Safety of curative-intent lung cancer surgery in older patients (octogenarians): A contemporary multicentre cohort study

INTRODUCTION

Despite octogenarians representing an ever-increasing proportion of patients with lung cancer, there is a paucity of evidence describing outcomes after lung resection for these patients. We aimed to evaluate short and mid-term outcomes for octogenarians after lung resection.

MATERIALS AND METHODS

A total of 5,470 consecutive patients undergoing lung resection for primary lung cancer from 2012-2019 in two UK centres were included. Primary outcomes were perioperative, 90-day, and one-year mortality in the octogenarian vs. non-octogenarian cohort. Appropriate statistical tests were used to compare outcomes between octogenarian and non-octogenarian patients. Secondary outcomes were post-operative complications and to validate the performance of the Thoracoscore model in the octogenarian cohort.

RESULTS

Overall, 9.4% (n=513) of patients were aged ≥80. The rates of 90-day mortality, one-year mortality, and post-operative atrial fibrillation were significantly higher for octogenarians. The one-year mortality rate for octogenarians fell significantly over time (2012-2015: 16.5% vs 2016-2019: 10.2%, p=0.034). Subgroup analysis (2016-2019 only) demonstrated no significant difference in peri-operative, 90-day, or one-year mortality between octogenarian and non-octogenarian patients. Validation of the Thoracoscore model demonstrated modest discrimination and acceptable calibration.

DISCUSSION

Mortality for octogenarians fell significantly over time in this study. Indeed, when confined to the most recent time period, comparable rates of both 90-day and one-year mortality for octogenarian and non-octogenarian patients were seen. Whilst preventative strategies to reduce the incidence of post-operative atrial fibrillation in octogenarians should be considered, these findings demonstrate that following appropriate patient selection, octogenarians can safely undergo lung resection for lung cancer.

The detection, assessment and clinical evolution of interstitial lung abnormalities identified through lung cancer screening

Introduction

Interstitial lung abnormalities (ILAs) are common incidental findings in lung cancer screening however their clinical evolution and longer-term outcomes are less clear. The aim of this cohort study was to report five-year outcomes of individuals with ILA identified through a lung cancer screening programme. In addition, we compared patient reported outcome measures (PROMs) in patients with screen-detected ILA to newly diagnosed interstitial lung disease (ILD) to assess symptoms and health-related quality of life (HRQOL).

Methods

Individuals with screen-detected ILA were identified and five-year outcomes, including ILD diagnoses, progression-free survival and mortality, were recorded. Risk factors associated with ILD diagnosis were assessed using logistic regression and survival using Cox proportional hazard analysis. PROMs were compared between a subset of patients with ILA and a group of ILD patients.

Results

1,384 individuals underwent baseline low-dose computed tomography (LDCT) screening with 54 (3.9%) identified as having ILA. 22 (40.7%) were subsequently diagnosed with ILD. 14 individuals (25.9%) died, and 28 (53.8%) suffered disease progression within five years. Fibrotic ILA was an independent risk factor for ILD diagnosis, mortality, and reduced progression-free survival. Patients with ILA had lower symptom burden and better HRQOL in comparison to the ILD group. Breathlessness visual analogue score (VAS) was associated with mortality on multivariate analysis.

Conclusions

Fibrotic ILA was a significant risk factor for adverse outcomes including subsequent ILD diagnosis. Whilst screen-detected ILA patients were less symptomatic, breathlessness VAS was associated with adverse outcomes. These results could inform risk stratification in ILA.

Breath biopsy early detection of lung cancer using an EVOC probe targeting tumor-specific extracellular β-glucuronidase

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Background: Lung cancer is a leading cause of mortality with 5-year survival less than 20%, largely a result of many cases being diagnosed late. Early detection can increase cancer survival up to 13-fold underscoring the need for effective screening. Targeted Low dose computed tomography (LDCT) has been shown to be effective but its impact to date has been limited due to slow adoption and variable uptake in high-risk populations. Breath analysis represents a non-invasive screening approach either alone or alongside LDCT. Numerous studies have investigated potential endogenous breath biomarkers of lung cancer. Many have produced promising results but to date, no validated biomarkers with clear connections to cancer metabolism have been revealed. We have explored an alternative, probe-based approach based around Exogenous Volatile Organic Compound Probes (EVOC Probes). The probes target tumour associated extracellular b-glucuronidase, a glycosidase enzyme that normally resides within lysosomes. Methods: We use a hydrophilic non cell permeable substrate probe D5-ethyl-βD-glucuronide (D5-EtGlu) that upon hydrolysis by the target enzyme releases D5-ethanol, a unique volatile reporter molecule detectable on breath. This provides a readout of tumour associated enzyme activity using breath analysis. Results: Administering D5-EtGlu to mice resulted in tumour specific release of D5-ethanol, enabling discrimination between healthy and tumour bearing animals. Increased expression of b-glucuronidase in lung cancer tissue and the tumour microenvironment was confirmed with immunohistochemistry (IHC) in clinical samples. A phase 1a clinical trial administered D5-EtGlu to healthy individuals in a single ascending dose study to establish safety and background D5-ethanol levels in healthy individuals. This resulted in no adverse events and low/no D5-ethanol signal verifying the inaccessibility of D5-EtGlu to intracellular b-glucuronidase. The next stage, currently ongoing, is a proof of mechanism in humans. D5-EtGlu is administered intravenously to confirmed lung cancer patients followed by breath analysis. D5-ethanol breath levels will be compared to cancer free individuals receiving the same dose of D5-EtGlu. Conclusions: Non-invasive breath testing has great potential to contribute to diagnosis for lung cancer including a potential role in screening. Our current work is evaluating the use of an administered probe to stimulate tumour-specific enzyme activity and produce a marker detectable on breath. Continued success could result in a sensitive and highly specific method for lung cancer early detection.

Performance monitoring of EBUS for the staging and diagnosis of lung cancer: auditing the Greater Manchester EBUS service against new national standards

Introduction

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a pivotal test in lung cancer staging and diagnosis, mandating robust audit and performance monitoring of EBUS services. We present the first regional cancer alliance EBUS performance audit against the new National EBUS specification.

Methods

Across the five EBUS centres in the Greater Manchester Cancer Alliance, data are recorded at the point of procedure, when pathological results are available and at 6 months postprocedure to review any further pathological sampling (eg, at surgical resection) and the outcome of clinical–radiological follow-up. Outcomes across all five centres were compared with national standards for all lung cancer EBUS procedures from 01 January 2017 to 31 December 2018.

Results

1899 lung cancer staging or diagnostic EBUS procedures were performed across the five centres during the study period; 1309 staging EBUS procedures and 590 diagnostic EBUS procedures. Major complications were seen in six cases (<1%). All five trusts demonstrated performance above that set national standards in key metrics for both staging and diagnostic EBUS, however the provision of adequate tissue for predictive marker testing was below national standards at one trust. Across Greater Manchester, 72% and 64% of patients had their EBUS procedure performed within 7 days of referral in 2017 and 2018, respectively. Only one out of five trusts met the national targets of >85% of procedures performed within 7 days of referral.

Conclusion

The National EBUS service specification is an important framework to drive the quality of EBUS services across the UK. Our data provide assurance of appropriate performance and safety while also highlighting specific areas for attention that can be addressed with the support of the cancer alliance.

Repeated sublethal freshwater exposures reduce the amoebic gill disease parasite, Neoparamoeba perurans, on Atlantic salmon

Freshwater bathing is one of the main treatment options available against amoebic gill disease (AGD) affecting multiple fish hosts in mariculture systems. Prevailing freshwater treatments are designed to be long enough to kill Neoparamoeba perurans, the ectoparasite causing AGD, which may select for freshwater tolerance. Here, we tested whether using shorter, sublethal freshwater treatment durations are a viable alternative to lethal ones for N. perurans (2-4 hr). Under in vitro conditions, gill-isolated N. perurans attached to plastic substrate in sea water lifted off after ≥2 min in freshwater, but survival was not impacted until 60 min. In an in vivo experiment, AGD-affected Atlantic salmon Salmo salar subjected daily to 30 min (sublethal to N. perurans) and 120 min (lethal to N. perurans) freshwater treatments for 6 days consistently reduced N. perurans cell numbers on gills (based on qPCR analysis) compared to daily 3 min freshwater or seawater treatments for 6 days. Our results suggest that targeting cell detachment rather than cell death with repeated freshwater treatments of shorter duration than typical baths could be used in AGD management. However, the consequences of modifying the intensity of freshwater treatment regimes on freshwater tolerance evolution in N. perurans populations require careful consideration.

Accuracy and cost-effectiveness of dynamic contrast-enhanced CT in the characterisation of solitary pulmonary nodules-the SPUtNIk study

INTRODUCTION

Solitary pulmonary nodules (SPNs) are common on CT. The most cost-effective investigation algorithm is still to be determined. Dynamic contrast-enhanced CT (DCE-CT) is an established diagnostic test not widely available in the UK currently.

METHODS AND ANALYSIS

The SPUtNIk study will assess the diagnostic accuracy, clinical utility and cost-effectiveness of DCE-CT, alongside the current CT and 18-flurodeoxyglucose-positron emission tomography) (18FDG-PET)-CT nodule characterisation strategies in the National Health Service (NHS). Image acquisition and data analysis for 18FDG-PET-CT and DCE-CT will follow a standardised protocol with central review of 10% to ensure quality assurance. Decision analytic modelling will assess the likely costs and health outcomes resulting from incorporation of DCE-CT into management strategies for patients with SPNs.

ETHICS AND DISSEMINATION

Approval has been granted by the South West Research Ethics Committee. Ethics reference number 12/SW/0206. The results of the trial will be presented at national and international meetings and published in an Health Technology Assessment (HTA) Monograph and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN30784948; Pre-results.

Differentially expressed proteins in gill and skin mucus of Atlantic salmon (Salmo salar) affected by amoebic gill disease

The external surfaces of fish, such as gill and skin, are covered by mucus, which forms a thin interface between the organism and water. Amoebic gill disease (AGD) is a parasitic condition caused by Neoparamoeba perurans that affects salmonids worldwide. This disease induces excessive mucus production in the gills. The host immune response to AGD is not fully understood, and research tools such as genomics and proteomics could be useful in providing further insight. Gill and skin mucus samples were obtained from Atlantic salmon (Salmo salar) which were infected with N. perurans on four successive occasions. NanoLC tandem mass spectrometry (MS/MS) was used to identify proteins in gill and skin mucus of Atlantic salmon affected by AGD. A total of 186 and 322 non-redundant proteins were identified in gill and skin mucus respectively, based on stringent filtration criteria, and statistics demonstrated that 52 gill and 42 skin mucus proteins were differentially expressed in mucus samples from AGD-affected fish. By generating protein-protein interaction networks, some of these proteins formed part of cell to cell signalling and inflammation pathways, such as C-reactive protein, apolipoprotein 1, granulin, cathepsin, angiogenin-1. In addition to proteins that were entirely novel in the context in the host response to N. perurans, our results have confirmed the presence of protein markers in mucus that have been previously predicted on the basis of modified mRNA expression, such as anterior gradient-2 protein, annexin A-1 and complement C3 factor. This first proteomic analysis of AGD-affected salmon provides new information on the effect of AGD on protein composition of gill and skin mucus. Future research should focus on better understanding of the role these components play in the response against infection with N. perurans.

Characterisation of an immunodominant, high molecular weight glycoprotein on the surface of infectious Neoparamoeba spp., causative agent of amoebic gill disease (AGD) in Atlantic salmon

Amoebic gill disease can be experimentally induced by the exposure of salmonids to Neoparamoeba spp. freshly isolated from infected fish, while cultured amoebae are non-infective. Results from our previous work suggested that one key difference between infectious and non-infectious Neoparamoeba were the highly glycosylated molecules in the glycocalyx. To characterise these surface glycans or glycoproteins we used a monoclonal antibody (mAb 44C12) specific to a surface molecule unique to infective parasites. This mAb recognised a carbohydrate epitope on a high molecular weight antigen (HMWA) that make up 15-19% of the total protein in a soluble extract of infectious parasites. The HMWA consisted of at least four glycoprotein subunits of molecular weight (MW) greater than 150 kDa that form disulfide-linked complexes of MW greater than 600 kDa. Chemical deglycosylation yielded at least four protein bands of approximate MW 46, 34, 28 and 18 kDA. While a similar HMWA complex was present in non-infective parasites, the glycoprotein subunits were of lower MW and exhibited differences in glycosylation. The four glycoproteins subunits recognised by mAb 44C12 were resistant to degradation by PNGase F, PNGase A, O-glycosidase plus β-1, 4-galactosidase, β-N-acetylglucosaminidase and neuraminidase. The major monosaccharides in the HMWA from infectious parasites were rhamnose, fucose, galactose, and mannose while sialic acids were absent. The carbohydrate portion constituted more than 90% of the total weight of the HMWA from infectious Neoparamoeba spp. Preliminary results indicate that immunisation of salmon with HMWA does not lead to protection against challenge infection; rather it may even have an immunosuppressive effect.

Economic appraisal of new technology in the absence of survival data--the case of total hip replacement

The development of total hip replacement has reached a level at which little further improvement in pain relief or quality of life can be expected from the introduction of new prosthetic technology. Rather, it is reasonable to expect longer trouble-free prosthetic life. This paper develops a mathematical model for a comparative economic appraisal of two types of prostheses, the conventional cemented one and the new cementless one. The lack of reliable survivorship data precludes reaching definite conclusions. However, by extensive sensitivity analysis with respect to a number of cost parameters the model can be used to derive conditions under which the cementless prosthesis is more cost effective. Expert medical judgement can then be used to gage whether these conditions are likely to be satisfied. The paper highlights the importance of collecting statistically valid performance data on any new medical technology from its first introduction. Without these, its full-scale adoption will be based largely on subjective grounds rather than a proper cost benefit analysis. It finally shows how both aspects--economic modeling and scientific data collection--form part of an integrated management programme for the economic evaluation of new medical technology.