodal strategy including chemotherapy and hepatectomy is advocated for the management of colorectal liver metastases (CRLM). The aim of this study was to evaluate the impact of neoadjuvant Bevacizumab-based chemotherapy on survival in patients with resected stage IVA colorectal cancer and liver metastases.

METHODS

Data from 120 consecutive patients who received neoadjuvant chemotherapy and underwent curative-intent hepatectomy for synchronous CRLM were retrospectively reviewed. Overall survival (OS) was stratified according to administration of Bevacizumab before liver resection and surgical strategy, i.e., classical strategy (primary tumor resection first) versus reverse strategy (liver metastases resection first).

RESULTS

Patients who received Bevacizumab (n = 37; 30%) had a higher number of CRLM (p = 0.003) and underwent more often reverse strategy (p = 0.005), as compared to those who did not (n = 83; 70%). Bevacizumab was associated with an improved OS compared with conventional chemotherapy (p = 0.04). After stratifying by the surgical strategy, Bevacizumab was associated with improved OS in patients who had classical strategy (p = 0.03). In contrast, Bevacizumab had no impact on OS among patients who had liver metastases resection first (p = 0.89).

CONCLUSIONS

Neoadjuvant Bevacizumab-based chemotherapy was associated with improved OS in patients who underwent liver resection of synchronous CRLM, especially in those who underwent primary tumor resection first.

A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos

OBJECTIVES

To compare two molecular assays (rrs quantitative PCR (qPCR) versus a combined 16SrRNA and LipL32 qPCR) on different sample types for diagnosing leptospirosis in febrile patients presenting to Mahosot Hospital, Vientiane, Laos.

METHODS

Serum, buffy coat and urine samples were collected on admission, and follow-up serum ∼10 days later. Leptospira spp. culture and microscopic agglutination tests (MAT) were performed as reference standards. Bayesian latent class modelling was performed to estimate sensitivity and specificity of each diagnostic test.

RESULTS

In all, 787 patients were included in the analysis: 4/787 (0.5%) were Leptospira culture positive, 30/787 (3.8%) were MAT positive, 76/787 (9.7%) were rrs qPCR positive and 20/787 (2.5%) were 16SrRNA/LipL32 qPCR positive for pathogenic Leptospira spp. in at least one sample. Estimated sensitivity and specificity (with 95% CI) of 16SrRNA/LipL32 qPCR on serum (53.9% (33.3%-81.8%); 99.6% (99.2%-100%)), buffy coat (58.8% (34.4%-90.9%); 99.9% (99.6%-100%)) and urine samples (45.0% (27.0%-66.7%); 99.6% (99.3%-100%)) were comparable with those of rrs qPCR, except specificity of 16SrRNA/LipL32 qPCR on urine samples was significantly higher (99.6% (99.3%-100%) vs. 92.5% (92.3%-92.8%), p <0.001). Sensitivities of MAT (16% (95% CI 6.3%-29.4%)) and culture (25% (95% CI 13.3%-44.4%)) were low. Mean positive Cq values showed that buffy coat samples were more frequently inhibitory to qPCR than either serum or urine (p <0.001).

CONCLUSIONS

Serum and urine are better samples for qPCR than buffy coat, and 16SrRNA/LipL32 qPCR performs better than rrs qPCR on urine. Quantitative PCR on admission is a reliable rapid diagnostic tool, performing better than MAT or culture, with significant implications for clinical and epidemiological investigations of this global neglected disease.

Metastatic melanoma: prognostic factors and survival in patients with brain metastases

Brain metastases from malignant melanoma carry a poor prognosis. Novel systemic agents have improved overall survival (OS), but the value of whole-brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS) remains uncertain. The melanoma-specific graded prognostic assessment (msGPA) provides useful prognostic information, but the relevance to the modern-day population has not been validated. Since 2011, 53 patients received treatment for brain metastases from malignant melanoma at the Rosemere Cancer Centre medical oncology clinic. Data were collated on demographic factors and survival. Survival analyses were performed using Kaplan–Meier methods. Cox regression was used to identify prognostic factors on univariate and multivariate analysis. OS from the date of diagnosis of brain metastases was 4.83 months (range 0.27–30.4 months). On univariate analysis, BRAF, performance status and msGPA were significant prognostic indicators for OS (p = 0.0056, p = 0.0039 and p = 0.0001 respectively). msGPA remained significant on multivariate analysis (p = 0.0006). OS for BRAF-positive patients receiving targeted treatment (n = 22) was significantly better than for BRAF-negative patients (n = 26), with median survival times of 8.2 and 3.7 months respectively (p = 0.0039, HR 2.36). SRS combined with systemic agents (n = 16) produced an OS of 13.5 months. Patients receiving WBRT alone (n = 21) had a poor prognosis (2.2 months). The msGPA remains a valid prognostic indicator in the era of novel systemic treatments for melanoma. BRAF-positive patients receiving targeted agents during their treatment had favorable survival outcomes. WBRT alone should be use with caution in the active management of melanoma brain metastases.