Treatable traits can be identified in a severe asthma registry and predict future exacerbations

BACKGROUND AND OBJECTIVE

A new taxonomic and management approach, termed treatable traits, has been proposed for airway diseases including severe asthma. This study examined whether treatable traits could be identified using registry data and whether particular treatable traits were associated with future exacerbation risk.

METHODS

The Australasian Severe Asthma Web-Based Database (SAWD) enrolled 434 participants with severe asthma and a comparison group of 102 participants with non-severe asthma. Published treatable traits were mapped to registry data fields and their prevalence was described. Participants were characterized at baseline and every 6 months for 24 months.

RESULTS

In SAWD, 24 treatable traits were identified in three domains: pulmonary, extrapulmonary and behavioural/risk factors. Patients with severe asthma expressed more pulmonary and extrapulmonary treatable traits than non-severe asthma. Allergic sensitization, upper-airway disease, airflow limitation, eosinophilic inflammation and frequent exacerbations were common in severe asthma. Ten traits predicted exacerbation risk; among the strongest were being prone to exacerbations, depression, inhaler device polypharmacy, vocal cord dysfunction and obstructive sleep apnoea.

CONCLUSION

Treatable traits can be assessed using a severe asthma registry. In severe asthma, patients express more treatable traits than non-severe asthma. Traits may be associated with future asthma exacerbation risk demonstrating the clinical utility of assessing treatable traits.

Diagnosis of the cause of chronic dyspnoea in primary and tertiary care: characterizing diagnostic confidence

Background

Chronic dyspnoea (breathlessness) in adults is a common symptom, the exact cause of which may be difficult to diagnose on initial presentation. We characterised the diagnostic complexity of chronic dyspnoea in primary care and tertiary care.

Methods

This retrospective observational study screened consecutive referral letters of all adult patients referred to cardiology or respiratory clinics at a tertiary referral hospital, during May to June 2015. For patients referred due to chronic dyspnoea, data were analysed from the initial referral letter and subsequent specialist clinic letters for the 6-month time period after referral.

Results

Of 1,370 patient referrals, 122 patients (mean age 63 y, 55% female) were referred due to chronic dyspnoea. One hundred and five patients (86%) were referred from primary care and 17 (14%) from other hospital clinics. Sixty-one percent were referred with an evident diagnosis (referrer was confident of the initial diagnosis), whereas 39% had non-evident or unclear diagnoses. By 6 months after referral, a definitive final diagnosis had been determined by the specialist clinics in 62% of patients. The majority of patients had been referred appropriately to a cardiology or respiratory clinic, based on the final diagnosis. However, only 26% of diagnoses were fully concordant between the initial referrer diagnosis and the final specialist clinic diagnosis, with 26% being partially concordant and 48% non-concordant. Diagnostic certainty of the referrer was associated with concordance of diagnosis between the referrer and specialist clinic (P<0.001).

Conclusions

In adult patients referred due to chronic dyspnoea to hospital specialist clinics, there is considerable diagnostic uncertainty about its aetiology, for both referring doctors and specialist clinics. These results demonstrate the current difficulty in diagnosing the cause of chronic dyspnoea in adults, and highlight the need for evidence-based diagnostic pathways.

Gefitinib for advanced non-small cell lung cancer

BACKGROUND

The role of gefitinib for the treatment of advanced non-small cell lung cancer (NSCLC) is evolving. We undertook a systematic review to evaluate the available evidence from all randomised trials.

OBJECTIVES

To determine the effectiveness and safety of gefitinib as first-line, second-line or maintenance treatment for advanced NSCLC.

SEARCH METHODS

We performed searches in CENTRAL, MEDLINE and Embase from inception to 17 February 2017. We handsearched relevant conference proceedings, clinical trial registries and references lists of retrieved articles.

SELECTION CRITERIA

We included trials assessing gefitinib, alone or in combination with other treatment, compared to placebo or other treatments in the first- or successive-line treatment of patients with NSCLC, excluding compassionate use.

DATA COLLECTION AND ANALYSIS

We used the standard Cochrane methodology. Two authors independently assessed the search results to select those with sound methodological quality. We carried out all analyses on an intention-to-treat basis. We recorded the following outcome data: overall survival, progression-free survival, toxicity, tumour response and quality of life. We also collected data for the following subgroups: Asian ethnicity and positive epidermal growth factor receptor (EGFR) mutation.

MAIN RESULTS

We included 35 eligible randomised controlled trials (RCTs), which examined 12,089 patients.General populationGefitinib did not statistically improve overall survival when compared with placebo or chemotherapy in either first- or second-line settings. Second-line gefitinib prolonged time to treatment failure (TTF) (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.75 to 0.90, P < 0.0001) when compared with placebo. Maintenance gefitinib improved progression-free survival (HR 0.70, 95% CI 0.53 to 0.91, P = 0.007) after first-line therapy.Studies in patients of Asian ethnicity or that conducted subgroup analysesSecond-line gefitinib prolonged overall survival over placebo (HR 0.66, 95% CI 0.48 to 0.91, P = 0.01). In the first-line setting, progression-free survival was improved with gefitinib over chemotherapy alone (HR 0.65, 95% CI 0.43 to 0.98, P = 0.04, moderate quality of evidence). Gefitinib given in combination with a chemotherapy regimen improved progression-free survival versus either gefitinib alone or chemotherapy alone (HR 0.69, 95% CI 0.49 to 0.96, P = 0.03; HR 0.69, 95% CI 0.62 to 0.77, P < 0.00001, respectively). In the second-line setting, progression-free survival was superior in patients given gefitinib over placebo or chemotherapy (HR 0.69, 95% CI 0.52 to 0.91, P = 0.009; HR 0.71, 95% CI 0.57 to 0.88, P = 0.002; moderate quality of evidence, respectively). Combining gefitinib with chemotherapy in the second-line setting was superior to gefitinib alone (HR 0.65, 95% CI 0.43 to 0.97, P = 0.04). As maintenance therapy, gefitinib improved progression-free survival when compared with placebo (HR 0.42, 95% CI 0.33 to 0.54, P < 0.00001).Patients with EGFR mutation-positive tumoursStudies in patients with EGFR mutation-positive tumours showed an improvement in progression-free survival in favour of gefitinib over first-line and second-line chemotherapy (HR 0.47, 95% CI 0.36 to 0.61, P < 0.00001; HR 0.24, 95% CI 0.12 to 0.47, P < 0.0001, respectively). Gefitinib as maintenance therapy following chemotherapy improved overall and progression-free survival (HR 0.39, 95% CI 0.15 to 0.98, P = 0.05; HR 0.17, 95% CI 0.07 to 0.41, P < 0.0001, respectively) in one phase III study when compared to placebo.Toxicities from gefitinib included skin rash, diarrhoea and liver transaminase derangements. Toxicities from chemotherapy included anaemia, neutropenia and neurotoxicity.In terms of quality of life, gefitinib improved Functional Assessment of Cancer Therapy-Lung (FACT-L) (standardised mean difference (SMD) 10.50, 95% CI 9.55 to 11.45, P < 0.000001), lung cancer subscale (SMD 3.63, 95% CI 3.08 to 4.19, P < 0.00001) and Trial Outcome Index (SMD 9.87, 95% CI 1.26 to 18.48, P < 0.00001) scores when compared with chemotherapy.

AUTHORS' CONCLUSIONS

This systematic review shows that gefitinib, when compared with standard first- or second-line chemotherapy or maintenance therapy, probably has a beneficial effect on progression-free survival and quality of life in selected patient populations, particularly those with tumours bearing sensitising EGFR mutations.Patients with EGFR mutations lived longer when given maintenance gefitinib than those given placebo.One study conducted subgroup analysis and showed that gefitinib improved overall survival over placebo in the second-line setting in patients of Asian ethnicity. All other studies did not detect any benefit on overall survival. The data analysed in this review were very heterogenous. We were limited in the amount of data that could be pooled, largely due to variations in study design. The risk of bias in most studies was moderate, with some studies not adequately addressing potential selection, attrition and reporting bias. This heterogeneity may have an impact on the applicability of the resultsCombining gefitinib with chemotherapy appears to be superior in improving progression-free survival to either gefitinib or chemotherapy alone, however further data and phase III studies in these settings are required.Gefitinib has a favourable toxicity profile when compared with current chemotherapy regimens. Although there is no improvement in overall survival, gefitinib compares favourably with cytotoxic chemotherapy in patients with EGFR mutations with a prolongation of progression-free survival and a lesser side effect profile.

Ultrafine particle transport and deposition in a large scale 17-generation lung model

To understand how to assess optimally the risks of inhaled particles on respiratory health, it is necessary to comprehend the uptake of ultrafine particulate matter by inhalation during the complex transport process through a non-dichotomously bifurcating network of conduit airways. It is evident that the highly toxic ultrafine particles damage the respiratory epithelium in the terminal bronchioles. The wide range of in silico available and the limited realistic model for the extrathoracic region of the lung have improved understanding of the ultrafine particle transport and deposition (TD) in the upper airways. However, comprehensive ultrafine particle TD data for the real and entire lung model are still unavailable in the literature. Therefore, this study is aimed to provide an understanding of the ultrafine particle TD in the terminal bronchioles for the development of future therapeutics. The Euler-Lagrange (E-L) approach and ANSYS fluent (17.2) solver were used to investigate ultrafine particle TD. The physical conditions of sleeping, resting, and light activity were considered in this modelling study. A comprehensive pressure-drop along five selected path lines in different lobes was calculated. The non-linear behaviour of pressure-drops is observed, which could aid the health risk assessment system for patients with respiratory diseases. Numerical results also showed that ultrafine particle-deposition efficiency (DE) in different lobes is different for various physical activities. Moreover, the numerical results showed hot spots in various locations among the different lobes for different flow rates, which could be helpful for targeted therapeutical aerosol transport to terminal bronchioles and the alveolar region.

Low tumour cell content in a lung tumour bank: implications for molecular characterisation

Lung cancer encompasses multiple malignant epithelial tumour types, each with specific targetable, potentially actionable mutations, such that precision management mandates accurate tumour typing. Molecular characterisation studies require high tumour cell content and low necrosis content, yet lung cancers are frequently a heterogeneous mixture of tumour and stromal cells. We hypothesised that there may be systematic differences in tumour cell content according to histological subtype, and that this may have implications for tumour banks as a resource for comprehensive molecular characterisation studies in lung cancer. To investigate this, we estimated tumour cell and necrosis content of 4267 samples resected from 752 primary lung tumour specimens contributed to a lung tissue bank. We found that banked lung cancer samples had low tumour cell content (33%) generally, although it was higher in carcinoids (77.5%) than other lung cancer subtypes. Tumour cells comprise a variable and often small component of banked resected tumour samples, and are accompanied by stromal reaction, inflammation, fibrosis, and normal structures. This has implications for the adequacy of unselected tumour bank samples for diagnostic and molecular investigations, and further research is needed to determine whether tumour cell content has a significant impact on analytical results in studies using tissue from tumour bank resources.

Effect of azithromycin on asthma exacerbations and quality of life in adults with persistent uncontrolled asthma (AMAZES): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Exacerbations of asthma cause a substantial global illness burden. Adults with uncontrolled persistent asthma despite maintenance treatment require additional therapy. Since macrolide antibiotics can be used to treat persistent asthma, we aimed to assess the efficacy and safety of oral azithromycin as add-on therapy in patients with uncontrolled persistent asthma on medium-to-high dose inhaled corticosteroids plus a long-acting bronchodilator.

METHODS

We did a randomised, double-blind, placebo controlled parallel group trial to determine whether oral azithromycin decreases the frequency of asthma exacerbations in adults (≥18 years) with symptomatic asthma despite current use of inhaled corticosteroid and long-acting bronchodilator, and who had no hearing impairment or abnormal prolongation of the corrected QT interval. Patients were randomly assigned (1:1) to receive azithromycin 500 mg or placebo three times per week for 48 weeks. Patients were centrally allocated using concealed random allocation from a computer-generated random numbers table with permuted blocks of 4 or 6 and stratification for centre and past smoking. Primary efficacy endpoints were the rate of total (severe and moderate) asthma exacerbations over 48 weeks and asthma quality of life. Data were analysed on an intention-to-treat basis. The trial is registered at the Australian and New Zealand Clinical Trials Registry (ANZCTR), number 12609000197235.

FINDINGS

Between June 12, 2009, and Jan 31, 2015, 420 patients were randomly assigned (213 in the azithromycin group and 207 in the placebo group). Azithromycin reduced asthma exacerbations (1·07 per patient-year [95% CI 0·85-1·29]) compared with placebo (1·86 per patient-year [1·54-2·18]; incidence rate ratio [IRR] 0·59 [95% CI 0·47-0·74]; p<0·0001). The proportion of patients experiencing at least one asthma exacerbation was reduced by azithromycin treatment (127 [61%] patients in the placebo group vs 94 [44%] patients in the azithromycin group, p<0·0001). Azithromycin significantly improved asthma-related quality of life (adjusted mean difference, 0·36 [95% CI 0·21-0·52]; p=0·001). Diarrhoea was more common in azithromycin-treated patients (72 [34%] vs 39 [19%]; p=0·001).

INTERPRETATION

Adults with persistent symptomatic asthma experience fewer asthma exacerbations and improved quality of life when treated with oral azithromycin for 48 weeks. Azithromycin might be a useful add-on therapy in persistent asthma.

FUNDING

National Health and Medical Research Council of Australia, John Hunter Hospital Charitable Trust.

A survey of lung cancer in rural and remote Aboriginal and Torres Strait Islander communities in Queensland: health views that impact on early diagnosis and treatment

BACKGROUND

Lung cancer incidence, mortality and hospitalisation rates are higher for Indigenous Australians compared with non-Indigenous Australians and increase again when living in more remote areas. If Indigenous Australians are made more aware of lung cancer through better access to health services and programmes, lung cancer outcomes might improve.

AIM

We aimed to survey the level of lung cancer awareness in rural and remote Aboriginal and Torres Strait Islander communities and discover perceived barriers to timely diagnosis and treatment of lung cancer.

METHODS

Interviews were conducted in three discrete outer regional and remote Aboriginal communities and one urban setting in Queensland. Participants included Aboriginal and Torres Strait Islander peoples from three target population groups: patients referred for medical treatment with symptoms suspicious of lung cancer or confirmed lung cancer; Indigenous health workers; community members aged 18 years and over. Participants gave written, informed consent.

RESULTS

Of 51 community members and 14 Indigenous health workers, 32 reflected they knew very little about lung cancer, 60 cited smoking as the cause of lung cancer and 54 recognised warning symptoms as a prompt to seek healthcare. Indigenous health workers were not able to describe a healthcare pathway that would apply to a patient with suspected lung cancer.

CONCLUSION

The two main barriers identified as impacting on quality healthcare were communication and follow-up processes. These could be addressed by service improvement activities.

Utility of thrombophilia testing in patients with venous thrombo-embolism

BACKGROUND

Clinical practice of thrombophilia testing those with venous thrombo-embolism (VTE) in public hospitals may not be consistent with the international guidelines. This study aims to assess whether practice of thrombophilia testing in two public hospitals are consistent with international guidelines, and to assess whether certain groups of patients were more likely to benefit from testing.

METHODS

A retrospective audit on patients who presented to two Queensland public hospitals from August 2011 to September 2012 with VTE. Data were collected on demographics, yield of the test, and whether the result of the test changed the duration of anticoagulation. Group analysis was performed to identify patients who were more likely to yield positive results.

RESULTS

Of the 152 patients, 49% were tested for thrombophilia, of whom 31% returned a positive result. 38% of patients with provoked VTE were tested for thrombophilia, inconsistent with guideline recommendations. In 1.2% of cases there were documented changes to duration of anticoagulation with positive results. The rates of positive results were 45% in unprovoked VTE cases compared with 29% in provoked VTE cases (P=0.054). The rates of positive results were 52% in recurrent VTE cases compared with 27% in those cases with first episode of VTE (P=0.007).

CONCLUSIONS

The practice of thrombophilia testing in public hospitals was frequently inconsistent with guidelines, and did not significantly influence clinical decisions. There was higher yield of testing in patients with recurrent episodes of VTE and possibly in patients with unprovoked VTE.

Blood cytotoxic/inflammatory mediators in non-eosinophilic asthma

BACKGROUND

Non-eosinophilic asthma (NEA) is a distinct, often corticosteroid-resistant inflammatory asthma phenotype. NK and NKT-like cells are effector lymphocytes that we have shown, like CD28null T cells, to be relatively resistant to steroids and major sources of pro-inflammatory/cytotoxic mediators. We hypothesized that these cells and mediators would be increased in peripheral blood in NEA.

METHODS

Adults with severe asthma and variable airflow obstruction, poorly controlled despite maintenance therapy with inhaled glucocorticosteroids and long-acting bronchodilators, were recruited. Blood was assessed in those with eosinophilic asthma (n = 12), NEA (n = 25) and healthy non-smoking controls (n = 30). We applied flow cytometry to measure T, CD28null, NK and NKT-like cells and their expression of granzyme B, perforin, and killer inhibitory/activating receptors CD94(Kp43), CD158b and CD107A. Intracellular pro-inflammatory cytokine production (IFN-γ and TNF-α) was assessed in 18 controls and 10 patients with asthma/group.

RESULTS

In NEA, there was increased expression of granzyme B by CD8+ T cells vs.

CONTROLS

There was increased expression of granzyme B and CD158 and decreased CD94 on NK cells, vs. healthy controls and those with eosinophilic asthma. IFN-γ production by NK cells and TNF-α production by NKT-like cells in NEA were significantly increased vs.

CONTROLS

In both eosinophilic and NEA phenotypes, there were significant increases in CD4+28null T cells (72% and 81% increases, respectively, vs. controls) and their expression of pro-inflammatory cytokines. Significant correlations were noted between blood CD4+28null T cells and neutrophil numbers in induced sputum, and between corticosteroid dose and blood NKT-like cells, and their production of granzyme B and TNF-α and NK IFN-γ.

CONCLUSION AND CLINICAL RELEVANCE

In poorly controlled asthma, altered expression of cytotoxic/pro-inflammatory mediators can be seen on a variety of lymphocyte subsets in the peripheral blood; these changes are most apparent in NEA. Whether this pattern of expression is a marker of treatment responsiveness and future risk of exacerbations remains to be determined.

Periostin levels and eosinophilic inflammation in poorly-controlled asthma

BACKGROUND

Periostin levels are associated with airway eosinophilia and are suppressed by corticosteroid treatment in asthma. This study sought to determine the relationship between serum and sputum periostin, airway inflammatory phenotype and asthma control.

METHODS

Adults with poorly-controlled asthma (n = 83) underwent a clinical assessment, sputum induction and blood sampling. Dispersed sputum was used for a differential cell count and periostin assessment (ELISA). Serum periostin was determined by the Elecsys® immunoassay.

RESULTS

Periostin levels were significantly higher in serum (median (IQR) of 51.6 (41.8, 62.6) ng/mL) than in sputum (1.1 (0.5, 2.0) ng/mL) (p < 0.001). Serum and sputum periostin were significantly higher in patients with eosinophilic asthma (n = 37) compared with non-eosinophilic asthma. Both serum and sputum periostin levels were significantly associated with proportion of sputum eosinophils (r = 0.422, p < 0.001 and r = 0.364, p = 0.005 respectively) but were not associated with asthma control. In receiver operator characteristic curve analysis, the area under the curve (AUC) for serum periostin (n = 83) was 0.679, p = 0.007. Peripheral blood eosinophils assessed in 67 matched samples, had a numerically greater AUC of 0.820 compared with serum periostin, p = 0.086 for the detection of eosinophilic asthma.

CONCLUSION

In poorly-controlled asthma, sputum and serum periostin levels are significantly related to sputum eosinophil proportions while their ability to predict the presence of eosinophilic asthma is modest.

Acute exacerbation of COPD

The literature of acute exacerbation of chronic obstructive pulmonary disease (COPD) is fast expanding. This review focuses on several aspects of acute exacerbation of COPD (AECOPD) including epidemiology, diagnosis and management. COPD poses a major health and economic burden in the Asia-Pacific region, as it does worldwide. Triggering factors of AECOPD include infectious (bacteria and viruses) and environmental (air pollution and meteorological effect) factors. Disruption in the dynamic balance between the 'pathogens' (viral and bacterial) and the normal bacterial communities that constitute the lung microbiome likely contributes to the risk of exacerbations. The diagnostic approach to AECOPD varies based on the clinical setting and severity of the exacerbation. After history and examination, a number of investigations may be useful, including oximetry, sputum culture, chest X-ray and blood tests for inflammatory markers. Arterial blood gases should be considered in severe exacerbations, to characterize respiratory failure. Depending on the severity, the acute management of AECOPD involves use of bronchodilators, steroids, antibiotics, oxygen and noninvasive ventilation. Hospitalization may be required, for severe exacerbations. Nonpharmacological interventions including disease-specific self-management, pulmonary rehabilitation, early medical follow-up, home visits by respiratory health workers, integrated programmes and telehealth-assisted hospital at home have been studied during hospitalization and shortly after discharge in patients who have had a recent AECOPD. Pharmacological approaches to reducing risk of future exacerbations include long-acting bronchodilators, inhaled steroids, mucolytics, vaccinations and long-term macrolides. Further studies are needed to assess the cost-effectiveness of these interventions in preventing COPD exacerbations.

Screen-detected subsolid pulmonary nodules: long-term follow-up and application of the PanCan lung cancer risk prediction model

OBJECTIVE

To report the long-term follow-up of subsolid nodules (SSNs) detected in participants of a prospective low-dose CT lung cancer screening cohort, and to investigate the utility of the PanCan model in stratifying risk in baseline SSNs.

METHODS

Participants underwent a baseline scan, two annual incidence scans and further follow-up scans for the detected nodules. All SSNs underwent a minimum of 2 years of follow-up (unless resolved or resected). Risk of malignancy was estimated using the PanCan model; discrimination [area under the receiver-operating characteristic curve (AUC)] and calibration (Hosmer-Lemeshow goodness-of-fit test) were assessed. The Mann-Whitney U-Wilcoxon test was used to compare estimated risk between groups.

RESULTS

70 SSNs were detected in 41 (16.0%) out of 256 total participants. Median follow-up period was 25.5 months (range 2.0-74.0 months). 29 (41.4%) SSNs were transient. Five (7.1%) SSNs were resected, all found to be Stage I lung adenocarcinoma, including one SSN stable in size for 3.0 years before growth was detected. The PanCan model had good discrimination for the 52 baseline SSNs (AUC = 0.89; 95% confidence interval 0.76-1); the Hosmer-Lemeshow goodness-of-fit test was non-significant (p = 0.27). Estimated risk was significantly higher in the baseline SSNs found to be cancer vs those not found to be cancer after 2-6 years of follow-up (p < 0.01).

CONCLUSION

Our findings support a long-term follow-up approach for screen-detected SSNs for 3 years or longer. The PanCan model appeared discriminatory and well calibrated in this cohort.

ADVANCES IN KNOWLEDGE

The PanCan model may have utility in identifying low-risk SSNs which could be followed with less frequent CT scans.

Brief Tailored Smoking Cessation Counseling in a Lung Cancer Screening Population is Feasible: A Pilot Randomized Controlled Trial

INTRODUCTION

Maximizing smoking abstinence in lung cancer screening participants is important to reduce individual risk of disease and improve screening cost-effectiveness; however, the optimal strategy remains undefined. We hypothesized that a single session of tailored face-to-face counseling on the day of screening CT scan, coupled with audio and printed cessation information would be feasible to deliver in a CT screening trial.

METHODS

We randomized volunteer smokers in the Queensland Lung Cancer Screening Study to intervention (counseling session, audio quit materials, printed quit materials, Quitline contact details) or control group (printed quit materials, Quitline contact details). Participants self-reported point prevalence quit rates at 1 year.

RESULTS

Fifty-five smokers were enrolled; 28 randomized to intervention and 27 controls. Median cigarette consumption was 25/day; 54/55 smoked at least 15 cigarettes per day. Median smoking duration was 46 years. Median Fagerström dependence score was 6. In total 58% did not report any quit attempt in the prior 12 months. Mean duration of counseling was 26.5 minutes. After 1 year, four participants (14.3%) in the intervention group and five participants (18.5%) in the control group had quit (P = .74). Combined annual point prevalence quit rate was 16.4%.

CONCLUSIONS

Although feasible to deliver a single session of tailored counseling on the day of screening this intervention had no discernible impact on cessation over and above printed materials and Quitline access. As participants exhibited hardcore smoking characteristics, more intensive strategies, in larger cohorts, should be explored.

IMPLICATIONS

The optimal smoking cessation strategy within a lung cancer screening program is not known. This study demonstrates that a single session of counseling can be feasibly delivered on the day of screening but may not have been intensive enough for long-term, hard-core smokers.

Abstract 24: Intratumoral genomic heterogeneity of primary pulmonary adenocarcinoma in never smokers

Aim: Intratumoral genomic heterogeneity challenges personalized lung cancer care, especially where it relies upon small diagnostic samples. To explore genomic representation provided by tumor subsampling, we performed whole genome sequencing (WGS) of multiple regions of individual primary pulmonary adenocarcinomas (LUAC).

Methods: An observational study was performed on three cases of never-smoking LUAC resected with curative intent. Post-diagnostic residual fresh tumor was procured with informed consent, along with constitutional samples from normal lung or blood. Selection criteria included: histologically confirmed LUAC; never-smoker [defined as fewer than 100 cigarettes consumed in a lifetime]; and no prior malignancy, cytotoxic therapy or thoracic radiotherapy.

Tissue samples were procured by an anatomical pathologist and research scientist and snap frozen within 60 minutes of devascularization, then stored at -80 degrees celsius. Nine macrodissected subsamples met quality criteria of &gt;40% tumor cellularity and &lt;20% necrosis (Case 1, 4 regions; Case 2, 3 regions; Case 3, 2 regions) as assessed visually by 2 anatomical pathologists. High molecular weight DNA was extracted from tissue using Qiagen AllPrep DNA/RNA Mini Kit and from blood using Qiagen Blood Maxi Kit.

WGS was performed on paired end libraries using Illumina's HiSeq 2000 platform to 80x (tumor), 40x (normal lung) and 30x (blood) coverage. Reads were aligned to GRCh37 with BWA-MEM. Duplicates were removed using Picard and local INDEL realignment and base quality recalibration were performed with GATK. Single nucleotide variants (SNVs) were called by MuTect, Varscan, Strelka and SomaticSniper. Variants were considered ‘high priority’ if predicted by SNPEff to have ‘moderate’ or ‘high’ functional significance. Structural variants were detected from WGS data using Breakdancer and Pindel. Sample genotyping was performed using Illumina's HumanOmni2.5-8 array and used to call copy number variations (CNVs) using the Genome Alteration Print tool.

Results: All cases were Caucasian females. Case 1 consisted of a 37 year old with a well to moderately differentiated pathological stage IV (AJCC 7th Edition; T4 N1 M1a) tumor 75mm in maximal dimension for which DNA from 4 tumor regions and whole blood was available. Case 2 was an 80 year old with a 24mm, acinar predominant, moderately differentiated pathological stage 1A (T1b N0 M0) tumor for which DNA from 3 tumor regions and whole blood was available. Case 3 was an 82 year old with a 35mm, acinar predominant, pathological stage 1B (T2a N0 M0) tumor for which DNA from 2 tumor regions and non-tumor lung was available. Mean tumor cellularity (and mean sequencing coverage achieved) for regions 1, 2, 3 and 4 for case 1 were 50% (98x), 50% (100x), 73% (99x) and 58% (134x), respectively. Similarly, for regions 1, 2 and 3 of case 2, mean cellularity (and coverage) was 45% (93x), 45% (114x) and 40% (93x), respectively. Case 3 demonstrated 45% (107x) and 55% (97x) mean cellularity (and coverage) for regions 1 and 2, respectively. Less than 10% necrosis was observed in all tumor regions.

Of 10275 SNVs detected in case 1, 3198 (3198/10275, 31%) were found in all 4 subsamples. 6911/15689 (44%) and 5595/9528 (59%) were shared among all subsamples in cases 2 and 3, respectively. The numbers of SNVs unique to each region relative to total SNVs observed for each region in case were: 869/5999 (14%), 1129/6437 (18%), 914/6969 (13%) and 517/5936 (9%). Similarly, the numbers of unique SNVs as a proportion of total SNVs for each region in case 2 were 1148/9835 (12%), 2556/11404 (22%) and 2632/10714 (25%); and for case 3 were 2293/7888 (29%) and 1640/7235 (23%).

In case 1, 7 of 303 (2%) high priority variants were detected in all regions. Similarly, 44/303 (15%) and 29/302 (10%) high priority variants were detected in all tumor regions for case 2 and 3, respectively.

Conclusion: Significant intratumoral heterogeneity was observed. These findings have significant implications not only for diagnostic testing of lung cancer but also for clinical trial design. Prospective clinical trials incorporating assessment of both geographic and temporal intratumoral heterogeneity will help explore the implications of this phenomenon on patient treatment.

Acknowledgements: We acknowledge the patients, nurses, and staff of The Prince Charles Hospital for their contributions to this project.

Funding: MD supported by Cancer Council Queensland and NHMRC PhD Scholarships. Supported by funding from NHMRC, Cancer Australia, TPCH Foundation, Queensland Health, Cancer Council Queensland.

Citation Format: Marissa G. Daniels, Lutz Krause, Jonathan J. Ellis, Ian A. Yang, Rayleen V. Bowman, Vandana Relan, Kelly Chee, Felicia Goh, Brielle Parris, Leanne Morrison, Maria Martins, Linda Passmore, Elizabeth McCaul, Deborah Courtney, Edwina Duhig, Morgan Windsor, Rishendran Naidoo, Kwun M. Fong. Intratumoral genomic heterogeneity of primary pulmonary adenocarcinoma in never smokers. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Integrating Clinical Genomics and Cancer Therapy; Jun 13-16, 2015; Salt Lake City, UT. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(1_Suppl):Abstract nr 24.

Reduced Antiviral Interferon Production in Poorly Controlled Asthma Is Associated With Neutrophilic Inflammation and High-Dose Inhaled Corticosteroids

BACKGROUND

Asthma is a heterogeneous chronic inflammatory disease in which host defense against respiratory viruses such as human rhinovirus (HRV) may be abnormal. This is a matter of some controversy, with some investigators reporting reduced type I interferon (IFN) synthesis and others suggesting that type I IFN synthesis is relatively normal in asthma.

OBJECTIVE

The objective of this study was to examine the responsiveness of circulating mononuclear cells to HRV in a large cohort of participants with poorly controlled asthma and determine whether IFN-α and IFN-β synthesis varies across different inflammatory phenotypes.

METHODS

Eligible adults with asthma (n = 86) underwent clinical assessment, sputum induction, and blood sampling. Asthma inflammatory subtypes were defined by sputum cell count, and supernatant assessed for IL-1β. Peripheral blood mononuclear cells (PBMCs) were exposed to HRV serotype 1b, and IFN-α and IFN-β release was measured by enzyme-linked immunosorbent assay.

RESULTS

Participants (mean age, 59 years; atopy, 76%) had suboptimal asthma control (mean asthma control questionnaire 6, 1.7). In those with neutrophilic asthma (n = 12), HRV1b-stimulated PBMCs produced significantly less IFN-α than PBMCs from participants with eosinophilic (n = 35) and paucigranulocytic asthma (n = 35). Sputum neutrophil proportion and the dose of inhaled corticosteroids were independent predictors of reduced IFN-α production after HRV1b exposure.

CONCLUSIONS

Antiviral type I IFN production is impaired in those with neutrophilic airway inflammation and in those prescribed high doses of inhaled corticosteroids. Our study is an important step toward identifying those with poorly controlled asthma who might respond best to inhaled IFN therapy during exacerbations.

Airway dysbiosis: Haemophilus influenzae and Tropheryma in poorly controlled asthma

Asthma is a chronic inflammatory disorder of the airways where bacteria may act as protagonists of chronic inflammation. Little is known about the relation of airway inflammation to the presence of specific bacterial taxa. We sought to describe the sputum microbiome in adults with poorly controlled asthma.DNA was extracted from induced sputum and microbial communities were profiled using 16S rRNA pyrosequencing. Bacterial species were characterised, and the relationship between microbial populations, asthma inflammatory subtypes and other covariates was explored. Real-time PCR was used to identify Tropheryma whipplei and Haemophilus influenzae in sputum.Adults with neutrophilic asthma had reduced bacterial diversity and species richness. Tropheryma was identified and confirmed with real-time PCR in 12 (40%) participants. Haemophilus occurred most often in a group of younger atopic males with an increased proportion of neutrophils. PCR confirmed the presence of H. influenzae in 35 (76%) participants with poorly controlled asthma.There are phenotype-specific alterations to the airway microbiome in asthma. Reduced bacterial diversity combined with a high prevalence of H. influenzae was observed in neutrophilic asthma, whereas eosinophilic asthma had abundant T. whipplei.