British Thoracic Society Guideline for the investigation and management of malignant pleural mesothelioma

GOECP/SEOR clinical guidelines on radiotherapy for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare tumor with poor prognosis and rising incidence. Palliative care is common in MPM as radical treatment with curative intent is often not possible due to metastasis or extensive locoregional involvement. Numerous therapeutic advances have been made in recent years, including the use of less aggressive surgical techniques associated with lower morbidity and mortality (e.g., pleurectomy/decortication), technological advancements in the field of radiotherapy (intensity-modulated radiotherapy, image-guided radiotherapy, stereotactic body radiotherapy, proton therapy), and developments in systemic therapies (chemotherapy and immunotherapy). These improvements have had as yet only a modest effect on local control and survival. Advances in the management of MPM and standardization of care are hampered by the evidence to date, limited by high heterogeneity among studies and small sample sizes. In this clinical guideline prepared by the oncological group for the study of lung cancer of the Spanish Society of Radiation Oncology, we review clinical, histologic, and therapeutic aspects of MPM, with a particular focus on all aspects relating to radiotherapy, including the current evidence base, associations with chemotherapy and surgery, treatment volumes and planning, technological advances, and reradiation.

Epidemiology and Clinical Aspects of Malignant Pleural Mesothelioma

Mesothelioma is a cancer predominantly of the pleural cavity. There is a clear association of exposure to asbestos with a dose dependent risk of mesothelioma. The incidence of mesothelioma in different countries reflect the historical patterns of commercial asbestos utilisation in the last century and predominant occupational exposures mean that mesothelioma is mostly seen in males. Modern imaging techniques and advances in immunohistochemical staining have contributed to an improved diagnosis of mesothelioma. There have also been recent advances in immune checkpoint inhibition, however, mesothelioma remains very challenging to manage, especially considering its limited response to conventional systemic anticancer therapy and that no cure exists. Palliative interventions and support remain paramount with a median survival of 9-12 months after diagnosis. The epidemiology and diagnosis of mesothelioma has been debated over previous decades, due to a number of factors, such as the long latent period following asbestos exposure and disease occurrence, the different potencies of the various forms of asbestos used commercially, the occurrence of mesothelioma in the peritoneal cavity and its heterogeneous pathological and cytological appearances. This review will describe the contemporary knowledge on the epidemiology of mesothelioma and provide an overview of the best clinical practice including diagnostic approaches and management.

Pleural mesothelioma (PM) - The status of systemic therapy

Pleural mesothelioma (PM) remains a malignancy with poor prognosis. Despite initial disappointing response rates to single-agent chemotherapy, upfront platinum and anti-folate-based combination chemotherapy has remained the backbone of treatment for PM for the last three decades. The role of maintenance chemotherapy remains unclear; switch-maintenance gemcitabine has shown improvements in progression-free but not overall survival. The addition of antiangiogenic agents to chemotherapy yielded modest improvements in survival, both upfront in combination with platinum-pemetrexed, and in the relapsed setting. Immunotherapy, particularly PD-(L)1 inhibitors, has shown important but variable effectiveness in relapsed PM when used as monotherapy, and is an important salvage treatment after first-line chemotherapy. Furthermore, the randomized phase 3 trial of ipilimumab-nivolumab versus platinum-pemetrexed chemotherapy demonstrated improved overall survival favouring ipilimumab-nivolumab (HR 0.74, 96.6% CI 0.60-0.91; p = 0.0020), establishing this regimen as the new standard first-line treatment for PM, particularly in those with non-epithelioid histology. Increased interest in PM genomics has led to development of novel personalized therapeutics, such as those targeting DNA repair and EZH2 pathways, however with variable outcomes in trials. Targeting the membrane glycoprotein mesothelin and arginine deprivation are other important strategies under ongoing investigation. The field of PM is changing and new treatments bring hope to a largely lethal and poor prognostic malignancy. Despite these developments, current challenges include understanding the role of combination and multimodality treatments, drivers of resistance to treatment, and establishing predictive biomarkers to improve patient selection and treatment sequencing.

Implementing CT tumor volume and CT pleural thickness into future staging systems for malignant pleural mesothelioma

Objectives

Tumor thickness and tumor volume measured by computed tomography (CT) were suggested as valuable prognosticator for patients’ survival diagnosed with malignant pleural mesothelioma (MPM). The purpose was to assess the accuracy of CT scan based preoperatively measured tumor volume and thickness compared to actual tumor weight of resected MPM specimen and pathologically assessed tumor thickness, as well as an analysis of their impact on overall survival (OS).

Methods

Between 09/2013–08/2018, 74 patients were treated with induction chemotherapy followed by (extended) pleurectomy/decortication ((E)PD). In 53 patients, correlations were made between CT-measured volume and -tumor thickness (cTV and cTT) and actual tumor weight (pTW) based on the available values. Further cTV and pT/IMIG stage were correlated using Pearson correlation. Overall survival (OS) was calculated with Kaplan Meier analysis and tested with log rank test. For correlation with OS Kaplan-Meier curves were made and log rank test was performed for all measurements dichotomized at the median.

Results

Median pathological tumor volume (pTV) and pTW were 530 ml [130 ml – 1000 ml] and 485 mg [95 g – 982 g] respectively. Median (IQR) cTV was 77.2 ml (35.0–238.0), median cTT was 9.0 mm (6.2–13.7). Significant association was found between cTV and pTV (R = 0.47, p < 0.001) and between cTT and IMIG stage (p = 0,001) at univariate analysis. Multivariate regression analysis revealed, that only cTV correlates with pTV. Median follow-up time was 36.3 months with 30 patients dead at the time of the analysis. Median OS was 23.7 months. 1-year and 3-year survival were 90 and 26% respectively and only the cTV remained statistically associated with OS.

Conclusion

Preoperatively assessed CT tumor volume and actual tumor volume showed a significant correlation. CT tumor volume may predict pathological tumor volume as a reflection of tumor burden, which supports the integration of CT tumor volume into future staging systems.

Unusual case of malignant pleural mesothelioma

We present the case of a 65-year-old woman who presented with progressive dysphagia and was diagnosed with achalasia. She subsequently developed bilateral chylous pleural effusions, with no cause identified despite extensive investigations (including computed tomography (CT) scans, gastroscopy and medical thoracoscopy (MT)) and review at a dedicated pleural multidisciplinary team meeting.Despite optimal supportive management she deteriorated and was admitted to the intensive care unit, where she passed away due to sepsis and respiratory failure 10 months after initial presentation. A postmortem returned a diagnosis of epithelioid mesothelioma, encasing the carina, distal oesophagus and coeliac axis.Mesothelioma only very rarely presents with either chylous effusions or achalasia. Additionally while MT normally conveys excellent sensitivity for pleural malignancy, it was insufficient here. This case highlights how an unusually located mesothelioma can produce an unusual clinical picture. It also suggests a role for early video-assisted thoracoscopy to aid diagnosis.

Membranous HEG1 expression is a useful marker in the differential diagnosis of epithelioid and biphasic malignant mesothelioma versus carcinomas

Sialylated HEG1 has been reported as a highly specific and sensitive mesothelioma marker but a comprehensive evaluation of its expression in carcinomas in different organs, various sarcomas and reactive mesothelial proliferations has not been reported. The aim of this study was to evaluate the clinical applicability of HEG1 as a marker in the diagnosis of mesothelioma. HEG1 immunoreactivity was evaluated in whole sections of 122 mesotheliomas, 75 pulmonary carcinomas, 55 other carcinomas, 16 mesenchymal tumors, and 24 reactive mesothelial proliferations and in tissue microarrays containing 70 epithelioid (EM), 36 biphasic (BM), and 2 sarcomatoid mesotheliomas (SM). In whole sections and tissue microarrays, respectively, membranous HEG1 was expressed in 93.0% and 85.5% of EM, 81.3% and 69.4% of BM, 0% and 0% of SM. HEG1 was not expressed in pulmonary adenocarcinomas. HEG1 was expressed as cytoplasmic immunoreactivity in pulmonary squamous cell carcinomas (21.7%). Membranous HEG1 staining was seen in ovarian carcinomas (66.7%), thyroid carcinomas (100%), reactive conditions (16.7%), and mesenchymal tumors (18.8%). The sensitivity of membranous HEG1 expression to distinguish EM/BM from all carcinomas was 88.8%. The specificity for the differential diagnosis between EM/BM and all carcinomas and pulmonary carcinomas was 92.3% and 98.7%, respectively.

Ancillary Diagnostic Investigations in Malignant Pleural Mesothelioma

For a number of patients presenting with an undiagnosed pleural effusion, frailty, medical co-morbidity or personal choice may preclude the use of pleural biopsy, the gold standard investigation for diagnosis of malignant pleural mesothelioma (MPM). In this review article, we outline the most recent evidence on ancillary diagnostic tests which may be used to support a diagnosis of MPM where histological samples cannot be obtained or where results are non-diagnostic. Immunocytochemical markers, molecular techniques, diagnostic biomarkers and imaging techniques are discussed. No adjunctive test has a sensitivity and specificity profile to support use in isolation; however, correlation of pleural fluid cytology with relevant radiology and supplementary biomarkers can enable an MDT-consensus clinico-radiological-cytological diagnosis to be made where further invasive tests are not possible or not appropriate. Diagnostic challenges surrounding non-epithelioid MPM are recognised, and there is a critical need for reliable and non-invasive investigative tools in this population.

The minimum standard of care for managing malignant pleural mesothelioma in developing nations within the Asia-Pacific Region

Malignant pleural mesothelioma (MPM) is an incurable malignancy associated with high symptom burden and poor prognosis. The relationship between asbestos exposure and MPM incidence is well-established. The incidence rate of MPM in Australia and New Zealand is among the highest globally. Matching the experience of other nations with legal restrictions on asbestos, incidence is expected to fall. In contrast, the incidence of MPM is rising in the developing nations of the Asia-Pacific as consumption and mining (albeit to a lesser extent) of asbestos continues. The incidence of MPM in these nations is currently low or unknown, reflecting insufficient latency periods since industrial use of asbestos, deficient resources for accurate diagnosis, and lack of occupational disease or cancer registries. The landscape of treatment for MPM is rapidly changing with combination immunotherapy now demonstrating improved survival in the first-line setting. Considering vast global inequity in access to anticancer treatments, establishing minimum standard of care for MPM in developing nations is of greater significance. Here, we review the evidence that form the basis of our minimum-standard recommendations for diagnosis, systemic treatment, management of recurrent pleural effusions, and symptom management. We also briefly review evidence-based treatment that may be considered for those with access.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pretherapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasize that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Respiratory cytology in malignant lung disease - The thoracic oncologist's perspective

Respiratory cytology continues to play a central role in the diagnosis and staging of thoracic malignancy, although over time indications have changed. Historically, sputum cytology and endobronchial brushings and washings figured prominently, but with the advent of endobronchial and endoscopic ultrasound much greater emphasis is placed on fine needle aspirates from lymph nodes. The advent of targeted sequencing panels for genomic profiling to identify driver mutations and PD-L1 directed immunotherapy means that there is a need to extract increasing amounts of diagnostic and predictive information from ever smaller amounts of diagnostic material. Recent work has demonstrated that cytology samples are well suited to delivering the information required, but in order to understand the limitations of clinical and laboratory techniques, a close working relationship between pathologist and thoracic oncologist is needed to optimise sample procurement and utilisation.

The Association Between Pleural Fluid Exposure and Survival in Pleural Mesothelioma

BACKGROUND

Most patients with malignant pleural mesothelioma (MPM) seek treatment with malignant pleural effusion (MPE). In vitro evidence suggests that MPE may not be a simple bystander of malignancy, but rather potentially has biological properties that improve cancer cell survival and promote cancer progression. If this is the case, MPE management may need to shift from current symptomatic strategies to aggressive fluid removal to impact survival.

RESEARCH QUESTION

Is there an association between pleural fluid exposure and survival in MPM?

STUDY DESIGN AND METHODS

Data from 761 patients who received a diagnosis of MPM between 2008 and 2018 were collected from patient medical records in three UK pleural units. Data included factors previously identified as influencing prognosis in MPM. Medical imaging was reviewed for presence, size, and duration of pleural effusion. Time-dependent covariate analysis of pleural fluid exposure and survival (model included weight loss, serum albumin, hemoglobin, MPM subtype, performance status, chemotherapy, and age) and multivariate Cox regression analysis of pleurodesis and survival were conducted.

RESULTS

Median overall survival was 278 days (interquartile range, 127-505 days; 95% CI, 253-301 days). Pleural fluid exposure duration showed no association with survival (hazard ratio, 1.0; 95% CI, 1.0-1.0). Median survival was 473, 378, and 258 days with complete, partial, and no pleurodesis (P = .008).

INTERPRETATION

Pleurodesis success seems to be associated with improved survival; however, it is unclear whether duration of MPM exposure to pleural fluid is associated with survival within the limitations of this retrospective study. Future prospective studies are required to assess this potentially important mechanism.

Immune Checkpoint Inhibitor Uptake in Real-World Patients With Malignant Pleural Mesothelioma

INTRODUCTION

Since the July 2017 National Comprehensive Cancer Network (NCCN) malignant pleural mesothelioma (MPM) guideline revision recommended second-line immune checkpoint inhibitors (ICIs), studies have suggested a greater response to ICI among patients with nonepithelioid MPM. Nevertheless, little is known regarding adoption of ICI in routine practice and if uptake differs by histologic subtype. Our objectives were to evaluate the real-world uptake of second-line ICI among patients with MPM and to reveal its association with histologic subtype.

METHODS

This was a multicenter, retrospective cohort study of real-world patients with MPM receiving at least two lines of systemic therapy between 2011 and 2019. We found the uptake of second-line ICI over time and evaluated the association between histologic subtype and ICI use, adjusting for relevant patient demographic and clinical factors.

RESULTS

Among the 426 patients with MPM in our cohort, 310 had epithelioid and 116 nonepithelioid histologic subtype. The median age was 73 years (interquartile range: 67-78). Overall, 144 patients (33.8%) received second-line ICI and 282 (66.2%) traditional chemotherapy. ICI uptake began in early 2015 before the NCCN guideline revision and increased rapidly to 2019. After the 2017 NCCN guideline revision, patients with nonepithelioid MPM histologic subtypes had more than 3 times the odds of receiving second-line ICI (OR = 3.26; 95% confidence interval: 1.41-7.54).

CONCLUSIONS

Among real-world patients with MPM, second-line ICI uptake began over two years before the 2017 NCCN guideline recommendations and was associated with nonepithelioid histologic subtype after contemporary studies suggested increased clinical benefit in this population, reflecting prompt integration of scientific discovery into clinical practice.

When the Diagnosis of Mesothelioma Challenges Textbooks and Guidelines

The diagnosis of malignant mesothelioma (MPM) does not pose difficulties when presenting with usual clinico-radiologic features and morphology. Pathology textbooks and national/international guidelines generally describe the findings of classic MPM, underlining common clinical presentation, the gold standard of sampling techniques, usual morphologic variants, immunohistochemical results of several positive and negative primary antibodies in the differential diagnosis, and the role of novel molecular markers. Nevertheless, MPM often does not follow the golden rules in routine practice, while the literature generally does not sufficiently emphasize unusual features of its manifestation. This gap may potentially create problems for patients in sustaining a difficult diagnosis of MPM in clinical practice and during legal disputes. Indeed, the guidelines accidentally tend to favor the job of lawyers and pathologists defending asbestos-producing industries against patients suffering from MPM characterized by uncommon features. The current review is aimed at underlining the wide spectrum of clinical and radiological presentation of MPM, the possibility to consistently use cytology for diagnostic intent, the aberrant immunohistochemical expression using so-called specific negative and positive primary antibodies, and finally proposing some alternative and more unbiased approaches to the diagnosis of MPM.

Malignant pleural mesothelioma: Comparison of surgery-based trimodality therapy to medical therapy at two tertiary academic institutions

OBJECTIVES

Medical management based on palliative chemotherapy is currently the standard of care in malignant pleural mesothelioma (MPM). Median survival of 12-16 months has been reported with modern chemotherapy regimens with or without anti-angiogenic agents. Multimodality therapy incorporating cytoreductive surgery, systemic chemotherapy and radiotherapy has been offered for years to fit patients with early-stage disease, but its role remains debated. Our objective was to compare overall survival in patients offered multimodality therapy in a specialized clinic setting in London, UK to that of patients offered exclusively medical treatment at another academic institution in Quebec, Canada.

MATERIALS AND METHODS

We retrospectively compared the survival rates of 2 separate cohorts of patients treated consecutively: Cohort 1 (n = 106) received multimodality therapy including systemic chemotherapy, extended pleurectomy/decortication (P/D) and prophylactic radiotherapy in London (United Kingdom) between 2009 and 2016, while Cohort 2 (n = 98) received medical treatment at the Quebec Heart and Lung Institute (Canada) during the same period.

RESULTS

In Cohort 1, all patients but two completed trimodality therapy. In cohort 2, 51 % received palliative care only and 40 % received systemic chemotherapy. Median survival was 32 months vs 10 months in Cohort 1 and Cohort 2, respectively (hazard ratio with age, gender, pathology and TNM staging as covariates: 3.81; 95 % CI: 2.67-5.45; p < 0.0001). Similar results were obtained in sensitivity analyses, after excluding those who received best supportive care only and in a propensity score-matched analysis.

CONCLUSION

Aggressive therapy of MPM using cancer-directed surgery, systemic chemotherapy and prophylactic radiotherapy may provide a significant survival benefit in selected patients.

Pleural Fluid Has Pro-Growth Biological Properties Which Enable Cancer Cell Proliferation

Objectives

Patients with malignant pleural mesothelioma (MPM) or pleural metastases often present with malignant pleural effusion (MPE). This study aimed to analyze the effect of pleural fluid on cancer cells.

Materials and Methods

Established patient-derived cancer cell cultures derived from MPE (MPM, breast carcinoma, lung adenocarcinoma) were seeded in 100% pleural fluid (exudate MPM MPE, transudate MPE, non-MPE transudate fluid) and proliferation was monitored. In addition, the establishment of new MPM cell cultures, derived from MPE specimens, was attempted by seeding the cells in 100% MPE fluid.

Results

All established cancer cell cultures proliferated with similar growth rates in the different types of pleural fluid. Primary MPM cell culture success was similar with MPE fluid as with full culture medium.

Conclusions

Pleural fluid alone is adequate for cancer cell proliferation in vitro, regardless of the source of pleural fluid. These results support the hypothesis that pleural fluid has important pro-growth biological properties, but the mechanisms for this effect are unclear and likely not malignant effusion specific.

Tract metastasis in patients with long-term pleural catheter-computed tomography diagnosis and longitudinal assessment

OBJECTIVES

Long-term indwelling pleural catheters (IPC), used for the management of malignant pleural mesothelioma (MPM), may lead to catheter tract metastasis (CTM). While computed tomography (CT) is valuable for diagnosis, no studies have assessed CT manifestations of CTM. Our goal is to describe the incidence, CT appearances, and temporal evolution of CTM in MPM.

METHODS

A retrospective review of CT of 90 consecutive patients with MPM and IPC. In patients with CTM, a longitudinal assessment was performed for CT appearance at diagnosis and over time, interval from insertion to diagnosis and rate of progression.

RESULTS

The incidence of CTM was 26% (23/90), in 22 men (54-83 years, mean 73 years). CTM manifested with focal lesion (3 to 60 mm, mean 25 mm) in the subcutaneous tissue at the insertion site. Abnormalities of sub-adjacent skin and fat stranding were present in 16/24 (66%) and 11/24 (46%), respectively, enlargement of chest wall musculature in 11/24 (46%), and dilated subcutaneous vessels in 4/24 (17%) patients. On follow-up, 53% had enlargement of focal lesion. The average rate of progression was 3.5 mm/month, compared to 0.79 mm/month for pleural thickening (p = 0.03). The time between IPC insertion and CTM diagnosis varied from 58 to 1375 days (median 408 days); 83% occurred after IPC removal. Reporting radiologists described focal abnormality at the insertion site in only 9/23 (39%) patients.

CONCLUSIONS

CTM is commonly overlooked and underreported by radiologists. CT invariably demonstrates focal subcutaneous lesion in the procedure tract, most commonly after IPC removal. Ancillary findings, notably serratus or latissimus dorsi muscle enlargement, are novel finding that can assist in CT detection and diagnosis.

KEY POINTS

• Catheter tract metastasis (CTM), resulting from indwelling pleural catheter to manage malignant pleural mesothelioma, invariably manifested on CT as a focal subcutaneous lesion at the site of insertion, more commonly after catheter removal. • Ipsilateral muscle enlargement is a newly described CT finding that can assist in the detection and diagnosis. • Catheter tract metastasis was commonly overlooked by radiologists, reported in only 39% of cases.

Accuracy of pleural biopsy for the diagnosis of histologic subtype of malignant pleural mesothelioma: Necropsy-based study of 134 cases

BACKGROUND

Definition of histologic subtype of malignant pleural mesothelioma (MPM) is important for management of patients, because surgical treatment improves prognosis for patients with epithelioid but not biphasic or sarcomatoid MPM. In a series of necropsies performed in a hospital specialized for MPM diagnosis, we retrospectively investigated the accuracy of histologic diagnosis performed on pathologic specimens collected through pleural biopsies obtained at video-assisted thoracoscopic surgery (VATS) or surgery.

METHODS

We reviewed histologic records of an unselected series of autopsies performed in patients with MPM employed in the Monfalcone shipyards (Northeast Italy) or living with shipyard workers from 1999 through 2017. Using necropsy results as a gold standard, we calculated sensitivity, specificity, and positive and negative predictive values of histology from VATS or surgery after combining nonepithelioid subtypes.

RESULTS

We retrieved necropsy records for 134 patients: 62 (46.3%) with epithelioid, 51 (38.1%) with biphasic, and 21 (15.7%) with sarcomatoid MPM. We observed good sensitivity of VATS (0.94) and surgery (0.89) in diagnosing epithelioid MPM. Conversely, specificity was low (VATS: 0.46; surgery: 0.32). Therefore, positive predictive values were also low (VATS: 0.58; surgery: 0.60). Misclassification was particularly high for biphasic MPM (three-fourths of biphasic MPM at necropsy had been classified as epithelioid at VATS or surgery).

CONCLUSIONS

We observed a substantial degree of misclassification between epithelioid and biphasic MPM for pleural biopsies performed during VATS. Our results suggest caution should be taken in using histologic subtype obtained from VATS in selecting patients with MPM for surgical treatment. We also observed substantial misclassification of biospecimens collected during MPM surgery.

Pleural biomarkers in diagnostics of malignant pleural effusion: a narrative review

Although cytology and pleural biopsy of pleural effusion (PE) are the gold standards for diagnosing malignant pleural effusion (MPE), these tools’ diagnostic accuracy is plagued by some limitations such as low sensitivity, considerable inter-observer variation and invasiveness. The assessment of PE biomarkers may hence be seen as an objective and non-invasive diagnostic alternative in MPE diagnostics. In this review, we summarize the characteristics and diagnostic accuracy of available PE biomarkers, including carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), carbohydrate antigens 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 15-3 (CA15-3), a fragment of cytokeratin 19 (CYFRA 21-1), chitinase-like proteins (CLPs), vascular endothelial growth factor (VEGF) and its soluble receptor, endostatin, calprotectin, cancer ratio, homocysteine, apolipoprotein E (Apo-E), B7 family members, matrix metalloproteinase (MMPs) and tissue-specific inhibitors of metalloproteinases (TIMPs), reactive oxygen species modulator 1 (Romo1), tumor-associated macrophages (TAMs) and monocytes, epigenetic markers (e.g., cell-free microRNA and mRNA). We summarized the evidence from systematic review and meta-analysis for traditional tumor markers’ diagnostic accuracy. According to the currently available evidence, we conclude that the traditional tumor markers have high specificity (around 0.90) but low sensitivity (around 0.50). The diagnostic accuracy of novel tumor markers needs to be validated by further studies. None of these tumor biomarkers would have sufficient diagnostic accuracy to confirm or exclude MPE when used alone. A multi-biomarker strategy, also encompassing the use of artificial intelligence algorithms, may be a valuable perspective for improving the diagnostic accuracy of MPE.

Preoperative Identification of Benefit from Surgery for Malignant Pleural Mesothelioma

In the absence of standardized treatment algorithms for patients with malignant pleural mesothelioma, one of the main difficulties remains patient allocation to therapies with potential benefit. This article discusses clinical, radiologic, pathologic, and molecular prognostic factors as well as genetic background leading to preoperative identification of benefit from surgery, which have been investigated over the past years to simplify and at the same time specify patient selection for surgical treatment.

Recommendations for improving follow-up care for patients with mesothelioma: a qualitative study comprising documentary analysis, interviews and consultation meetings

OBJECTIVES

The study aim was to explore experiences of patients with pleural mesothelioma of follow-up care in three National Health Service (NHS) Trusts to develop recommendations for practice.

DESIGN

The study design was qualitative and comprised three interlinked phases: a documentary analysis, interviews and consultation meetings. Altheide and Johnson's Analytic Realism theoretical framework guided the thematic data analysis process.

SETTING

The study was conducted in three NHS Trusts in South England. Two were secondary care settings and the third was a tertiary centre.

PARTICIPANTS

The secondary care trusts saw 15-20 patients with new mesothelioma per year and the tertiary centre 30-40. The tertiary centre had a designated mesothelioma team. Twenty-one patients met the inclusion criteria: >18 years, mesothelioma diagnosis and in follow-up care. Non-English speaking participants, those unable to provide written informed consent or those whom the clinical team felt would find participation too distressing were excluded. All participants were white, 71% were 70-79 years old and 71% were men. Three consultation meetings were conducted with key stakeholders including mesothelioma nurse specialists, patients with mesothelioma, carers and local clinical commissioning group members.

MAIN OUTCOME MEASURES

Specific outcomes were to gain a detailed understanding of mesothelioma follow-up care pathways and processes and to develop coproduced recommendations for practice.

RESULTS

Mesothelioma pathways were not always distinct from lung cancer care pathways. All trusts provided follow-up information and resources but there was varied information on how to access local support groups, research or clinical trial participation. Five themes were developed relating to people; processes; places; purpose and perception of care. Coproduced recommendations for improving mesothelioma follow-up pathways were developed following the consultation meetings.

CONCLUSIONS

This study has developed recommendations which identify the need for patients with pleural mesothelioma to access consistent, specialist, streamlined mesothelioma care, centred around specialist mesothelioma nurses and respiratory consultants, with input from the wider multidisciplinary team.

Update on biology and management of mesothelioma

Malignant pleural mesothelioma is an aggressive, incurable cancer that is usually caused by asbestos exposure several decades before symptoms arise. Despite widespread prohibition of asbestos production and supply, its incidence continues to increase. It is heterogeneous in its presentation and behaviour, and diagnosis can be notoriously difficult. Identification of actionable gene mutations has proven challenging and current treatment options are largely ineffective, with a median survival of 10-12 months.However, the past few years have witnessed major advances in our understanding of the biology and pathogenesis of mesothelioma. This has also revealed the limitations of existing diagnostic algorithms and identified new treatment targets.Recent clinical trials have re-examined the role of surgery, provided new options for the management of associated pleural effusions and heralded the addition of targeted therapies. The increasing complexity of mesothelioma management, along with a desperate need for further research, means that a multidisciplinary team framework is essential for the delivery of contemporary mesothelioma care.This review provides a synthesised overview of the current state of knowledge and an update on the latest research in the field.

Diagnostic mesothelioma biomarkers in effusion cytology

Malignant mesothelioma is a rare malignancy with a poor prognosis whose development is related to asbestos fiber exposure. An increasing role of genetic predisposition has been recognized recently. Pleural biopsy is the gold standard for diagnosis, in which the identification of pleural invasion by atypical mesothelial cell is a major criterion. Pleural effusion is usually the first sign of disease; therefore, a cytological specimen is often the initial or the only specimen available for diagnosis. Given that reactive mesothelial cells may show marked atypia, the diagnosis of mesothelioma on cytomorphology alone is challenging. Accordingly, cell block preparation is encouraged, as it permits immunohistochemical staining. Traditional markers of mesothelioma such as glucose transporter 1 (GLUT1) and insulin-like growth factor 2 mRNA-binding protein 3 (IMP3) are informative, but difficult to interpret when reactive proliferations aberrantly stain positive. BRCA1-associated protein 1 (BAP1) nuclear staining loss is highly specific for mesothelioma, but sensitivity is low in sarcomatoid tumors. Cyclin-dependent kinase inhibitor 2A (CDKN2A)/p16 homozygous deletion, assessed by fluorescence in situ hybridization, is more specific for mesothelioma with better sensitivity, even in the sarcomatoid variant. The surrogate marker methylthioadenosine phosphorylase (MTAP) has been found to demonstrate excellent diagnostic correlation with p16. The purpose of this review is to provide an essential appraisal of the literature regarding the diagnostic value of many of these emerging biomarkers for malignant mesothelioma in effusion cytology.

Predicting survival in malignant pleural mesothelioma using routine clinical and laboratory characteristics

INTRODUCTION

The prognosis of malignant pleural mesothelioma (MPM) is poor, with a median survival of 8-12 months. The ability to predict prognosis in MPM would help clinicians to make informed decisions regarding treatment and identify appropriate research opportunities for patients. The aims of this study were to examine associations between clinical and pathological information gathered during routine care, and prognosis of patients with MPM, and to develop a 6-month mortality risk prediction model.

METHODS

A retrospective cohort study of patients diagnosed with MPM at Queen Alexandra Hospital, Portsmouth, UK between December 2009 and September 2013. Multivariate analysis was performed on routinely available histological, clinical and laboratory data to assess the association between different factors and 6-month survival, with significant associations used to create a model to predict the risk of death within 6 months of diagnosis with MPM.

RESULTS

100 patients were included in the analysis. Variables significantly associated with patient survival in multivariate analysis were age (HR 1.31, 95% CI 1.09 to 1.56), smoking status (current smoker HR 3.42, 95% CI 1.11 to 4.20), chest pain (HR 2.14, 95% CI 1.23 to 3.72), weight loss (HR 2.13, 95% CI 1.18 to 3.72), platelet count (HR 1.05, 95% CI 1.00 to 1.10), urea (HR 2.73, 95% CI 1.31 to 5.69) and adjusted calcium (HR 1.47, 95% CI 1.10 to 1.94). The resulting risk model had a c-statistic value of 0.76. A Hosmer-Lemeshow test confirmed good calibration of the model against the original dataset.

CONCLUSION

Risk of death at 6 months in patients with a confirmed diagnosis of MPM can be predicted using variables readily available in clinical practice. The risk prediction model we have developed may be used to influence treatment decisions in patients with MPM. Further validation of the model requires evaluation of its performance on a separate dataset.

Role of Cytology in the Current Guidelines for Malignant Mesothelioma: Largest Study from India

INTRODUCTION

Cytology provides crucial window for early diagnosis of malignant mesothelioma (MM) since it is often the first and easily available material for evaluation, resulting in early treatment. Still, its role is overlooked in the current treatment guidelines. The aim of this study is to determine the sensitivity of cytomorphology and role of subsequent ancillary techniques in diagnosing MM.

METHODS

This is a 5-year retrospective analysis of MM in the tertiary oncology center to determine sensitivity of cytomorphology and subsequent role of immunohistochemistry (IHC) in final diagnosis of MM according to the guidelines for cytopathologic diagnosis of epithelioid and mixed-type malignant mesothelioma (GCDMM) laid by International Mesothelioma Interest Group. Cytomorphology and immunocytochemistry from effusions and fine needle aspirations were analyzed.

RESULTS

Sixty-two of 128 cases of MM had cytology and cytomorphological criteria described in GCDMM were fulfilled in 61.3% cases. Architectural atypia was useful in identifying cases with low cytological atypia. Overall sensitivity of cytomorphology was 73.01%. Sensitivity of effusion cytology was 77.8%. Subsequent IHC on cell blocks revealed the sensitivity as 100% for mesothelin, calretinin, and cytokeratin 5/6; 87.5% for thrombomodulin; and 50% for WT1, while CEA and TTF1 showed 100% specificity. Treatment was given based on final diagnosis of MM given after IHC on cytology material in only 25.8% cases. However, it was possible in additional 35.5% cases. Mean survival was 10 months when diagnosed by cytology, compared to 7 months by histology.

CONCLUSIONS

Rather than ignoring the role of cytology in the diagnosis and treatment guidelines for MM, it is important to understand its strengths and limitations. Standardized guidelines in future can play an important role in more streamlined communication between cytopathologist and clinician.

A review of malignant pleural mesothelioma in a large North East UK pleural centre

Objectives

The National Mesothelioma Audit 2020 showed Northumbria to have low rates of histopathological confirmation, treatment and one-year survival rates for malignant pleural mesothelioma (MPM). We hypothesized that an internal analysis over a 10-year period provides valuable insights into presentation, diagnosis, treatment and outcomes.

Methods

A single-centre retrospective case series of all confirmed MPM patients between 1 January 2009 and 31 December 2019 was performed. Demographics, clinical, radiological and histopathological characteristics and outcomes were collected. Statistical analysis was performed using SPSS V26.0.

Results

A total of 247 patients had MPM. About 86% were male, mean age 75.7 years. Dyspnoea (77.4%) and chest pain (38.5%) were commonest symptoms. 64.9 and 71.4% had pleural thickening and effusion, respectively. About 86.8% had at least one attempt to obtain a tissue biopsy, but histopathological confirmation in only 108 (43.7%). About 66.3% with PS 0 and 1 (62.7% of total cohort) had at least one anti-cancer therapy. Death within 12 months was associated with disease progression within 6 months (p≤0.001). Chemotherapy (p≤0.001) and epithelioid histological subtype (p=0.01) were protective.

Conclusions

This study confirms known epidemiology of MPM, demonstrates variability in practices and highlights how some NMA recommendations are not met. This provides the incentive for a regional mesothelioma multi-disciplinary meeting.

A comparison between MRI and CT in the assessment of primary tumour volume in mesothelioma

INTRODUCTION

Primary tumour staging in Malignant Pleural Mesothelioma (MPM) using Computed Tomography (CT) imaging is confounded by perception errors reflecting low spatial resolution between tumour and adjacent structures. Augmentation using perfusion CT is constrained by radiation dosage. In this study, we evaluated an alternative tumour staging method using perfusion-tuned Magnetic Resonance Imaging (MRI).

METHODS

Consecutive patients with suspected MPM were recruited to a prospective observational study. All had MRI (T1-weighted, isotropic, contrast-enhanced 3-Tesla perfusion imaging) and CT (contrast-enhanced) pre-biopsy. Patients diagnosed with MPM underwent MRI and CT volumetry, with readers blinded to clinical data. MRI volumetry was semi-automated, using signal intensity limits from perfusion studies to grow tumour regions within a pleural volume. A similar CT method was not possible, therefore all visible tumour was manually segmented. MRI and CT volumes were compared (agreement, correlation, analysis time, reproducibility) and associations with survival examined using Cox regression.

RESULTS

58 patients were recruited and had MRI before biopsy. 31/58 were diagnosed with MPM and these scans were used for volumetry. Mean (SD) MRI and CT volumes were 370 cm3 and 302 cm3, respectively. MRI volumes were larger (average bias 61.9 cm3 (SD 116), 95 % limits (-165.5 - 289 cm3), moderately correlated with CT (r = 0.56, p = 0.002) and independently associated with survival (HR 4.03 (95 % CI 1.5-11.55), p = 0.006). CT volumes were not associated with survival, took longer to compute than MRI volumes (mean (SD) 151 (19) v 14 (2) minutes, p=<0.0001) and were less reproducible (inter-observer ICC 0.72 for CT, 0.96 for MRI).

CONCLUSIONS

MRI and CT generate different tumour volumes in MPM. In this study, MRI volumes were larger and were independently associated with survival. MRI volumetry was quicker and more reproducible than CT.

Diagnostic value of microRNAs for malignant pleural mesothelioma: A mini-review

Malignant pleural mesothelioma (MPM) is a type of cancer originating from the pleura with high aggressiveness and poor prognosis. A timely diagnosis is crucial to improve its prognosis. Laboratory biomarkers have significant advantages of reduced invasiveness, low cost, and are observer‐independent, and therefore represent a promising diagnostic tool for MPM. MicroRNA is a family of non‐coding RNA that regulates gene expression at the post‐transcriptional level. Accumulated studies showed that microRNA, either in tissue, circulating, and body fluid, has potential diagnostic value for various disorders. Here, we reviewed the diagnostic value of microRNA for MPM.

Laser ablation inductively coupled plasma mass spectrometry as a novel clinical imaging tool to detect asbestos fibres in malignant mesothelioma

RATIONALE

Malignant pleural mesothelioma is an extremely aggressive and incurable malignancy associated with prior exposure to asbestos fibres. Difficulties remain in relation to early diagnosis, notably due to impeded identification of asbestos in lung tissue. This study describes a novel laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) imaging approach to identify asbestos within mesothelioma models with clinical significance.

METHODS

Human mesothelioma cells were exposed to different types of asbestos fibres and prepared on plastic slides for LA-ICP-MS analysis. No further sample preparation was required prior to analysis, which was performed using an NWR Image 266 nm laser ablation system coupled to an Element XR sector-field ICP mass spectrometer, with a lateral resolution of 2 μm. Data was processed using LA-ICP-MS ImageTool v1.7 with the final graphic production made using DPlot software.

RESULTS

Four different mineral fibres were successfully identified within the mesothelioma samples based on some of the most abundant elements that make up these fibres (Si, Mg and Fe). Using LA-ICP-MS as an imaging tool provided information on the spatial distribution of the fibres at cellular level, which is essential in asbestos detection within tissue samples. Based on the metal counts generated by the different types of asbestos, different fibres can be identified based on shape, size, and elemental composition. Detection of Ca was attempted but requires further optimisation.

CONCLUSIONS

Detection of asbestos fibres in lung tissues is very useful, if not necessary, to complete the pathological dt9iagnosis of asbestos-related malignancies in the medicolegal field. For the first time, this study demonstrates the successful application of LA-ICP-MS imaging to identify asbestos fibres and other mineral fibres within mesothelioma samples. Ultimately, high-resolution, fast-speed LA-ICP-MS analysis has the potential to be integrated into clinical workflow to aid earlier detection and stratification of mesothelioma patient samples.

Standards of care in mesothelioma treatment

The UK has the highest incidence of mesothelioma in the world, but services vary across the country partly due to uneven geographical distribution of cases. The Mesothelioma UK-funded national organisational audit has highlighted challenges in accessing diagnostic procedures such as thoracoscopy, as well as identifying examples of best practice, including access to clinical trials and specialist therapeutic procedures. To ensure equitable and optimal patient care, cancer alliances should have established referral pathways to specialist multidisciplinary team (MDT) services for discussion of all mesothelioma patients.

Malignant Pleural Effusion: Diagnosis and Management

Symptomatic malignant pleural effusion is a common clinical problem. This condition is associated with very high mortality, with life expectancy ranging from 3 to 12 months. Studies are contributing evidence on an increasing number of therapeutic options (therapeutic thoracentesis, thoracoscopic pleurodesis or thoracic drainage, indwelling pleural catheter, surgery, or a combination of these therapies). Despite the availability of therapies, the management of malignant pleural effusion is challenging and is mainly focused on the relief of symptoms. The therapy to be administered needs to be designed on a case-by-case basis considering patient's preferences, life expectancy, tumour type, presence of a trapped lung, resources available, and experience of the treating team. At present, the management of malignant pleural effusion has evolved towards less invasive approaches based on ambulatory care. This approach spares the patient the discomfort caused by more invasive interventions and reduces the economic burden of the disease. A review was performed of the diagnosis and the different approaches to the management of malignant pleural effusion, with special emphasis on their indications, usefulness, cost-effectiveness, and complications. Further research is needed to shed light on the current matters of controversy and help establish a standardized, more effective management of this clinical problem.

Patient-derived malignant pleural mesothelioma cell cultures: a tool to advance biomarker-driven treatments

Malignant pleural mesothelioma (MPM) is an aggressive cancer, associated with poor prognosis. We assessed the feasibility of patient-derived cell cultures to serve as an ex vivo model of MPM. Patient-derived MPM cell cultures (n=16) exhibited stemness features and reflected intratumour and interpatient heterogeneity. A subset of the cells were subjected to high-throughput drug screening and coculture assays with cancer-specific cytotoxic T cells and showed diverse responses. Some of the biphasic MPM cells were capable of processing and presenting the neoantigen SSX-2 endogenously. In conclusion, patient-derived MPM cell cultures are a promising and faithful ex vivo model of MPM.

Diffuse pleural thickening and thoracic contraction: An indistinguishable case from malignant pleural mesothelioma

The differential diagnosis of reactive mesothelial hyperplasia and mesothelioma is difficult. We present a rare case of diffuse pleural thickening with thoracic contraction that was indistinguishable from mesothelioma. A 66-year-old woman with no history of asbestos exposure visited our hospital with a complaint of dyspnea. The clinical findings included circumferential pleural thickening on chest computed tomography image and a high concentration of hyaluronic acid in the pleural fluid. Pleural biopsies obtained by thoracoscopy under local anesthesia were pathologically consistent with mesothelioma, but the patient refused to take any kind of mesothelioma treatments. Four months later, she consented to a surgical pleural biopsy under general anesthesia to obtain larger tissue samples, which included typical proliferating polygonal cells positive for CAM5.2, calretinin, WT-1, D2-40, CK5/6, epithelial membrane antigen, and glucose transporter-1 and negative for carcinoembryonic antigen, BerEP4, and MOC31. The analysis was consistent with diagnosis of epithelioid mesothelioma. Fluorescence in situ hybridization, however, showed the presence of p16 gene, and the expression of BRCA1-associated protein-1 was detected by immunohistochemistry. Our final diagnosis was diffuse pleural thickening unrelated to asbestos exposure. Differential diagnosis of diffuse pleural thickening and malignant mesothelioma is thus difficult and routine immunohistochemical examinations are often insufficient for accurate diagnosis. Multiple diagnostic methods are required for correct diagnosis in a clinically marginal case.

Medical thoracoscopy in the diagnosis of pleural disease: a guide for the clinician

INTRODUCTION

Developing a feasible and accurate means of evaluating pleural pathology has been an ongoing effort for over 150 years. Pleural fluid cellular and biomarker analyses are simple ways of characterizing and uncovering pathologic entities of pleural disease. However, obtaining samples of pleural tissue has become increasingly important. In cases of suspected malignancy and certain infections histopathology, culture, and molecular testing are necessary to profile diseases more effectively. The pleura is sampled via several techniques including blind transthoracic biopsy, image-guided biopsy, and surgical thoracotomy. Given the heterogeneity of pleural disease, low diagnostic yields, or invasiveness no procedural gold standard has been established in pleural diagnostics.

AREAS COVERED

Herein, we provide a review of the literature on medical thoracoscopy (MT), its development, technical approach, indications, risks, current and future role in the evaluation of thoracic disease. Pubmed was searched for articles published on MT, awake thoracoscopy, and pleuroscopy with a focus on reviewing literature published in the past 5 years.

EXPERT OPINION

As the proficiency and number of interventional pulmonologists continues to grow, MT is ideally positioned to become a front-line diagnostic tool in pleural disease and play an increasingly prominent role in the treatment algorithm of various pleural pathologies.

Postoperative complications of pulmonary resection

Thoracic surgery has seen a resurgence in recent years with increasing numbers of cases taken on since the mid-2000s. There has been a paradigm shift in how we manage lung cancer with more emphasis on surgical resection, and this has been aided by minimally invasive video-assisted thoracic surgery (VATS) techniques. As a result, the prevalence of postoperative findings and complications is also increasing, and it is increasingly important for the general radiologist to recognise and diagnose these conditions as thoracic surgical patients may present acutely to non-thoracic surgical institutions. This review will cover both the early and late complications following a variety of lung resection surgeries.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pre-therapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Investigation of a unilateral pleural effusion: What CT scan coverage is optimal?

The use of thoracic CT for patients presenting with a unilateral pleural effusion is well established. However, there is no consensus with regard to the inclusion of the entire abdomen and pelvis in the initial imaging protocol. In this prospective UK-based study, 249 patients presenting with a unilateral effusion had a CT thorax/abdomen/pelvis performed. The prevalence of malignancy on thoracic CT was 56% (140/249). Clinically significant findings below the diaphragm were identified in 59 patients (24%). Integrating this approach into standard practice allows more rapid identification of the primary malignancy, upstaging lesions or alternative sites for biopsy.

Clinical Features in Patients With Malignant Pleural Mesothelioma With 5-Year Survival and Evaluation of Original Diagnoses

INTRODUCTION

Malignant pleural mesothelioma (MPM) is a fatal malignancy strongly associated with previous asbestos exposure. Overall survival remains dismal, partly owing to poor response to available treatment. The aims of this study were to evaluate diagnostic accuracy in a group of patients with MPM with an unusually long survival time and to assess the factors related to this prolonged survival.

MATERIALS AND METHODS

Forty-three patients with overall survival exceeding 5 years were accepted to the long-term survivor (LTS) group, and these patients were compared with 84 patients with epithelial MPM. Data were collected from various national registries and electronic medical records. In addition, all available histopathologic diagnostic samples and computed tomography studies were re-evaluated by experienced specialists.

RESULTS

Our study showed a good diagnostic accuracy, with only 1 (0.5%) patient having an incorrect MPM diagnosis. Two (0.9%) localized malignant mesotheliomas and 2 (0.9%) well-differentiated papillary mesotheliomas were also found. LTS patients were younger, more frequently female, had a better performance status at time of diagnosis, and had less evidence of prior asbestos exposure. In multivariate analysis, we showed tumor size, Eastern Cooperative Oncology Group performance status, and first-line treatment (both surgery and chemotherapy) to be associated with survival time.

CONCLUSION

We confirmed the diagnosis of MPM in an overwhelming majority of patients in the LTS group. An epithelial subtype of MPM behaving clinically more indolently seems to exist, but further tumor and genetic characterization is needed. The prolonged survival time is most likely explained by a combination of tumor-, patient-, and treatment-related factors.

HEG1, BAP1, and MTAP are useful in cytologic diagnosis of malignant mesothelioma with effusion

BACKGROUND

The specificity and sensitivity of HEG1 for malignant mesothelioma (MM) is high. The use of BAP1/MTAP immunohistochemistry (IHC) is recommended to separate benign and malignant mesothelial proliferations. We determined how ancillary techniques can be used for the cytological diagnosis of MM with effusion.

METHODS

Cell blocks from effusions from cases with MM, reactive mesothelial cells (RMCs), and carcinomas were analyzed by IHC with HEG1, BAP1, and MTAP and with homozygous deletion (HD) of CDKN2A by fluorescence in situ hybridization. Staining scores were calculated for IHC by adding the number of categories for the staining intensity and the staining extension.

RESULTS

HEG1 was positive in all (41/41) MMs, but negative in carcinomas, except for ovarian carcinomas. Overall 76.9% (20/26) of RMCs and 28.6% (6/21) of ovarian carcinomas expressed HEG1. BAP1 loss was found in 71.1% of MMs, but none was found in RMCs. MTAP loss was found in 76.2% of MMs, but none was found in RMCs. 73.9% of MMs harbored HD of CDKN2A. There was concordance between loss of MTAP and HD of CDKN2A in 95% of MMs.

CONCLUSION

HEG1 is a good marker for mesothelial differentiation in effusion cytology. HD of CDKN2A is frequently observed in cell blocks from effusions of MMs, and MTAP IHC may act as a surrogate for HD of CDKN2A. Cell block analysis is recommended for effusions of unknown origins with the following methods: IHC with HEG1 and claudin 4 to validate the mesothelial origin, followed by BAP1 and MTAP IHC to confirm malignancy.

Clinical Trials Eligibility of Patients With Malignant Pleural Mesothelioma: Use of Novel Therapies and Outcomes

INTRODUCTION

Studies of bevacizumab and pembrolizumab in the treatment of malignant pleural mesothelioma suggest anticancer efficacy; clinical trial populations are not reflective of real-world patients. We aimed to determine the proportion of real-world patients who would be eligible for trials, identify patients who participated in clinical trials, and examine treatment and outcome data.

PATIENTS AND METHODS

Consecutive patients with unresectable malignant pleural mesothelioma seen at our center from January 2012 to July 2018 were assessed with regards to their eligibility for Mesothelioma Avastin Cisplatin Study (MAPS) and KEYNOTE-028 clinical trials. Prognostic information, treatment use, and overall survival (OS) data were also collected.

RESULTS

A total of 133 patients were included: 50% and 37%, respectively, did not meet trial eligibility for MAPS or KEYNOTE-028, most commonly owing to age ≥75 (23%), Eastern Cooperative Oncology Group performance status of ≥2 (21%), concomitant medication (21%), or comorbidity (12%). MAPS eligibility did not correlate with use of bevacizumab (P = .30) or improved OS (P = .87). Eligibility for KEYNOTE-028 correlated with pembrolizumab use (P < .001), but not improved OS (P = .21). Patients who received an investigational anticancer therapy on any clinical trial had improved OS: 32.4 (95% CI, 23.9-40.9) months versus 20.5 (95% CI, 15.8-25.3) months (P = .01).

CONCLUSION

Only ≤63% of our patients were eligible for these trials, highlighting the differences between real-world patients and the highly select trial population. Our patients who participated in clinical trials had superior OS, further emphasizing the selection bias in the trial population.

The role of imaging in malignant pleural mesothelioma: an update after the 2018 BTS guidelines

Malignant pleural mesothelioma (MPM) is a primary malignancy of the pleura and is associated with a poor outcome. The symptoms and signs of malignant mesothelioma present late in the natural history of the disease and are non-specific, making the diagnosis challenging and imaging key. In 2018, the British Thoracic Society (BTS) updated the guideline on diagnosis, staging, and follow-up of patients with MPM. These recommendations are discussed in this review of the current literature on imaging of MPM. It is estimated MPM will continue to cause serious morbidity and mortality in the UK late into the 21st century, and internationally, people continue to be exposed to asbestos. We aim to update the reader on current and future imaging strategies, which could aid early diagnosis of pleural malignancy and provide an update on staging and assessment of tumour response.

Guidelines for the cytopathologic diagnosis of epithelioid and mixed-type malignant mesothelioma: Complementary statement from the international mesothelioma interest group, also endorsed by the international academy of cytology and the papanicolaou society of cytopathology. A proposal to be applauded and promoted but which requires updating

The guidelines for the cytopathologic diagnosis of epithelioid and mixed-type malignant mesothelioma produced by the International Mesothelioma Interest Group and which are endorsed by the International Academy of Cytology and the Papanicolaou Society of Cytopathology are reviewed and discussed. This (predominantly) evidence-based document provides a robust and useful framework for diagnosticians and guideline producers to emphasise and promote the value, power and role of cytology in mesothelioma diagnosis and management with comments and suggestions about how the guidelines can be updated and improved in the future.

Thoracic ultrasound competence for ultrasound-guided pleural procedures

Focused thoracic ultrasound has become essential in the guidance and direction of pleural interventions to reduce unwanted complications and as a result now forms a crucial component of physician training. Current training standards along with assessment methods vary widely, and are often not robust enough to ensure adequate competence.This review assesses the current state of training and assessment of thoracic ultrasound competence in various settings, allowing comparison with alternative competency based programmes. Future directions for training and assessment of thoracic ultrasound competence are discussed.

The Immune Microenvironment in Mesothelioma: Mechanisms of Resistance to Immunotherapy

Although mesothelioma is the consequence of a protracted immune response to asbestos fibers and characterized by a clear immune infiltrate, novel immunotherapy approaches show less convincing results as compared to those seen in melanoma and non-small cell lung cancer. The immune suppressive microenvironment in mesothelioma is likely contributing to this therapy resistance. Therefore, it is important to explore the characteristics of the tumor microenvironment for explanations for this recalcitrant behavior. This review describes the stromal, cytokine, metabolic, and cellular milieu of mesothelioma, and attempts to make connection with the outcome of immunotherapy trials.

Short-term integrated rehabilitation for people with newly diagnosed thoracic cancer: a multi-centre randomized controlled feasibility trial

OBJECTIVES

The main objective of this study is to determine the feasibility of recruiting and retaining patients recently diagnosed with thoracic cancer to a trial of short-term integrated rehabilitation; evaluate uptake of theoretically informed components targeting physical function, symptom self-management and participation; estimate sample size requirements for an efficacy trial.

DESIGN

Parallel group randomized controlled feasibility trial.

SETTING

Three U.K. hospitals.

PARTICIPANTS

Patients ⩽eight weeks of thoracic cancer diagnosis, Eastern Cooperative Oncology Group Performance Status 0-3, any cancer stage and treatment plan.

INTERVENTIONS

Participants randomly allocated (1:1) to short-term integrated rehabilitation and standard care or standard care alone over 30 days.

MAIN MEASURES

Primary: participant recruitment and retention, targeting ⩾30% of eligible patients enrolling and ⩾50% of participants reporting outcomes at 30 days. Secondary: intervention fidelity; missing data and performance of outcome measures for self-efficacy, symptoms, physical activity and health-related quality of life.

RESULTS

Of 159 eligible patients approached, 54 (34%) were recruited. A total of 44 (82%) and 39 (72%) participants reported outcomes at 30 and 60 days, respectively. Intervention fidelity was high. Rehabilitation was delivered across 3 (1-3) sessions over 32 (22-45) days (median (range)). Changes in clinical outcomes were modest but most apparent at 60 days for health-related quality of life: Functional Assessment of Cancer Therapy Lung Cancer score median (interquartile range) change 9.7 (-12.0 to 16.0) rehabilitation versus 2.3 (-15.0 to 14.5) standard care.

CONCLUSION

A trial to examine efficacy of short-term integrated rehabilitation for people newly diagnosed with thoracic cancer is feasible. A sample of 336 participants could detect a meaningful effect on health-related quality of life as the primary outcome.

Advances in pleural effusion diagnostics

Introduction: Pleural effusion is a common clinical problem. Yet, in a significant proportion of patients (~20%), the cause of pleural effusion remains unknown. Understanding the diagnostic value of pleural fluid tests is crucial for the development of accurate diagnostic models.Areas covered: This paper provides an overview of latest advances in the diagnosis of pleural effusion based on the best evidence available.Expert opinion: For pleural fluid tests to have a good diagnostic value, it is necessary that data obtained from clinical history, physical examination, and radiological studies are correctly interpreted. Thoracentesis and pleural biopsy should always be performed under image guidance to improve its diagnostic sensitivity and prevent complications. Nucleic acid amplification tests, pleural tissue cultures, and collection of pleural fluid in blood culture bottles improve the diagnostic yield of pleural fluid cultures. Although undiagnosed pleural effusions generally have a favorable prognosis, follow-up is recommended to prevent the development of a malignant pleural effusion.