PET-CT-guided versus CT-guided biopsy in suspected malignant pleural thickening: a randomised trial.

BACKGROUND: Pleural biopsy is the gold standard for diagnosis of pleural malignancy but a significant proportion will have an inconclusive biopsy despite ongoing clinical suspicion of malignancy. We investigated whether positron emission tomography-computed tomography (PET-CT) targeted pleural biopsy is superior to standard CT-guided pleural biopsy following an initial non-diagnostic biopsy. METHODS: The TARGET trial was a multicentre, parallel group randomised trial. Patients with a previous inconclusive pleural biopsy but an ongoing suspicion of pleural malignancy were randomised (1:1) to receive either CT-guided biopsy (standard care) or PET-CT followed by a targeted CT biopsy (intervention). The primary outcome was pleural malignancy correctly identified from the trial biopsy. RESULTS: Between September 2015 and September 2018, 59 participants were randomised from eight UK hospital sites: 29 to CT-only followed by targeted biopsy and 30 to PET-CT followed by targeted biopsy. The proportion of pleural malignancy correctly identified was similar between the groups (risk ratio 1.03 (95% CI 0.83-1.29); p=0.77). The sensitivity of the trial biopsy to identify pleural malignancy was 79% (95% CI 54-94%) in the CT-only group versus 81% (95% CI 54-96%) in the PET-CT group. CONCLUSIONS: The results do not support the practice of PET-CT to guide pleural biopsies in patients with a previous non-diagnostic biopsy. The diagnostic sensitivity in the CT-only group was higher than anticipated and supports the practice of repeating a CT-guided biopsy following an inconclusive result if clinical suspicion of malignancy persists.

Early Video-assisted Thoracoscopic Surgery or Intrapleural Enzyme Therapy in Pleural Infection: A Feasibility Randomized Controlled Trial. The Third Multicenter Intrapleural Sepsis Trial-MIST-3.

Rationale: Assessing the early use of video-assisted thoracoscopic surgery (VATS) or intrapleural enzyme therapy (IET) in pleural infection requires a phase III randomized controlled trial (RCT). Objectives: To establish the feasibility of randomization in a surgery-versus-nonsurgery trial as well as the key outcome measures that are important to identify relevant patient-centered outcomes in a subsequent RCT. Methods: The MIST-3 (third Multicenter Intrapleural Sepsis Trial) was a prospective multicenter RCT involving eight U.K. centers combining on-site and off-site surgical services. The study enrolled all patients with a confirmed diagnosis of pleural infection and randomized those with ongoing pleural sepsis after an initial period (as long as 24 h) of standard care to one of three treatment arms: continued standard care, early IET, or a surgical opinion with regard to early VATS. The primary outcome was feasibility based on >50% of eligible patients being successfully randomized, >95% of randomized participants retained to discharge, and >80% of randomized participants retained to 2 weeks of follow-up. The analysis was performed per intention to treat. Measurements and Main Results: Of 97 eligible patients, 60 (62%) were randomized, with 100% retained to discharge and 84% retained to 2 weeks. Baseline demographic, clinical, and microbiological characteristics of the patients were similar across groups. Median times to intervention were 1.0 and 3.5 days in the IET and surgery groups, respectively (P = 0.02). Despite the difference in time to intervention, length of stay (from randomization to discharge) was similar in both intervention arms (7 d) compared with standard care (10 d) (P = 0.70). There were no significant intergroup differences in 2-month readmission and further intervention, although the study was not adequately powered for this outcome. Compared with VATS, IET demonstrated a larger improvement in mean EuroQol five-dimension health utility index (five-level edition) from baseline (0.35) to 2 months (0.83) (P = 0.023). One serious adverse event was reported in the VATS arm. Conclusions: This is the first multicenter RCT of early IET versus early surgery in pleural infection. Despite the logistical challenges posed by the coronavirus disease (COVID-19) pandemic, the study met its predefined feasibility criteria, demonstrated potential shortening of length of stay with early surgery, and signals toward earlier resolution of pain and a shortened recovery with IET. The study findings suggest that a definitive phase III study is feasible but highlights important considerations and significant modifications to the design that would be required to adequately assess optimal initial management in pleural infection.The trial was registered on ISRCTN (number 18,192,121).

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.

A randomised controlled trial of intrapleural balloon intercostal chest drains to prevent drain displacement.

BACKGROUND: Chest drain displacement is a common clinical problem that occurs in 9-42% of cases and results in treatment failure or additional pleural procedures conferring unnecessary risk. A novel chest drain with an integrated intrapleural balloon may reduce the risk of displacement. METHODS: A prospective randomised controlled trial comparing the balloon drain to standard care (12 F chest drain with no balloon) with the primary outcome of objectively defined unintentional or accidental chest drain displacement. RESULTS: 267 patients were randomised (primary outcome data available in 257, 96.2%). Displacement occurred less frequently using the balloon drain (displacement 5 of 128, 3.9%; standard care displacement 13 of 129, 10.1%) but this was not statistically significant (OR for drain displacement 0.36, 95% CI 0.13-1.0, Chi-squared 1 degree of freedom (df)=2.87, p=0.09). Adjusted analysis to account for minimisation factors and use of drain sutures demonstrated balloon drains were independently associated with reduced drain fall-out rate (adjusted OR 0.27, 95% CI 0.08-0.87, p=0.028). Adverse events were higher in the balloon arm than the standard care arm (balloon drain 59 of 131, 45.0%; standard care 18 of 132, 13.6%; Chi-squared 1 df=31.3, p<0.0001). CONCLUSION: Balloon drains reduce displacement compared with standard drains independent of the use of sutures but are associated with increased adverse events specifically during drain removal. The potential benefits of the novel drain should be weighed against the risks, but may be considered in practices where sutures are not routinely used.

Prospective validation of the RAPID clinical risk prediction score in adult patients with pleural infection: the PILOT study.

BACKGROUND: Over 30% of adult patients with pleural infection either die and/or require surgery. There is no robust means of predicting at baseline presentation which patients will suffer a poor clinical outcome. A validated risk prediction score would allow early identification of high-risk patients, potentially directing more aggressive treatment thereafter. OBJECTIVES: To prospectively assess a previously described risk score (the RAPID (Renal (urea), Age, fluid Purulence, Infection source, Dietary (albumin)) score) in adults with pleural infection. METHODS: Prospective observational cohort study that recruited patients undergoing treatment for pleural infection. RAPID score and risk category were calculated at baseline presentation. The primary outcome was mortality at 3 months; secondary outcomes were mortality at 12 months, length of hospital stay, need for thoracic surgery, failure of medical treatment and lung function at 3 months. RESULTS: Mortality data were available in 542 out of 546 patients recruited (99.3%). Overall mortality was 10% at 3 months (54 out of 542) and 19% at 12 months (102 out of 542). The RAPID risk category predicted mortality at 3 months. Low-risk mortality (RAPID score 0-2): five out of 222 (2.3%, 95% CI 0.9 to 5.7%); medium-risk mortality (RAPID score 3-4): 21 out of 228 (9.2%, 95% CI 6.0 to 13.7%); and high-risk mortality (RAPID score 5-7): 27 out of 92 (29.3%, 95% CI 21.0 to 39.2%). C-statistics for the scores at 3 months and 12 months were 0.78 (95% CI 0.71-0.83) and 0.77 (95% CI 0.72-0.82), respectively. CONCLUSIONS: The RAPID score stratifies adults with pleural infection according to increasing risk of mortality and should inform future research directed at improving outcomes in this patient population.

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.

Is pleural infection associated with longer survival in mesothelioma? A population-based cohort study using data from Hospital Episode Statistics.

BACKGROUND: Historically pleural infection was thought to be associated with longer survival in thoracic malignancies. The aim of this population-based cohort study was to investigate this hypothesis in mesothelioma, using national data from a high incidence country. METHODS: Case records for all patients with mesothelioma seen in English hospitals between 01/01/2005 and 31/12/2014 were extracted from Hospital Episode Statistics using International Classification of Diseases Tenth Edition (ICD-10) codes. Episodes of pleural infection were identified. Linked mortality data was obtained from the Office of National Statistics. The primary outcome was all-cause mortality. The explanatory variable was pleural infection. Cox proportional hazards model was used to analyse survival, with pleural infection, chemotherapy and thoracic surgery handled as time-variable co-factors. RESULTS: Of 22,215 patients with mesothelioma, 512 (2.3%) developed pleural infection at some point in their illness. Overall median survival was 7.0 months (IQR 2.3-16.4). Pleural infection was associated with shorter survival in the immediate post-infection period (up to 30 days - HR 1.81, 95% CI 1.45-2.22) and longer term (>30 days - HR 1.81, 95% CI 1.63-1.99). Other factors associated with increased mortality were age, male gender and being diagnosed as an inpatient. Receiving chemotherapy and being less economically deprived were associated with longer survival. CONCLUSION: Pleural infection occurred in 2.3% of people with mesothelioma and was associated with shorter survival. This refutes previous reports suggesting pleural infection may be associated with better outcomes in thoracic malignancy.

Investigating unilateral pleural effusions: the role of cytology.

The vast majority of undiagnosed unilateral pleural effusions have fluid sent for cytological analysis. Despite widespread use, there is uncertainty about its sensitivity to diagnose malignant pleural effusions (MPEs). Our aim was to ascertain the utility of cytology using a large prospective cohort.Consecutive patients presenting with an undiagnosed unilateral pleural effusion were recruited to this UK-based study. All had pleural fluid sent for cytological analysis. Cytological sensitivity was based on the final diagnosis at 12 months, confirmed by two consultants.Over 8 years, 921 patients were recruited, of which 515 had a MPE. Overall sensitivity of fluid cytology to diagnose malignancy was 46% (95% CI 42-58%). There was variation in sensitivity depending on cancer primary, with mesothelioma (6%) and haematological malignancies (40%) being significantly lower than adenocarcinomas (79%). MPEs secondary to ovarian cancer had high pick-up rates (95%). In asbestos-exposed males with exudative effusions, the risk of MPE was 60%, but cytological sensitivity was 11%.This is the largest prospective study of pleural fluid cytology and informs discussions with patients about the likely requirement for investigations following thoracentesis. In patients presenting with a clinical suspicion of mesothelioma, cytological sensitivity is low, so more definitive investigations could be performed sooner.

Local Anaesthetic (Medical) Thoracoscopy Services in the UK.

BACKGROUND: Local anaesthetic thoracoscopy (LAT) is an important procedure in the management pathway of patients with pleural effusions, particularly those with suspected malignancy. The last survey evaluating the use and development of LAT services in the UK was conducted over a decade ago. OBJECTIVES: We performed a survey of LAT practices in the UK to explore procedural preferences and variations in practice. METHODS: The online survey was cascaded via regional pleural specialists to sites performing LAT. One response per site was accepted. RESULTS: Thirty-seven responses were received from England, Scotland and Wales. Most centres have regular access to a dedicated list and a designated area to perform LAT. 97% of the centres have at least 2 trained thoracoscopists. Some variation in practice is seen with patient preparation pre-procedure and medication use. Other procedures, such as insertion of indwelling pleural catheters and adhesiolysis, are not uncommon to be undertaken at the time of LAT. CONCLUSIONS: Overall, the results are comparable, excepting some minor variations in patient preparation pre-procedure. We hope that this survey functions as an information resource for centres developing a LAT service or for those considering expansion.

Zoledronic acid in the management of mesothelioma - a feasibility study (Zol-A Trial): study protocol for a randomised controlled trial.

BACKGROUND: Nitrogen containing bisphosphonates such as zoledronic acid (ZA) are known to contain certain anti-cancer properties. These have been investigated in the past in various cancers such as breast, prostate and colon. ZA in particular has shown promising results in pre-clinical studies. We propose a multicentre double-blind randomised controlled feasibility study to assess the recruitment and acceptability of ZA/placebo alongside chemotherapy in malignant pleural mesothelioma (MPM). METHODS: Patients will be recruited for a 13-month period from October 2016 to November 2017. Eligible patients will be identified via the regional mesothelioma multidisciplinary team meeting. Those who receive chemotherapy will be randomised to receive either ZA or placebo alongside their chemotherapy. Those who decline chemotherapy will be offered to join the trial on the non-randomised open-labelled arm of the trial. Patients will receive a maximum of six cycles of ZA/placebo, at three-weekly cycles. All patients will be followed up for six months from randomisation. Semi-structured interviews to gather data on acceptability of trial procedures, tolerability of ZA and other relevant information will take place after the participants have completed their six cycles of treatment. For a better understanding about non-participation in mesothelioma trials we also aim to interview those who decline to take part in the trial. DISCUSSION: The qualitative and quantitative data gathered in this feasibility trial will hopefully pave the way to designing a robust full phase III trial to investigate the potential synergistic effect of ZA and current standard treatment for MPM, cisplatin-pemetrexed combination chemotherapy. TRIAL REGISTRATION: ISRCTN Registry, ISRCTN45536692 . Registered on 9 August 2016. EudraCT no. 2015-004433-26.

Randomised controlled trial to compare the diagnostic yield of positron emission tomography CT (PET-CT) TARGETed pleural biopsy versus CT-guided pleural biopsy in suspected pleural malignancy (TARGET trial).

INTRODUCTION: Pleural malignancy, particularly malignant pleural mesothelioma (MPM) is increasing in incidence due to the long latency period from exposure to asbestos to development of the disease. MPM can be challenging to diagnose. For patients presenting without a pleural effusion, CT-guided biopsy remains the primary choice of biopsy, but the diagnostic sensitivity of this investigation is 70%-75%. Therefore, a proportion of patients will go on to require further biopsies. If the first biopsy is non-diagnostic, the chances of further non-diagnostic biopsies are high in MPM. METHODS: Target is a multicentre randomised controlled trial, aiming to recruit 78 patients over a 30-month period, from 10 centres in the UK. Patients will be randomised to either the standard arm which is a second CT-guided biopsy, or the interventional arm, a positron emission tomography-CT scan followed by a targeted CT-guided biopsy. Patients will be followed up for 12 months (patients recruited in the last 6 months of recruitment will have 6 months of follow-up). MPM biomarker mesothelin will be checked at baseline, 6 month and 12 month follow-up appointments where patients are able to attend these appointments. ETHICS AND DISSEMINATION: Ethical approval for this trial was granted by the South West-Exeter research and ethics committee (reference number 15/SW/0156). Results of the trial will be published in a peer-reviewed journal and presented at an international conference. TRIAL REGISTRATION NUMBER: ISRCTN 14024829; Pre-results.

BTS guideline for the investigation and management of malignant pleural mesothelioma.

The full guideline for the investigation and management of malignant pleural mesothelioma is published in Thorax. The following is a summary of the recommendations and good practice points. The sections referred to in the summary refer to the full guideline.

The role of procalcitonin in the management of pleural infection.

PURPOSE OF REVIEW: Pleural infection is a common problem associated with significant morbidity and mortality. Systemic or pleural fluid markers for reliably identifying pleural infection are limited. Procalcitonin (PCT) is known to be elevated in bacterial infection and is currently used for diagnosis and decision-making regarding antibiotic duration in respiratory infections. This review investigates if there is a role for serum and pleural fluid PCT (pf-PCT) in diagnosis and management of pleural infection. RECENT FINDINGS: Studies investigating the role of PCT have been limited by small patient numbers and heterogenous control populations. Overall, serum PCT (s-PCT) does not have a role superior to that of C-reactive protein (CRP) or leucocyte count (LCC) in diagnosing pleural infection or monitoring response to treatment. Similarly, pf-PCT demonstrated low sensitivity and specificity for diagnosing pleural infection. There was no role for PCT in determining which patients would require surgery as opposed to tube drainage alone. SUMMARY: There is currently insufficient evidence to recommend routine use of PCT for diagnosis and monitoring of pleural infection.

A prospective study to investigate the role of serial serum mesothelin in monitoring mesothelioma.

BACKGROUND: Radiological monitoring of malignant pleural mesothelioma (MPM) using modified RECIST criteria is limited by low sensitivity and inter-observer variability. Serial serum mesothelin measurement has shown utility in the assessment of treatment response during chemotherapy but has never been assessed in the longer term follow up of patients. METHODS: This is a single centre study of consecutive patients diagnosed with MPM who received chemotherapy or best supportive care (BSC). Serum mesothelin measurements with paired 6 monthly CT scans were performed following the completion of chemotherapy, or from baseline in the BSC group. Changes in mesothelin were correlated with radiological progression and overall survival. RESULTS: Forty-one patients with MPM were recruited and followed up for a minimum of 12 months (range 12-21 months). The majority of patients (n = 23) received chemotherapy with pemetrexed and cisplatin. Across the cohort a 10% rise in serum mesothelin could predict radiological progression with a sensitivity of 96% (IQR; 79-100) and specificity of 74% (IQR; 50-91). Sensitivity fell to 80% in sarcomatoid only disease. Patients with a rising mesothelin at 6 months had significantly worse overall survival (175 days) compared to stable/falling levels (448 days) (p = 0.003). CONCLUSIONS: This is the first study to assess serum mesothelin's ability to detect progression of MPM following chemotherapy or during BSC. A 10% rise in serum mesothelin level showed excellent sensitivity at predicting progressive disease. Mesothelin measurement has several advantages over serial CT imaging including reducing hospital visits and cost.

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 physiological consequences of different distributions of diffuse pleural thickening on CT imaging.

OBJECTIVE: Diffuse pleural thickening (DPT) refers to extensive visceral pleural fibrosis with adhesion formation to the parietal pleura obliterating the pleural space. The radiological definition of DPT remains controversial with most of the literature requiring the presence of an obliterated costophrenic angle (CPA) for defining DPT. We conducted a study to investigate the variable distributions of DPT and associated lung function deficit. METHODS: 85 patients referred to a pleural clinic with suspected pleural thickening were screened for our study. Data were collected from 37 patients with DPT confirmed on CT by size criteria (≥3 mm thick, ≥5 cm wide and ≥8 cm in length), and 21 controls with pleural plaques but no other pleuroparenchymal pathology. 27 patients were excluded. Groups were matched to age, body mass index and smoking history. RESULTS: The percentage of predicted forced vital capacity showed a gradual decline from 98.9% for the control group to 83.5% in the DPT without CPA obliteration group (p < 0.05), to 79.5% in the unilateral DPT group (p < 0.001) and 66.7% in the bilateral group (p < 0.001). Similar reductions were seen in the percentage of predicted total lung capacity in the DPT with no CPA obliteration group and the bilateral DPT group. CONCLUSION: Our study shows an incremental reduction in the forced vital capacity and total lung capacity in DPT without CPA obliteration, unilateral and bilateral DPT when compared with a matched control group. Advances in knowledge: Different distributions of DPT including no CPA obliteration can cause respiratory impairment, with bilateral DPT being the worst affected.