Lymphocyte predominance in blood, pleural fluid, and tumour stroma; a prognostic marker in pleural mesothelioma.

BACKGROUND: As promising novel treatments develop for malignant pleural mesothelioma (MPM), early prognostication has become increasingly important. Circulating and local inflammatory cells are known to play a significant role in other tumour types. We assessed the proportion of lymphocyte populations within blood, pleural fluid and tumour stroma to prognosticate patients with MPM at diagnosis. METHODS: Consecutive patients diagnosed with biopsy-proven MPM were prospectively recruited to an observational cohort study and followed up for a minimum of 7.5 years. Blood and pleural fluid results at presentation were extracted from the medical records. Biopsy specimens were independently reviewed by 2 pathologists who scored the degree of lymphocytic and neutrophilic infiltration. RESULTS: Baseline results were available for 184 patients. The predominant pleural fluid cell type was calculable for 84 patients and 118 patients had biopsy specimens available for review. A low blood neutrophil/lymphocyte ratio (NLR < 4) inferred a better prognosis with a median survival of 420 days versus 301 days (p < 0.01). Survival was better for patients with a lymphocyte-predominant pleural effusion (430 vs 306 days, p < 0.01). Lymphocyte infiltration of tumour stroma was also associated with improved survival (n = 92, survival 430 days) compared with neutrophilic or acellular samples (n = 26, survival 342 days p < 0.01). In multivariable modelling lymphocyte predominance in blood, pleural fluid and tumour stroma were all associated with a better prognosis. CONCLUSIONS: Lymphocyte predominance within tumour stroma, pleural fluid or blood infers a better prognosis in patients with MPM.

The priorities of people with mesothelioma and their carers: A qualitative interview study of trial participation and treatment decisions.

PURPOSE: Treatment options for mesothelioma are increasing, as are the number of clinical trials available to patients. However, little is known about patients' and relatives' priorities when making decisions about treatment and trial participation. The aim of this study was to provide insight into people's experiences of participating in clinical research and explore the factors influencing decision-making. METHODS: Face to face, semi-structured interviews were undertaken with mesothelioma patients who were participating in the TILT trial (a randomised trial of intra-pleural immunotherapy) and their relatives. Interviews were audio-recorded, transcribed and analysed thematically. RESULTS: Twelve people were interviewed, comprising five mesothelioma patients and seven relatives. Four themes were identified relating to the experience of mesothelioma: physicality, quality of life, uncertainty and risk, and planning for an unpredictable future. A further theme related to attitudes to research participation. PARTICIPANTS: valued physical strength and were careful not to jeopardise this with potential side effects of medication. Quality of life was important and was often prioritised over survival. Participants found ambiguity challenging and sought certainty, potentially in response to the uncertainty surrounding their future. The desire for certainty impacted on risk perception; an important factor in decision-making. Relatives often advocated on behalf of patients and were more reluctant about research participation due to concern about potential risks. CONCLUSION: The study confirmed previous qualitative findings around physicality, stoicism and uncertainty, building on these themes to highlight their influence on decision-making. Important findings for practice include the challenges associated with risk communication and the differing care needs and attitudes to research of relatives.

Aerosol emission from the respiratory tract: an analysis of aerosol generation from oxygen delivery systems.

INTRODUCTION: continuous positive airway pressure (CPAP) and high-flow nasal oxygen (HFNO) provide enhanced oxygen delivery and respiratory support for patients with severe COVID-19. CPAP and HFNO are currently designated as aerosol-generating procedures despite limited high-quality experimental data. We aimed to characterise aerosol emission from HFNO and CPAP and compare with breathing, speaking and coughing. MATERIALS AND METHODS: Healthy volunteers were recruited to breathe, speak and cough in ultra-clean, laminar flow theatres followed by using CPAP and HFNO. Aerosol emission was measured using two discrete methodologies, simultaneously. Hospitalised patients with COVID-19 had cough recorded using the same methodology on the infectious diseases ward. RESULTS: In healthy volunteers (n=25 subjects; 531 measures), CPAP (with exhalation port filter) produced less aerosol than breathing, speaking and coughing (even with large >50 L/min face mask leaks). Coughing was associated with the highest aerosol emissions of any recorded activity. HFNO was associated with aerosol emission, however, this was from the machine. Generated particles were small (<1 µm), passing from the machine through the patient and to the detector without coalescence with respiratory aerosol, thereby unlikely to carry viral particles. More aerosol was generated in cough from patients with COVID-19 (n=8) than volunteers. CONCLUSIONS: In healthy volunteers, standard non-humidified CPAP is associated with less aerosol emission than breathing, speaking or coughing. Aerosol emission from the respiratory tract does not appear to be increased by HFNO. Although direct comparisons are complex, cough appears to be the main aerosol-generating risk out of all measured activities.

Krebs von den Lungen 6 (KL-6) as a marker for disease severity and persistent radiological abnormalities following COVID-19 infection at 12 weeks.

INTRODUCTION: Acute presentations of COVID-19 infection vary, ranging from asymptomatic carriage through to severe clinical manifestations including acute respiratory distress syndrome (ARDS). Longer term sequelae of COVID-19 infection includes lung fibrosis in a proportion of patients. Krebs von den Lungen 6 (KL-6) is a mucin like glycoprotein that has been proposed as a marker of pulmonary epithelial cell injury. We sought to determine whether KL-6 was a marker of 1) the severity of acute COVID-19 infection, or 2) the persistence of symptoms/radiological abnormalities at medium term follow up. METHODS: Prospective single centre observational study. RESULTS: Convalescent KL-6 levels were available for 93 patients (male 63%, mean age 55.8 years) who attended an 12-week follow up appointment after being admitted to hospital with COVID-19. For 67 patients a baseline KL-6 result was available for comparison. There was no significant correlations between baseline KL-6 and the admission CXR severity score or clinical severity NEWS score. Furthermore, there was no significant difference in the baseline KL-6 level and an initial requirement for oxygen on admission or the severity of acute infection as measured at 28 days. There was no significant difference in the 12-week KL-6 level and the presence or absence of subjective breathlessness but patients with abnormal CT scans at 12 weeks had significantly higher convalescent KL-6 levels compared to the remainder of the cohort (median 1101 IU/ml vs 409 IU/ml). CONCLUSIONS: The association between high KL-6 levels at 12 weeks and persisting CT abnormalities (GGO/fibrosis), is a finding that requires further exploration. Whether KL-6 may help differentiate those patients with persisting dyspnoea due to complications rather than deconditioning or dysfunctional breathing alone, is an important future research question.

Patient outcomes after hospitalisation with COVID-19 and implications for follow-up: results from a prospective UK cohort.

The longer-term consequences of SARS-CoV-2 infection are uncertain. Consecutive patients hospitalised with COVID-19 were prospectively recruited to this observational study (n=163). At 8-12 weeks postadmission, survivors were invited to a systematic clinical follow-up. Of 131 participants, 110 attended the follow-up clinic. Most (74%) had persistent symptoms (notably breathlessness and excessive fatigue) and limitations in reported physical ability. However, clinically significant abnormalities in chest radiograph, exercise tests, blood tests and spirometry were less frequent (35%), especially in patients not requiring supplementary oxygen during their acute infection (7%). Results suggest that a holistic approach focusing on rehabilitation and general well-being is paramount.

The Prevalence and Clinical Relevance of Nonexpandable Lung in Malignant Pleural Mesothelioma. A Prospective, Single-Center Cohort Study of 229 Patients.

Rationale: Nonexpandable lung is a recognized phenomenon that can create management challenges in patients with mesothelioma. Its prevalence and clinical importance are unknown.Objectives: The aim of this study was to describe the prevalence of nonexpandable lung and to evaluate whether there was any association between nonexpandable lung and survival in a clinical cohort of patients with mesothelioma.Methods: This was a prospective, observational cohort study of patients with mesothelioma who were seen in a single center between March 1, 2008, and August 3, 2017. Baseline characteristics were collected at diagnosis. Serial chest radiographs were assessed for the presence of pleural effusions and nonexpandable lung (defined as a lack of lung expansion after pleural aspiration or drainage). Patients were followed until they died or were censored on March 14, 2019.Results: Of 229 patients, 192 (82.7%) had a pleural effusion at presentation, and nonexpandable lung was observed in 64 of these 192 patients (33.3%). Breathlessness and cough were more frequent in patients with pleural effusions, especially in those with underlying nonexpandable lung, whereas chest pain was more prevalent in patients without effusions. Patients with pleural effusions, both with and without underlying nonexpandable lung, were more likely to have epithelioid or early-stage disease and to receive chemotherapy than patients with no pleural effusion. Nonexpandable lung was an independent risk factor for short survival, with a hazard ratio for mortality of 1.80 (95% confidence interval, 1.16-2.80) compared with patients without nonexpandable lung. The presence of a pleural effusion did not appear to be associated with a worse prognosis compared with patients with an effusion (adjusted hazard ratio, 1.86; 95% confidence interval, 0.93-3.72).Conclusions: This is the first study to describe the prevalence and clinical implications of nonexpandable lung in mesothelioma. It demonstrates that nonexpandable lung is a relatively common phenomenon that is associated with significant symptomatology and shorter survival.Keywords: mesothelioma; nonexpandable lung; pleural effusion.

Outpatient Talc Administration by Indwelling Pleural Catheter for Malignant Effusion.

BACKGROUND: Malignant pleural effusion affects more than 750,000 persons each year across Europe and the United States. Pleurodesis with the administration of talc in hospitalized patients is the most common treatment, but indwelling pleural catheters placed for drainage offer an ambulatory alternative. We examined whether talc administered through an indwelling pleural catheter was more effective at inducing pleurodesis than the use of an indwelling pleural catheter alone. METHODS: Over a period of 4 years, we recruited patients with malignant pleural effusion at 18 centers in the United Kingdom. After the insertion of an indwelling pleural catheter, patients underwent drainage regularly on an outpatient basis. If there was no evidence of substantial lung entrapment (nonexpandable lung, in which lung expansion and pleural apposition are not possible because of visceral fibrosis or bronchial obstruction) at 10 days, patients were randomly assigned to receive either 4 g of talc slurry or placebo through the indwelling pleural catheter on an outpatient basis. Talc or placebo was administered on a single-blind basis. Follow-up lasted for 70 days. The primary outcome was successful pleurodesis at day 35 after randomization. RESULTS: The target of 154 patients undergoing randomization was reached after 584 patients were approached. At day 35, a total of 30 of 69 patients (43%) in the talc group had successful pleurodesis, as compared with 16 of 70 (23%) in the placebo group (hazard ratio, 2.20; 95% confidence interval, 1.23 to 3.92; P=0.008). No significant between-group differences in effusion size and complexity, number of inpatient days, mortality, or number of adverse events were identified. No significant excess of blockages of the indwelling pleural catheter was noted in the talc group. CONCLUSIONS: Among patients without substantial lung entrapment, the outpatient administration of talc through an indwelling pleural catheter for the treatment of malignant pleural effusion resulted in a significantly higher chance of pleurodesis at 35 days than an indwelling catheter alone, with no deleterious effects. (Funded by Becton Dickinson; EudraCT number, 2012-000599-40 .).

Exploring the characteristics of patients with mesothelioma who chose active symptom control over chemotherapy as first-line treatment: a prospective, observational, single centre study.

BACKGROUND: Mesothelioma is an aggressive thoracic tumour with a poor prognosis. The only treatment that extends survival is chemotherapy. However, in the UK, up to 50% of patients who are suitable for chemotherapy choose not to receive it, opting for active symptom control instead. The aim of this prospective, single-centre observational study was to describe the characteristics of patients who chose active symptom control over chemotherapy and explore their reasons for doing so. METHODS: Two hundred consecutive patients with mesothelioma from one UK centre were included. Eligibility for chemotherapy and choice of first-line treatment were recorded prospectively. Patient characteristics and outcomes were compared using descriptive statistics, regression analysis and survival analysis. Reasons for choosing active symptom control over chemotherapy were extracted, retrospectively. RESULTS: People who chose active symptom control were older, more likely to be female and had worse performance statuses than patients who received front-line chemotherapy. Concern over side effects, the modest survival benefit and previous adverse experiences with chemotherapy were reported as reasons for the decision. Median survival was 13.9 months in the chemotherapy group compared with 6.7 months in the active symptom control group. CONCLUSIONS: This is the first study to describe the characteristics of patients with mesothelioma who chose active symptom control over chemotherapy, in the front-line setting. Important differences were seen between this group and patients who received chemotherapy, although confounding is likely to have affected some outcomes. Future research could use qualitative methods to explore patients' reasons for choosing active symptom control, and to further elucidate the decision-making process.

The role of serum procalcitonin in establishing the diagnosis and prognosis of pleural infection.

BACKGROUND: Bacterial pleural infection requires prompt identification to enable appropriate investigation and treatment. In contrast to commonly used biomarkers such as C-reactive protein (CRP) and white cell count (WCC), which can be raised due to non-infective inflammatory processes, procalcitonin (PCT) has been proposed as a specific biomarker of bacterial infection. The utility of PCT in this role is yet to be validated in a large prospective trial. This study aimed to identify whether serum PCT is superior to CRP and WCC in establishing the diagnosis of bacterial pleural infection. METHODS: Consecutive patients presenting to a tertiary pleural service between 2008 and 2013 were recruited to a well-established pleural disease study. Consent was obtained to store pleural fluid and relevant clinical information. Serum CRP, WCC and PCT were measured. A diagnosis was agreed upon by two independent consultants after a minimum of 12 months. The study was performed and reported according to the STARD reporting guidelines. RESULTS: 80/425 patients enrolled in the trial had a unilateral pleural effusion secondary to infection. 10/80 (12.5%) patients had positive pleural fluid microbiology. Investigations for viral causes of effusion were not performed. ROC curve analysis of 425 adult patients with unilateral undiagnosed pleural effusions showed no statistically significant difference in the diagnostic utility of PCT (AUC 0.77), WCC (AUC 0.77) or CRP (AUC 0.85) for the identification of bacterial pleural infection. Serum procalcitonin >0.085 µg/l has a sensitivity, specificity, negative predictive value and positive predictive value of 0.69, 0.80, 0.46 and 0.91 respectively for the identification of pleural infection. The diagnostic utility of procalcitonin was not affected by prior antibiotic use (p = 0.80). CONCLUSIONS: The study presents evidence that serum procalcitonin is not superior to CRP and WCC for the diagnosis of bacterial pleural infection. The study suggests routine procalcitonin testing in all patients with unilateral pleural effusion is not beneficial however further investigation may identify specific patient subsets that may benefit. TRIAL REGISTRATION: The trial was registered with the UK Clinical Research Network ( UKCRN ID 8960 ). The trial was approved by the South West Regional Ethics Committee (Ethical approval number 08/H0102/11).

Nonmalignant Pleural Effusions: A Prospective Study of 356 Consecutive Unselected Patients.

BACKGROUND: Pleural effusion secondary to a nonmalignant cause can represent significant morbidity and mortality. Nonmalignant pleural effusion (NMPE) is common, with congestive heart failure representing the leading cause. Despite this, there are limited data on mortality risk and associated prognostic factors. METHODS: We recruited 782 consecutive patients presenting to a pleural service between March 2008 and March 2015 with an undiagnosed pleural effusion. Further analysis was conducted in 356 patients with NMPE. Pleural biochemical analysis, cytologic analysis, thoracic ultrasonography, and chest radiography were performed. Echocardiography, CT imaging, radiologically guided biopsy, and medical thoracoscopy were undertaken as clinically indicated. Patients were followed for a minimum duration of 12 months, with the final diagnosis decided through independent review by two respiratory consultants. RESULTS: Of the 782 patients, 356 were diagnosed with NMPE (46%). These patients had a mean age of 68 years (SD, 17 years) with 69% of them being men. Patients with cardiac, renal, and hepatic failure had 1-year mortality rates of 50%, 46%, and 25%, respectively. Bilateral effusions (hazard ratio [HR], 3.55; 95% CI, 2.22-5.68) and transudative effusions (HR, 2.78; 95% CI, 1.81-4.28) were associated with a worse prognosis in patients with NMPE, with a 57% and 43% 1-year mortality rate, respectively. CONCLUSIONS: This is the largest prospectively collected series in patients with NMPE, demonstrating that cases secondary to organ dysfunction have extremely high 1-year mortality. In addition, the presence of bilateral and transudative effusions is an indicator of increased mortality. Clinicians should be aware of these poor prognostic features and guide management accordingly.

Prophylactic radiotherapy for the prevention of procedure-tract metastases after surgical and large-bore pleural procedures in malignant pleural mesothelioma (SMART): a multicentre, open-label, phase 3, randomised controlled trial.

BACKGROUND: The use of prophylactic radiotherapy to prevent procedure-tract metastases (PTMs) in malignant pleural mesothelioma remains controversial, and clinical practice varies worldwide. We aimed to compare prophylactic radiotherapy with deferred radiotherapy (given only when a PTM developed) in a suitably powered trial. METHODS: We did a multicentre, open-label, phase 3, randomised controlled trial in 22 UK hospitals of patients with histocytologically proven mesothelioma who had undergone large-bore pleural interventions in the 35 days prior to recruitment. Eligible patients were randomised (1:1), using a computer-generated sequence, to receive immediate radiotherapy (21 Gy in three fractions within 42 days of the pleural intervention) or deferred radiotherapy (same dose given within 35 days of PTM diagnosis). Randomisation was minimised by histological subtype, surgical versus non-surgical procedure, and pleural procedure (indwelling pleural catheter vs other). The primary outcome was the incidence of PTM within 7 cm of the site of pleural intervention within 12 months from randomisation, assessed in the intention-to-treat population. This trial is registered with ISRCTN, number ISRCTN72767336. FINDINGS: Between Dec 23, 2011, and Aug 4, 2014, we randomised 203 patients to receive immediate radiotherapy (n=102) or deferred radiotherapy (n=101). The patients were well matched at baseline. No significant difference was seen in PTM incidence in the immediate and deferred radiotherapy groups (nine [9%] vs 16 [16%]; odds ratio 0·51 [95% CI 0·19-1·32]; p=0·14). The only serious adverse event related to a PTM or radiotherapy was development of a painful PTM within the radiotherapy field that required hospital admission for symptom control in one patient who received immediate radiotherapy. Common adverse events of immediate radiotherapy were skin toxicity (grade 1 in 50 [54%] and grade 2 in four [4%] of 92 patients vs grade 1 in three [60%] and grade 2 in two [40%] of five patients in the deferred radiotherapy group who received radiotherapy for a PTM) and tiredness or lethargy (36 [39%] in the immediate radiotherapy group vs two [40%] in the deferred radiotherapy group) within 3 months of receiving radiotherapy. INTERPRETATION: Routine use of prophylactic radiotherapy in all patients with mesothelioma after large-bore thoracic interventions is not justified. FUNDING: Research for Patient Benefit Programme from the UK National Institute for Health Research.

Unilateral Pleural Effusions with More Than One Apparent Etiology. A Prospective Observational Study.

RATIONALE: Evaluation of a pleural effusion has historically focused on establishing a single etiology. Pleural fluid may accumulate through multiple pathophysiological processes. The prevalence of multiple causes for pleural effusions has not been established. The identification of contributing processes may improve clinical outcomes. OBJECTIVES: The objective of this prospectively collected case series was to establish the prevalence and nature of multiple etiologies for a unilateral pleural effusion. METHODS: Consecutive patients presenting with an undiagnosed unilateral pleural effusion were recruited at a tertiary pleural center. Patients underwent a comprehensive structured diagnostic clinical evaluation and were followed up for a minimum of 12 months, after which one or more diagnoses were recorded independently by two experienced clinicians. MEASUREMENTS AND MAIN RESULTS: One hundred thirty patients were recruited to the study over a 24-month period, and 126 patients completed follow up. Altogether, 88 patients (70%) had a single cause for their pleural effusion, and 38 (30%) had multiple causes. Serum N-terminal pro-brain natriuretic peptide (NT-pro BNP) greater than or equal to 1,500 pg/ml was predictive of multiple etiologies. NT-pro BNP had a sensitivity and specificity of 79 and 88%, respectively, for establishing heart failure as a primary or contributory cause. Thirteen patients with a malignant pleural effusion also had an NT-pro BNP greater than or equal to 1,500 pg/ml. CONCLUSIONS: This study is the first to estimate the prevalence of more than one identifiable cause for a unilateral pleural effusion. Out of 130 study subjects, 38 (30%) had multiple causes for an effusion. The identification of multiple pathologies underlying an accumulation of fluid in the pleural space may be important in determining optimum treatment and improving patients' symptoms.

The efficacy of indwelling pleural catheter placement versus placement plus talc sclerosant in patients with malignant pleural effusions managed exclusively as outpatients (IPC-PLUS): study protocol for a randomised controlled trial.

BACKGROUND: Malignant pleural effusions (MPEs) remain a common problem, with 40,000 new cases in the United Kingdom each year and up to 250,000 in the United States. Traditional management of MPE usually involves an inpatient stay with placement of a chest drain, followed by the instillation of a pleural sclerosing agent such as talc, which aims to minimise further fluid build-up. Despite a good success rate in studies, this approach can be expensive, time-consuming and inconvenient for patients. More recently, an alternative method has become available in the form of indwelling pleural catheters (IPCs), which can be inserted and managed in an outpatient setting. It is currently unknown whether combining talc pleurodesis with IPCs will provide improved pleural symphysis rates over those of IPCs alone. METHODS/DESIGN: IPC-PLUS is a patient-blind, multicentre randomised controlled trial (RCT) comparing the combination of talc with an IPC to the use of an IPC alone for inducing pleurodesis in MPEs. The primary outcome is successful pleurodesis at five weeks post-randomisation. This study will recruit 154 patients, with an interim analysis for efficacy after 100 patients, and aims to help to define the future gold standard for outpatient management of patients with symptomatic MPEs. DISCUSSION: IPC-PLUS is the first RCT to examine the practicality and utility of talc administered via an IPC. The study remains in active recruitment and has the potential to significantly alter how patients requiring pleurodesis for MPE are approached in the future. TRIAL REGISTRATION: This trial was registered with Current Controlled Trials (identifier: ISRCTN73255764 ) on 23 August 2012.

A randomised controlled trial of intravenous zoledronic acid in malignant pleural disease: a proof of principle pilot study.

INTRODUCTION: Animal studies have shown Zoledronic Acid (ZA) may diminish pleural fluid accumulation and tumour bulk in malignant pleural disease (MPD). We performed a pilot study to evaluate its effects in humans. METHODS: We undertook a single centre, double-blind, placebo-controlled trial in adults with MPD. Patients were randomised (1:1) to receive 2 doses of intravenous ZA or placebo, 3 weeks apart and were followed-up for 6 weeks. The co-primary outcomes were change in Visual Analogue Scale (VAS) score measured breathlessness during trial follow-up and change in the initial area under the curve (iAUC) on thoracic Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) from randomisation to week 5. Multiple secondary endpoints were also evaluated. RESULTS: Between January 2010 and May 2013, 30 patients were enrolled, 24 randomised and 4 withdrew after randomisation (1 withdrew consent; 3 had a clinical decline). At baseline, the ZA group were more breathless, had more advanced disease on radiology and worse quality of life than the placebo group. There was no significant difference between the groups with regards change in breathlessness (Adjusted mean difference (AMD) 4.16 (95%CI -4.7 to 13.0)) or change in DCE-MRI iAUC (AMD -15.4 (95%CI -58.1 to 27.3). Two of nine (22%) in the ZA arm had a >10% improvement by modified RECIST (vs 0/11 who received placebo). There was no significant difference in quality of life measured by the QLQ-C30 score (global QOL: AMD -4.1 (-13.0 to 4.9)), side effects or serious adverse event rates. CONCLUSIONS: This is the first human study to evaluate ZA in MPD. The study is limited by small numbers and imbalanced baseline characteristics. Although no convincing treatment effect was identified, potential benefits for specific subgroups of patients cannot be excluded. This study provides important information regarding the feasibility of future trials to evaluate the effects of ZA further. TRIAL REGISTRATION: UK Clinical Research Network ID 8877 ISRCTN17030426 www.isrctn.com.

Pleural fluid adenosine deaminase (pfADA) in the diagnosis of tuberculous effusions in a low incidence population.

INTRODUCTION: Previous studies have assessed the diagnostic ability of pleural fluid adenosine deaminase (pfADA) in detecting tuberculous pleural effusions, with good specificity and sensitivity reported. However, in North Western Europe pfADA is not routinely used in the investigation of a patient with an undiagnosed pleural effusion, mainly due to a lack of evidence as to its utility in populations with low mycobacterium tuberculosis (mTB) incidence. METHODS: Patients presenting with an undiagnosed pleural effusion to a tertiary pleural centre in South-West England over a 3 year period, were prospectively recruited to a pleural biomarker study. Pleural fluid from consecutive patients with robust 12-month follow up data and confirmed diagnosis were sent for pfADA analysis. RESULTS: Of 338 patients enrolled, 7 had confirmed tuberculous pleural effusion (2%). All mTB effusions were lymphocyte predominant with a median pfADA of 72.0 IU/L (range- 26.7 to 91.5) compared to a population median of 12.0 IU/L (range- 0.3 to 568.4). The optimal pfADA cut off was 35 IU/L, which had a negative predictive value (NPV) of 99.7% (95% CI; 98.2-99.9%) for the exclusion of mTB, and sensitivity of 85.7% (95% CI; 42.2-97.6%) with an area under the curve of 0.88 (95% CI; 0.732-1.000). DISCUSSION: This is the first study examining the diagnostic utility of pfADA in a low mTB incidence area. The chance of an effusion with a pfADA under 35 IU/L being of tuberculous aetiology was negligible. A pfADA of over 35 IU/L in lymphocyte-predominant pleural fluid gives a strong suspicion of mTB.

Protocol for the surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial): an RCT evaluating whether prophylactic radiotherapy reduces the incidence of procedure tract metastases.

INTRODUCTION: Patients with malignant pleural mesothelioma (MPM) may develop painful 'procedure tract metastasis' (PTM) at the site of previous pleural interventions. Prophylactic radiotherapy has been used to minimise this complication; however, three small randomised trials have shown conflicting results regarding its effectiveness. The surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial) is a suitably powered, multicentre, randomised controlled trial, designed to evaluate the efficacy of prophylactic radiotherapy within 42 days of pleural instrumentation in preventing the development of PTM in MPM. METHODS AND ANALYSIS: 203 patients with a histocytologically proven diagnosis of MPM, who have undergone a large bore pleural intervention (thoracic surgery, large bore chest drain, indwelling pleural catheter or local anaesthetic thoracoscopy) in the previous 35 days, will be recruited from UK hospitals. Patients will be randomised (1:1) to receive immediate radiotherapy (21 Gy in 3 fractions over 3 working days within 42 days of the pleural intervention) or deferred radiotherapy (21 Gy in 3 fractions over 3 working days given if a PTM develops). Patients will be followed up for 12 months. The primary outcome measure is the rate of PTM until death or 12 months (whichever is sooner), as defined by the presence of a clinically palpable nodule of at least 1 cm diameter felt within 7 cm of the margins of the procedure site as confirmed by two assessors. Secondary outcome measures include chest pain, quality of life, analgaesic requirements, healthcare utilisation and safety (including radiotherapy toxicity). ETHICS AND DISSEMINATION: The trial has received ethical approval from the Southampton B Research Ethics Committee (11/SC/0408). There is a Trial Steering Committee, including independent members and a patient and public representative. The trial results will be published in a peer-reviewed journal and presented at international conferences. TRIAL REGISTRATION NUMBER: ISRCTN72767336.

Survival in Patients With Malignant Pleural Effusions Who Developed Pleural Infection: A Retrospective Case Review From Six UK Centers.

OBJECTIVE: Malignant pleural effusion (MPE) incidence is increasing, and prognosis remains poor. Indwelling pleural catheters (IPCs) relieve symptoms but increase the risk of pleural infection. We reviewed cases of pleural infection in patients with IPCs for MPE from six UK centers between January 1, 2005, and January 31, 2014. METHODS: Survival in patients with pleural infection was compared with 788 patients with MPE (known as the LENT [pleural fluid lactate dehydrogenase, Eastern Cooperative Oncology Group performance status, serum neutrophil to lymphocyte ratio, and tumor type] cohort) and with national statistics. RESULTS: Of 672 IPCs inserted, 25 (3.7%) became infected. Most patients (20 of 25) had mesothelioma or lung cancer. Median survival in the pleural infection cohort appeared longer than in the LENT cohort, although this result did not achieve significance (386 days vs 132 days; hazard ratio, 0.67; P = .07). Median survival with mesothelioma and pleural infection was twice as long as national estimates for mesothelioma survival (753 days vs < 365 days) and double the median survival of patients with mesothelioma in the LENT cohort (339 days; 95% CI, nonoverlapping). Survival with lung and breast cancer did not differ significantly between the groups. Sixty-one percent of patients experienced early infection. There was no survival difference between patients with early and late infection (P = .6). CONCLUSIONS: This small series of patients with IPCs for MPE suggests pleural infection may be associated with longer survival, particularly in patients with mesothelioma. Results did not achieve significance, and a larger study is needed to explore this relationship further and investigate whether the local immune response, triggered by infection, is able to modulate mesothelioma progression.

Predicting survival in malignant pleural effusion: development and validation of the LENT prognostic score.

BACKGROUND: Malignant pleural effusion (MPE) causes debilitating breathlessness and predicting survival is challenging. This study aimed to obtain contemporary data on survival by underlying tumour type in patients with MPE, identify prognostic indicators of overall survival and develop and validate a prognostic scoring system. METHODS: Three large international cohorts of patients with MPE were used to calculate survival by cell type (univariable Cox model). The prognostic value of 14 predefined variables was evaluated in the most complete data set (multivariable Cox model). A clinical prognostic scoring system was then developed and validated. RESULTS: Based on the results of the international data and the multivariable survival analysis, the LENT prognostic score (pleural fluid lactate dehydrogenase, Eastern Cooperative Oncology Group (ECOG) performance score (PS), neutrophil-to-lymphocyte ratio and tumour type) was developed and subsequently validated using an independent data set. Risk stratifying patients into low-risk, moderate-risk and high-risk groups gave median (IQR) survivals of 319 days (228-549; n=43), 130 days (47-467; n=129) and 44 days (22-77; n=31), respectively. Only 65% (20/31) of patients with a high-risk LENT score survived 1 month from diagnosis and just 3% (1/31) survived 6 months. Analysis of the area under the receiver operating curve revealed the LENT score to be superior at predicting survival compared with ECOG PS at 1 month (0.77 vs 0.66, p<0.01), 3 months (0.84 vs 0.75, p<0.01) and 6 months (0.85 vs 0.76, p<0.01). CONCLUSIONS: The LENT scoring system is the first validated prognostic score in MPE, which predicts survival with significantly better accuracy than ECOG PS alone. This may aid clinical decision making in this diverse patient population.

A prospective trial evaluating the role of mesothelin in undiagnosed pleural effusions.

Mesothelin has been proposed as a useful tool in the diagnosis of malignant pleural mesothelioma (MPM). We aimed to examine its diagnostic utility and the impact of renal impairment on results. We prospectively recruited 230 patients with new undiagnosed pleural effusions, testing serum (n=216) and pleural fluid (n=206) mesothelin (by ELISA) during the initial consultation. 28 (12%) out of 230 patients had MPM. Serum mesothelin gave sensitivity 59.3%, specificity 64.7%, negative predictive value (NPV) 91.2%, positive predictive value (PPV) 20.5%, and pleural fluid sensitivity 72.0%, specificity 87.5%, NPV 95.5%, PPV 46.2% for distinguishing effusions due to MPM. In a matched comparison, diagnostic characteristics of pleural fluid mesothelin were superior to serum (p=0.0001). Serum mesothelin levels in patients without MPM were higher in patients with renal impairment (p=0.007) while pleural fluid levels were unaffected. 19 (54%) out of 35 patients with a benign pleural effusion and an estimated glomerular filtration rate ≤ 59 mL · min(-1) had a false-positive serum mesothelin result. The diagnostic accuracy of pleural fluid mesothelin is superior to that of serum and is unaffected by renal function. In patients with a low pre-test probability of mesothelioma, a negative mesothelin test could be reassuring, because of its high NPV. Routine use of mesothelin testing in undiagnosed pleural effusions at presentation appears to be unhelpful.