Accuracy of pleural biopsy using thoracoscopy for the diagnosis of histologic subtype in patients with malignant pleural mesothelioma

Efficacy of cryobiopsy during medical thoracoscopy for diagnosing malignant pleural mesothelioma

OBJECTIVES

Malignant pleural mesothelioma (MPM) is difficult to differentiate from other pleural diseases, and its diagnosis requires adequate tissue sampling. Although medical thoracoscopy is an established diagnostic procedure for pleural diseases, there is no consensus on whether it guarantees a high diagnostic yield for MPM. Cryobiopsy has been shown to have the potential to improve tissue sampling in other diseases; therefore, we aimed to investigate its efficacy in diagnosing MPM.

MATERIAL AND METHODS

Patients who underwent medical thoracoscopy at our institution between January 2013 and June 2023 and were finally diagnosed with MPM were analyzed. Patients who underwent biopsies with forceps and/or electrocautery devices were defined as the conventional group, whereas those who underwent biopsies with an additional cryoprobe were categorized as the cryo group. Diagnostic performance was compared between the two groups.

RESULTS

Among 347 patients who underwent medical thoracoscopy, 69 patients, 34 in the cryo group and 35 in the conventional group, were diagnosed with MPM. The overall diagnostic yield was 76.8 %, and the cryo group had a significantly higher yield than the conventional group (88.2 % vs. 65.7 %, P = 0.044). Furthermore, the subtype was confirmed in most of the patients in the cryo group but only in approximately two-thirds of those in the conventional group (79.4 % vs. 42.9 %, P = 0.003). Regarding safety, two patients (5.9 %) developed pneumothorax in the cryo group, and two (5.7 %) developed pneumonia in the conventional group.

CONCLUSION

Cryobiopsy is effective in improving the subtype confirmation rate as well as MPM diagnostic yield compared to conventional biopsy.

Emerging Radiopharmaceuticals in Pet Imaging for Mesothelioma: A Review of [18F]FDG Alternatives

Mesothelioma is a malignant tumor associated primarily with asbestos exposure, characterized by an aggressive nature and poor prognosis. Accurate diagnosis, staging, and monitoring of therapeutic response are crucial for effective patient management. Along with a computed tomography (CT) scan, fluorodeoxyglucose labeled with fluorine-18 ([18F]FDG) positron emission tomography (PET) is commonly used in mesothelioma evaluation. However, it has some limitations, including lower sensitivity after pleurodesis and poor accuracy for involved lymph node evaluation. Thus, there is the need to explore other agents. The aim of the present review is to analyze the current literature on the use of alternative radiopharmaceuticals for PET imaging in patients with mesothelioma. A comprehensive search of scientific databases (PubMed, Scopus, and Web of Science) for studies published in the last decade was performed by using the following keywords: "mesothelioma" AND "PET" AND "PET/CT" "radiopharmaceuticals", "[18F]FDG alternatives". Articles focused solely on [18F]FDG, non-English publications or preclinical studies, reviews, meeting abstracts, letters to the editors, and editorials were excluded. A qualitative assessment was made by using the Critical Appraisal Skills Programme (CASP) checklist for diagnostic test studies, when applicable. In total, 14 papers were selected; in seven articles more than five patients were enrolled, while the other seven were only clinical cases (enrolling up to two subjects). [18F]/gallium-68 ([68Ga])-labeled fibroblast activation protein inhibitor (FAPI) compounds, [18F]Fluorothymidine ([18F]FLT), methionine labeled with carbon-11 ([11C]MET), and fluoromisonidazole labeled with fluorine-18 ([18F]FMISO) PET/CT were the alternative agents used most often. In 12 articles, [18F]FDG PET/CT was used as a comparator imaging modality. Detection rate of [18F]FDG was similar to the other radiopharmaceuticals ([68Ga]/[18F]-labeled FAPI compounds, [18F]FLT, [18F]FMISO, [11C]MET, and [68Ga]-Pentaxifor), although radiolabeled FAPI seems to exhibit a higher diagnostic performance. [18F]FDG is still a valuable agent in patients with mesothelioma. However, radiolabeled FAPI appears to be promising and its theranostic properties should therefore be further assessed.

The Role of Surgery in Pleural Mesothelioma

Surgery plays a central role in the diagnosis, staging, and management of pleural mesothelioma. Achieving an accurate diagnosis through surgical intervention and identifying the specific histologic subtype is crucial for determining the appropriate course of treatment. The histologic subtype guides decisions regarding the use of chemotherapy, immunotherapy, or multimodality treatment. The goal of surgery as part of multimodality treatment is to accomplish macroscopic complete resection with the eradication of grossly visible and palpable disease. Over the past two decades, many medical centers worldwide have shifted from performing extra-pleural pneumonectomy (EPP) to pleurectomy decortication (PD). This transition is motivated by the lower rates of short-term mortality and morbidity associated with PD and similar or even better long-term survival outcomes, compared to EPP. This review aims to outline the role of surgery in diagnosing, staging, and treating patients with pleural mesothelioma.

Mesothelioma in the pleura, pericardium and peritoneum: Recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

Mesothelioma is a rare malignancy of the serosal membranes that is commonly related to exposure to asbestos. Despite extensive research and clinical trials, prognosis to date remains poor. Consistent, comprehensive and reproducible pathology reporting form the basis of all future interventions for an individual patient, but also ensures that meaningful data are collected to identify predictive and prognostic markers.

METHODS AND RESULTS

This article details the International Collaboration on Cancer Reporting (ICCR) process and the development of the international consensus mesothelioma reporting data set. It describes the 'core' and 'non-core' elements to be included in pathology reports for mesothelioma of all sites, inclusive of clinical, macroscopic, microscopic and ancillary testing considerations. An international expert panel consisting of pathologists and a medical oncologist produced a set of data items for biopsy and resection specimens based on a critical review and discussion of current evidence, and in light of the changes in the 2021 WHO Classification of Tumours. The commentary focuses particularly upon new entities such as mesothelioma in situ and provides background on relevant and essential ancillary testing as well as implementation of the new requirement for tumour grading.

CONCLUSION

We recommend widespread and consistent implementation of this data set, which will facilitate accurate reporting and enhance the consistency of data collection, improve the comparison of epidemiological data, support retrospective research and ultimately help to improve clinical outcomes. To this end, all data sets are freely available worldwide on the ICCR website (www.iccr-cancer.org/data-sets).

Established and new treatment roadmaps for pleural mesothelioma: opinions of the Turkish Collaborative Group

Pleural mesothelioma (PM) is a cancer of the pleural surface, which is aggressive and may be rapidly fatal. PM is a rare cancer worldwide, but is a relatively common disease in Turkey. Asbestos exposure is the main risk factor and the most common underlying cause of the disease. There have been significant improvements in diagnoses and treatments of many malignancies; however, there are still therapeutic challenges in PM. In this review, we aimed to increase the awareness of health care professionals, oncologists, and pulmonologists by underlining the unmet needs of patients with PM and by emphasizing the need for a multidisciplinary treatment and management of PM. After reviewing the general information about PM, we further discuss the treatment options for patients with PM using immunotherapy and offer evidence for improvements in the clinical outcomes of these patients because of these newer treatment modalities.

Prognosis prediction of patients with malignant pleural mesothelioma using conditional variational autoencoder on 3D PET images and clinical data

BACKGROUND

Deep learning (DL) has been widely used for diagnosis and prognosis prediction of numerous frequently occurring diseases. Generally, DL models require large datasets to perform accurate and reliable prognosis prediction and avoid overlearning. However, prognosis prediction of rare diseases is still limited owing to the small number of cases, resulting in small datasets.

PURPOSE

This paper proposes a multimodal DL method to predict the prognosis of patients with malignant pleural mesothelioma (MPM) with a small number of 3D positron emission tomography-computed tomography (PET/CT) images and clinical data.

METHODS

A 3D convolutional conditional variational autoencoder (3D-CCVAE), which adds a 3D-convolutional layer and conditional VAE to process 3D images, was used for dimensionality reduction of PET images. We developed a two-step model that performs dimensionality reduction using the 3D-CCVAE, which is resistant to overlearning. In the first step, clinical data were input to condition the model and perform dimensionality reduction of PET images, resulting in more efficient dimension reduction. In the second step, a subset of the dimensionally reduced features and clinical data were combined to predict 1-year survival of patients using the random forest classifier. To demonstrate the usefulness of the 3D-CCVAE, we created a model without the conditional mechanism (3D-CVAE), one without the variational mechanism (3D-CCAE), and one without an autoencoder (without AE), and compared their prediction results. We used PET images and clinical data of 520 patients with histologically proven MPM. The data were randomly split in a 2:1 ratio (train : test) and three-fold cross-validation was performed. The models were trained on the training set and evaluated based on the test set results. The area under the receiver operating characteristic curve (AUC) for all models was calculated using their 1-year survival predictions, and the results were compared.

RESULTS

We obtained AUC values of 0.76 (95% confidence interval [CI], 0.72-0.80) for the 3D-CCVAE model, 0.72 (95% CI, 0.68-0.77) for the 3D-CVAE model, 0.70 (95% CI, 0.66-0.75) for the 3D-CCAE model, and 0.69 (95% CI 0.65-0.74) for the without AE model. The 3D-CCVAE model performed better than the other models (3D-CVAE, p = 0.039; 3D-CCAE, p = 0.0032; and without AE, p = 0.0011).

CONCLUSIONS

This study demonstrates the usefulness of the 3D-CCVAE in multimodal DL models learned using a small number of datasets. Additionally, it shows that dimensionality reduction via AE can be used to learn a DL model without increasing the overlearning risk. Moreover, the VAE mechanism can overcome the uncertainty of the model parameters that commonly occurs for small datasets, thereby eliminating the risk of overlearning. Additionally, more efficient dimensionality reduction of PET images can be performed by providing clinical data as conditions and ignoring clinical data-related features.

Perioperative discordance in mesothelioma cell type after pleurectomy/decortication-a possible detrimental effect of neoadjuvant chemotherapy due to epithelial to mesenchymal transition?

OBJECTIVES

The goal was to evaluate the accuracy of preoperative histological assessment and the factors affecting the accuracy and the subsequent effect on postoperative survival after surgical treatment for malignant pleural mesothelioma (MPM).

METHODS

We analysed the perioperative course of patients who underwent surgery for MPM in a single institution over a 5-year period. The primary end point was to evaluate the proportion of histological discordance between preoperative assessment and postoperative histological diagnosis. The secondary end point was to evaluate its prognostic effect on postoperative survival after surgical treatment.

RESULTS

One-hundred and twenty-nine patients were included in this study. Histological discordance between preoperative assessment and postoperative histological diagnosis was found in 27 of 129 patients (20.9%): epithelial to biphasic/sarcomatoid (negative discordance) in 24 and biphasic to epithelial (positive discordance) in 3 (P-value < 0.001). All 24 patients who exhibited epithelial-to-mesenchymal transition (EMT) had received neoadjuvant chemotherapy (P-value: 0.006). In the 34 patients who underwent upfront surgery, only 1 case (2.9%) of EMT was identified (P-value: 0.127). EMT was not associated with a less invasive method of biopsy (P-value: 0.058) or with the volume or maximum diameter of the biopsy (P-value: 0.358 and 0.518, respectively), but it was significantly associated with the receipt of neoadjuvant chemotherapy (P-value: 0.006). At a median follow-up of 17 months (IQR: 11.0-28.0), 50 (39%) patients are still alive. Overall survival was significantly reduced in those patients who received neoadjuvant chemotherapy and who exhibited discordance (EMT) compared to those who did not: 11 (95% CI: 6.2-15.8) months versus 19 (95% CI: 14.2-23.8) months (P-value < 0.001). In addition, there was no difference in overall survival between those who received neoadjuvant chemotherapy and those who had upfront surgery: 16 (95% CI: 2.5-19.5) months versus 30 (95% CI: 11.6-48.4) months (P-value: 0.203).

CONCLUSIONS

The association of neoadjuvant chemotherapy with perioperative histological discordance can be explained by EMT, which leads to worse survival. Therefore, there is an argument for the preferential use of upfront surgery in the treatment of otherwise resectable MPM.

Spatially resolved, high-dimensional transcriptomics sorts out the evolution of biphasic malignant pleural mesothelioma: new paradigms for immunotherapy

BACKGROUND

Malignant Pleural Mesothelioma (MPM) is a dreadful disease escaping the classical genetic model of cancer evolution and characterized by wide heterogeneity and transcriptional plasticity. Clinical evolution of MPM is marked by a progressive transdifferentiation that converts well differentiated epithelioid (E) cells into undifferentiated and pleomorphic sarcomatoid (S) phenotypes. Catching the way this transition takes place is necessary to understand how MPM develops and progresses and it is mandatory to improve patients' management and life expectancy. Bulk transcriptomic approaches, while providing a significant overview, failed to resolve the timing of this evolution and to identify the hierarchy of molecular events through which this transition takes place.

METHODS

We applied a spatially resolved, high-dimensional transcriptomic approach to study MPM morphological evolution. 139 regions across 8 biphasic MPMs (B-MPMs) were profiled using the GeoMx™Digital Spatial Profiler to reconstruct the positional context of transcriptional activities and the spatial topology of MPM cells interactions. Validation was conducted on an independent large cohort of 84 MPMs by targeted digital barcoding analysis.

RESULTS

Our results demonstrated the existence of a complex circular ecosystem in which, within a strong asbestos-driven inflammatory environment, MPM and immune cells affect each other to support S-transdifferentiation. We also showed that TGFB1 polarized M2-Tumor Associated Macrophages foster immune evasion and that TGFB1 expression correlates with reduced survival probability.

CONCLUSIONS

Besides providing crucial insights into the multidimensional interactions governing MPM clinical evolution, these results open new perspectives to improve the use of immunotherapy in this disease.

Cytological Diagnostic Procedures in Malignant Mesothelioma

Malignant mesotheliomas (MM) are rare tumors with high mortality rates, whose incidence varies regionally and nationally, and the diagnosis is difficult. Histology-based diagnosis is considered the gold standard despite its low sensitivity of 57-84%. However, recent advances in cytological analysis offer promise for diagnostic advancements. In this study, we reappraised the current cytological guidelines for the MM diagnosis and concluded on their practicability and reliability. The study included 5731 consecutive specimens of pleural effusions from 4552 patients (3026 males of the average age of 67.5 years and 1526 females of the average age of 65.4 years) between December 2017 and January 2000. Out of these patients, 444 (9.8%) were diagnosed with MM. The effusions were examined by immunocytochemistry using routine Giemsa staining. Additionally, hyaluronic acid (HA) was assessed. Cytological findings confirmed 223 out of the 444 MM. The additional 88 cases with negative cytology were corroborated by supplemental assessments of HA above 30 mg/L. Cytological evaluation accomplished the sensitivity of 0.50, specificity of 0.99, and a positive predictive value (PPV) of 0.97 for MM diagnosis. The use of HA determination raised the sensitivity to 0.70 without affecting the specificity or PPV. We conclude that cytological evaluation of effusions aided by the assessment of HA demonstrates the diagnostic sensitivity and specificity for MM no less than the hitherto standard histological evaluation. The cytology-based MM diagnosis may thus be routinely considered when MM is suspected and may offer confirmatory advantages in difficult or doubtful diagnostic cases.

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.

Advances in pleural infection and malignancy

Pleural infection and malignancy are among the most common causes of pleural disease and form the mainstay of pleural practice. There has been significant research and increase in scientific understanding in these areas in the past decade. With regard to pleural infection, the rising incidence remains worrying. An increased awareness allowing earlier diagnosis, earlier escalation of therapy and the use of validated risk stratification measures may improve outcomes. In pleural malignancy, research has enabled clinicians to streamline patient pathways with focus on reducing time to diagnosis, definitive management of malignant pleural effusion and achieving these with the minimum number of pleural interventions. Trials comparing treatment modalities of malignant pleural effusion continue to highlight the importance of patient choice in clinical decision-making. This article aims to summarise some of the most recent literature informing current practice in these two areas.

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 effusions and pneumothorax: Beyond simple plumbing: Expert opinions on knowledge gaps and essential next steps

Pleural diseases affect millions of people worldwide. Pleural infection, malignant pleural diseases and pneumothorax are common clinical challenges. A large number of recent clinical trials have provided an evidence-based platform to evaluate conventional and novel methods to drain pleural effusions/air which reduce morbidity and unnecessary interventions. These successes have generated significant enthusiasm and raised the profile of pleural medicine as a new subspecialty. The ultimate goal of pleural research is to prevent/stop development of pleural effusions/pneumothorax. Current research studies mainly focus on the technical aspects of pleural drainage. Significant knowledge gaps exist in many aspects such as understanding of the pathobiology of the underlying pleural diseases, pharmacokinetics of pleural drug delivery, etc. Answers to these important questions are needed to move the field forward. This article collates opinions of leading experts in the field in highlighting major knowledge gaps in common pleural diseases to provoke thinking beyond pleural drainage. Recognizing the key barriers will help prioritize future research in the quest to ultimately cure (rather than just drain) these pleural conditions.

The 2019 ERS/ESTS/EACTS/ESTRO Guidelines on the Management of Patients With Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is a rare aggressive cancer, with insidious growth, and is associated with poor outcomes that have not improved over the years. A task force made up of members of 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) societies, who are experts in the field of malignant mesothelioma, reviewed the literature from 2009 to 2018 to update the 2009 guidelines concerning epidemiology, diagnosis, staging, and treatment, including surgical, radiotherapy, and medical management, as well as palliative care to provide the best evidence-based recommendations for this patient population.

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.

Diagnostic value of biopsy sampling in predicting histology in patients with diffuse malignant pleural mesothelioma

BACKGROUND

The classification of diffuse malignant mesothelioma into epithelioid, biphasic, and sarcomatoid types is based on histologic patterns. The diagnosis is made on biopsies, and because of intratumoral heterogeneity, they may not be representative of the entire tumor. The number and volume of biopsies needed to reach diagnostic accuracy in diffuse malignant mesothelioma and their prognostic value remain unclear.

METHODS

This study examined 759 consecutive patients with pleural diffuse malignant mesothelioma treated by pleurectomy/decortication or extrapleural pneumonectomy for the presence of epithelioid and/or sarcomatoid histology and classified both the presurgery biopsies (core-needle or thoracoscopic) and surgical resection specimens. The number and volume of biopsies were correlated with pre- and postsurgery histologies and overall survival.

RESULTS

Diffuse malignant mesothelioma was classified as epithelioid (76%), biphasic (18%), sarcomatoid (5%), or indeterminate (1%) in biopsies and as epithelioid (64%), biphasic (32%), and sarcomatoid (4%) in surgical resection specimens (overall concordance, 80.6%). The positive likelihood ratios were 2.4, 13.6, and 90.1 for biopsies with epithelioid, biphasic, and sarcomatoid histologies, respectively. Concordant histologies between biopsies and resections were associated with a higher number of biopsies (median tissue blocks for concordant histologies vs discordant histologies, 3 vs 2; P < .002) but were less associated with a higher volume (median, 1.2 vs 1.1 cm3 ; P = .06). In a multivariate analysis, overall survival was independently predicted by histology in the resection specimen (P < .0001) but not in the biopsy (P = .09).

CONCLUSIONS

In contrast to epithelioid histology, sarcomatoid histology in biopsies is highly accurate. Despite intratumoral heterogeneity, the accuracy of histologic classification increases with the number of tissue blocks examined, emphasizing the diagnostic value of extensive sampling by presurgery biopsies.

Return to intended oncologic treatment after surgery for malignant pleural mesothelioma

OBJECTIVE

Trimodality therapy may prolong survival for patients with resectable malignant pleural mesothelioma. However, many patients are unable to complete therapy. We sought to identify risk factors for failing to complete adjuvant intensity-modulated radiation therapy after cytoreduction for malignant pleural mesothelioma.

METHODS

We performed a single-institution review of those who received an extrapleural pneumonectomy or pleurectomy/decortication for malignant pleural mesothelioma from 2004 to 2017. Multivariable logistic regression was used to assess preoperative or intraoperative risk factors associated with failing to complete adjuvant intensity-modulated radiation therapy.

RESULTS

A total of 160 patients were identified, among whom 94 (59%) received an extrapleural pneumonectomy and 66 (41%) received a pleurectomy/decortication. Adjuvant intensity-modulated radiation therapy was completed among 105 patients (66%). Reasons for failing to complete adjuvant intensity-modulated radiation therapy included mortality (19), dose constraints (21), postoperative morbidity or delayed recovery (11), and refused or unknown status (4). On multivariable analysis, American Society of Anesthesiologists 3+ classification (P = .002) and smoking history (P = .022) were associated with failure to complete adjuvant intensity-modulated radiation therapy, whereas forced expiratory volume in 1 second 70% or less of predicted and pStage 4 (T4) were significant on univariable analysis only. Other factors, including extrapleural pneumonectomy or pleurectomy/decortication, margin status, age, and histology, were not associated with receiving adjuvant intensity-modulated radiation therapy.

CONCLUSIONS

Many patients are unable to complete adjuvant intensity-modulated radiation therapy after cytoreduction. Failure to complete adjuvant intensity-modulated radiation therapy was associated with worse preoperative comorbidity, but not the type of surgery or margin status.

Malignant pleural mesothelioma: diagnostic value of medical thoracoscopy and long-term prognostic analysis

BACKGROUND

Malignant pleural mesothelioma (MPM) is marked by its difficult diagnosis and poor prognosis. Medical thoracoscopy (MT) is an effective and safe procedure for the diagnosis of exudative pleural effusions and many factors associated with poor prognosis of MPM. We conducted this study to investigate the value of MT for diagnosing of MPM and to identify prognostic factors for MPM patients.

METHODS

From July 2005 through June 2014, a total of 833 patients with undiagnosed pleural effusions underwent MT and pleural biopsies were taken. Clinical data of all patients with MPM were retrospectively analyzed, and those with complete follow-up data were analyzed for prognostic factors.

RESULTS

Eventually, MPM was the final diagnosis in 40 patients. Diagnostic efficiency of MT for MPM was 87.5%, since diagnosis of MPM failed to be established in 5 patients during the initial MT. Median survival was 17.1 mo (95% confidence interval: 13.6-20.7 mo). MT findings of pleural adhesion and plaques were adverse prognostic factors for MPM. In addition, old age, male gender, smoking history, histological type, poor staging, no treatment, low total protein level in pleural fluid, and computed tomographic findings such as pulmonary consolidation or infiltration, mediastinal lymphopathy, pulmonary mass or nodules, and pleural nodularity were also poor prognostic factors for MPM.

CONCLUSIONS

MT is safe with a high positive rate in the diagnosis of MPM, and pleural adhesion and plaques seen under MT may be the adverse prognostic factors for MPM. Multiple clinical characteristics can affect the survival of MPM patients.

Diagnostic Utility of Pleural Fluid Cell Block versus Pleural Biopsy Collected by Flex-Rigid Pleuroscopy for Malignant Pleural Disease: A Single Center Retrospective Analysis

Background

Some trials recently demonstrated the benefit of targeted treatment for malignant disease; therefore, adequate tissues are needed to detect the targeted gene. Pleural biopsy using flex-rigid pleuroscopy and pleural effusion cell block analysis are both useful for diagnosis of malignancy and obtaining adequate samples. The purpose of our study was to compare the diagnostic utility between the two methods among patients with malignant pleural disease with effusion.

Methods

Data from patients who underwent flex-rigid pleuroscopy for diagnosis of pleural effusion suspicious for malignancy at the National Cancer Center Hospital, Japan between April 2011 and June 2014 were retrospectively reviewed. All procedures were performed under local anesthesia. At least 150 mL of pleural fluid was collected by pleuroscopy, followed by pleural biopsies from the abnormal site.

Results

Thirty-five patients who were finally diagnosed as malignant pleural disease were included in this study. Final diagnoses of malignancy were 24 adenocarcinoma, 1 combined adeno-small cell carcinoma, and 7 malignant pleural mesothelioma (MPM), and 3 metastatic breast cancer. The diagnostic yield was significantly higher by pleural biopsy than by cell block [94.2% (33/35) vs. 71.4% (25/35); p = 0.008]. All patients with positive results on cell block also had positive results on pleural biopsy. Eight patients with negative results on cell block had positive results on pleural biopsy (lung adenocarcinoma in 4, sarcomatoid MPM in 3, and metastatic breast cancer in 1). Two patients with negative results on both cell block and pleural biopsy were diagnosed was sarcomatoid MPM by computed tomography-guided needle biopsy and epithelioid MPM by autopsy.

Conclusion

Pleural biopsy using flex-rigid pleuroscopy was efficient in the diagnosis of malignant pleural diseases. Flex-rigid pleuroscopy with pleural biopsy and pleural effusion cell block analysis should be considered as the initial diagnostic approach for malignant pleural diseases presenting with effusion.

[Surgical therapy of malignant pleural mesothelioma]

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor disease, which rapidly leads to death if untreated. In Germany the incidence of newly occurring disease is expected to reach a peak in the coming 5 years. An R0 resection for MPM is technically impossible; therefore, the aim of surgical procedures is to achieve the maximum amount of cytoreduction. There are two established surgical techniques for treatment of MPM, extrapleural pneumonectomy and tumor pleurectomy with decortication. The type and extent of surgery are currently controversially discussed. Within multimodal therapy concepts including cytoreductive surgery, long-term remission is possible in selected patients. When choosing the appropriate surgical therapy the high incidence of recurrence has to be borne in mind.

The Third Italian Consensus Conference for Malignant Pleural Mesothelioma: State of the art and recommendations

Malignant Pleural Mesothelioma (MPM) remains a relevant public health issue, and asbestos exposure is the most relevant risk factor. The incidence has considerably and constantly increased over the past two decades in the industrialized countries and is expected to peak in 2020-2025. In Italy, a standardized-rate incidence in 2011 among men was 3.5 and 1.25 per 100,000 in men and women, respectively, and wide differences are noted among different geographic areas. The disease remains challenging in terms of diagnosis, staging and treatment and an optimal strategy has not yet been clearly defined. The Third Italian Multidisciplinary Consensus Conference on Malignant Pleural Mesothelioma was held in Bari (Italy) in January 30-31, 2015. This Consensus has provided updated recommendations on the MPM management for health institutions, clinicians and patients.

The role of thoracic surgery in the management of mesothelioma: an expert opinion on the limited evidence

Surgery has a key role at different points in the management of Malignant Pleural Mesothelioma. Diagnosis with video assisted thoracoscopy offers excellent sensitivity and specificity and a direct view of the pleural cavity to verify the extent of the tumor. Nodal involvement can be assessed by mediastinoscopy and either talc pleurodesis or partial pleurectomy can be used for symptom control in advanced stage disease. Extra Pleural Pneumonectomy (EPP) and Extended Pleurectomy Decortication (EPD) are used to prolong survival although the benefit of radical surgery has not has been fully clarified; EPP failed to show its benefit in the MARS trial and EPD is currently under investigation in the MARS2 trial. More randomized prospective trial data are needed to fully understand the role of radical surgery in the treatment of pleural mesothelioma.

Dataset for Reporting of Malignant Mesothelioma of the Pleura or Peritoneum: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

CONTEXT

-The International Collaboration on Cancer Reporting is a not-for-profit organization formed by the Royal Colleges of Pathologists of Australasia and the United Kingdom; the College of American Pathologists; the Canadian Association of Pathologists-Association Canadienne des Pathologists, in association with the Canadian Partnership Against Cancer; and the European Society of Pathology. Its goal is to produce common, internationally agreed upon, evidence-based datasets for use throughout the world.

OBJECTIVE

-To describe a dataset developed by the Expert Panel of the International Collaboration on Cancer Reporting for reporting malignant mesothelioma of both the pleura and peritoneum. The dataset is composed of "required" (mandatory) and "recommended" (nonmandatory) elements.

DESIGN

-Based on a review of the most recent evidence and supported by explanatory commentary.

RESULTS

-Eight required elements and 7 recommended elements were agreed upon by the Expert Panel to represent the essential information for reporting malignant mesothelioma of the pleura and peritoneum.

CONCLUSIONS

-In time, the widespread use of an internationally agreed upon, structured, pathology dataset for mesothelioma will lead not only to improved patient management but also provide valuable data for research and international benchmarks.

Malignant Mesothelioma Diagnosed by Bronchoscopic Biopsy

Malignant mesothelioma is a rare malignant neoplasm that arises from mesothelial surfaces of the pleural cavity, peritoneal cavity, tunica vaginalis, or pericardium. Typically, pleural fluid cytology or closed pleural biopsy, surgical intervention (video thoracoscopic biopsy or open thoracotomy) is conducted to obtain pleural tissue specimens. However, endobronchial lesions are rarely seen and cases diagnosed from bronchoscopic biopsy are also rarely reported. We reported the case of a 77-year-old male who was diagnosed as malignant mesothelioma on bronchoscopic biopsy from obstructing masses of the endobronchial lesion.

Reproducibility of histological subtyping of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) has a very poor prognosis. Although clinical stage is currently the only reliable prognostic factor, histologic subtyping reportedly also affects prognosis. Some studies propose reclassification of pleomorphic epithelioid as biphasic or sarcomatoid MPM. This study assessed prognostic significance and interobserver agreement in MPM subtyping of small biopsy specimens. We analyzed biopsy specimens, and clinical and survival data from records of 108 patients who were diagnosed between 2000 and 2010 at the Institute of Pathology University of Zagreb School of Medicine, of whom 98 had epithelioid MPM, six biphasic MPM, and four sarcomatoid MPM. Among epithelioid subtypes, 44 (44.9 %) were solid, 19 (19.4 %) tubulopapillary, 18 (18.4 %) acinar, six (6.1 %) adenomatoid, five (5.1 %) pleomorphic, four (4.1 %) trabecular, and two (2.0 %) micropapillary subtype. Interobserver reliability for histological diagnosis was found to be κ = 0.72 (P < 0.001). Median overall survival for epithelioid MPM was 10.5 months with an interquartile range (IQR) of 5.8-28.0 months but significantly shorter for the pleomorphic subtype (3 [IQR 3.0-8.0] months; P = 0.034), but not significantly different from biphasic (6.5 [IQR 3.5-15.3] months) and sarcomatoid mesothelioma (4.0 [IQR 1.3-6.8] months; P = 0.270). We found strong reproducibility of MPM subtyping with good interobserver agreement. Furthermore, our results indicate that pleomorphic subtype to be a predictor of poor prognosis and support classifying it with sarcomatoid or biphasic MPM, as patients with the pleomorphic, biphasic, or sarcomatoid subtype show similarly poor overall survival.

Diagnosis and treatment of malignant pleural mesothelioma

There are three major challenges in the diagnosis of malignant pleural mesothelioma: mesothelioma must be distinguished from benign mesothelial hyperplasia; malignant mesothelioma (and its subtypes) must be distinguished from metastatic carcinoma; and invasion of structures adjacent to the pleura must be demonstrated. The basis for clarifying the first two aspects is determination of a panel of monoclonal antibodies with appropriate immunohistochemical evaluation performed by highly qualified experts. Clarification of the third aspect requires sufficiently abundant, deep biopsy material, for which thoracoscopy is the technique of choice. Video-assisted needle biopsy with real-time imaging can be of great assistance when there is diffuse nodal thickening and scant or absent effusion. Given the difficulties of reaching an early diagnosis, cure is not generally achieved with radical surgery (pleuropneumonectomy), so liberation of the tumor mass with pleurectomy/decortication combined with chemo- or radiation therapy (multimodal treatment) has been gaining followers in recent years. In cases in which surgery is not feasible, chemotherapy (a combination of pemetrexed and platinum-derived compounds, in most cases) with pleurodesis or a tunneled pleural drainage catheter, if control of pleural effusion is required, can be considered. Radiation therapy is reserved for treatment of pain associated with infiltration of the chest wall or any other neighboring structure. In any case, comprehensive support treatment for pain control in specialist units is essential: this acquires particular significance in this type of malignancy.

Is There a Role for a Needle Thoracoscopic Pleural Biopsy under Local Anesthesia for Pleural Effusions?

Background

A closed pleural biopsy is commonly performed for diagnosing patients exhibiting pleural effusion if prior thoracentesis is not diagnostic. However, the diagnostic yield of such biopsies is unsatisfactory. Instead, a thoracoscopic pleural biopsy is more useful and less painful.

Methods

We compared the diagnostic yield of needle thoracoscopic pleural biopsy performed under local anesthesia with that of closed pleural biopsy. Sixty-seven patients with pleural effusion were randomized into groups A and B. Group A patients were subjected to closed pleural biopsies, and group B patients were subjected to pleural biopsies performed using needle thoracoscopy under local anesthesia.

Results

The diagnostic yields and complication rates of the two groups were compared. The diagnostic yield was 55.6% in group A and 93.5% in group B (p<0.05). Procedure-related complications developed in seven group A patients but not in any group B patients. Of the seven complications, five were pneumothorax and two were vasovagal syncope.

Conclusion

Needle thoracoscopic pleural biopsy under local anesthesia is a simple and safe procedure that has a high diagnostic yield. This procedure is recommended as a useful diagnostic modality if prior thoracentesis is non-diagnostic.

Semirigid thoracoscopy: an effective method for diagnosing pleural malignancies

Background

Thoracoscopy with a semirigid instrument is a recent technique for diagnosing pleural diseases. The purpose of this study was to report diagnostic yield and complications of the method.

Patients and methods.

Patients with pleural effusion of unknown origin and/or pleural irregularities suspicious for pleural malignancy were included after less invasive means of diagnosis had failed. All procedures were performed under local anaesthesia with intravenous sedation/analgesia with a single point of entry with a semirigid thoracoscope (Olympus LTF-160). Data were collected prospectively between 2008 and 2012.

Results

One hundred fifteen thoracoscopies were performed on 111 patients. The median age was 65 years (range 28–86 years), 14.4% were female and 85.6% male. Seventy-three (65.8%) patients had malignant pleural disease (malignant mesothelioma, metastatic cancer) and 38 (34.2%) had benign disease. The sensitivity, negative predictive value, and accuracy of the procedure for malignancy were 96.0%, 93.0%, and 97.4% respectively. Pleurodesis was carried out in 34 patients; in 32 (94.1%) it was assessed as successful after 1 month. There were 24 adverse events: three empyemas/pleural infections, three bronchopleural fistulae after chest tube placement and lung re-expansion, five patients had excessive pain after pleurodesis, six patients had sedation-associated hypotension, and seven patients had self-limited fever after plerodesis. One patient died 11 days after a procedure for advanced carcinoma.

Conclusions

Semirigid thoracoscopy is an accurate and safe method for evaluation of pleural diseases and useful for therapeutic talc pleurodesis.

Accuracy of diagnostic biopsy for the histological subtype of malignant pleural mesothelioma

INTRODUCTION

Histological subtype is an established prognostic factor in malignant pleural mesothelioma (MPM). We retrospectively investigated the accuracy of classifying histological subtype on diagnostic biopsies and examined the impact of different diagnostic procedures on the outcome.

METHODS

Consecutive patients with histologically confirmed MPM who underwent extrapleural pneumonectomy (EPP) from 1994 to 2009 were included. Patient records were reviewed, and the initial diagnoses of histological subtype were obtained. The archival EPP specimens were reviewed by a panel of pathologists. The histological subtype obtained at review was compared with the initial diagnosis.

RESULTS

Eighty-five patients underwent EPP. Two patients achieved a pathological complete response after neoadjuvant chemotherapy, leaving 83 patients to be included in this review. Different diagnostic methods were used before EPP: 81% thoracoscopy; 7% thoracotomy; 11% computed tomography-guided procedure; and 1% other. Patients determined to have an epithelial subtype (n = 64) at EPP were diagnosed correctly at initial diagnostic biopsy in 84% of cases, whereas patients considered to have a biphasic subtype (n = 19) at EPP were diagnosed correctly at diagnostic biopsy in 26% of cases. The sensitivity and specificity of diagnostic biopsy for epithelial MPM was 93% and 31%, respectively. The overall subtype misclassification rate was 20%. Biopsy by thoracotomy was most accurate in subtype classification (83%) compared with thoracoscopy (74%) and computed tomography-guided procedure (44%).

CONCLUSIONS

The determination of histological subtype from a diagnostic biopsy is difficult due to sampling error, but an adequate specimen obtained from surgical biopsy increases the accuracy of subtype classification compared with radiological-guided biopsies.

Medical thoracoscopy

PURPOSE OF REVIEW

The technique and clinical applications of medical thoracoscopy have substantially evolved in the last few decades. The recent development of a semirigid thoracoscope, which is handled similarly to a bronchoscope, has made this procedure more attractive to pulmonologists. We will review the latest data on clinical applications, recently developed techniques, and safety of medical thoracoscopy, focusing mainly on its role in thoracic malignancies.

RECENT FINDINGS

Recent data confirm the high diagnostic yield of medical thoracoscopy - both with rigid and semirigid instruments - in detecting pleural metastases and determining the origin of pleural effusions. The degree of pleural adhesions found during thoracoscopy has been proposed by some authors as a prognostic factor for survival in patients with malignant pleural effusion. A large prospective multicenter study has established the safety of talc poudrage with large-particle talc, showing no cases of acute respiratory distress syndrome.

SUMMARY

Medical thoracoscopy is an excellent tool to establish diagnosis in patients with exudative pleural effusion of unclear origin. It is highly valuable in clarifying the origin of pleural effusions in patients with lung cancer, as the presence of a malignant pleural effusion is associated with poor survival and precludes the possibility of treatment with curative intention. Pleurodesis with talc poudrage is efficacious and well tolerated, especially with the use of large-particle talc.

Accuracy of pathological diagnosis of mesothelioma cases in Japan: clinicopathological analysis of 382 cases

Incidences of mesothelioma are on the rise in Japan. However, the accurate frequency of mesothelioma occurrence is still unknown. The aim of this study is to clarify the accuracy of pathological diagnosis of mesothelioma. Among the 2742 mesothelioma death cases extracted from the document "Vital Statistics of Japan" for 2003-2005, pathological materials were obtained for 382 cases. After these materials were reviewed and immunohistochemical analyses were conducted, mesothelioma was diagnosed by discussions based on clinical and radiological information. Sixty-five cases (17.0%) were categorized as "definitely not/unlikely" mesotheliomas, and 273 cases (71.5%) were categorized as "probable/definite" mesotheliomas. The percentage of "probable/definite" pleural and peritoneal mesothelioma cases in males was 74.3% and 87.5%, respectively, and that of pleural cases in females was 59.2%; however, the percentage of "probable/definite" peritoneal cases in females was only 22.2%. These results suggest that the diagnostic accuracy of mesothelioma is relatively low in females and in cases of peritoneal and sarcomatoid subtype mesotheliomas; furthermore, approximately 15% of cases of deaths due to mesothelioma in Japan are diagnostically suspicious.

Kinetics of soluble mesothelin in patients with malignant pleural mesothelioma during treatment

RATIONALE

Previous data suggested that serum levels of soluble mesothelin (SM) are related to tumor size and may have prognostic significance in malignant pleural mesothelioma (MPM).

OBJECTIVES

We tested the hypothesis that this marker could also be useful for monitoring response to treatment.

METHODS

Serial measurements of SM were determined in 40 patients diagnosed with MPM and subjected to gene-transfer therapy using intrapleural infusion of an adenoviral vector expressing human IFN-beta or conventional treatment (mainly chemotherapy).

MEASUREMENTS AND MAIN RESULTS

In patients with baseline SM levels greater than 1 nM/L and disease progression after therapy, SM levels increased by 2.1 nM/L at two, 5.2 nM/L at four and 1.3 nM/L at 6 months. Patients with initial SM below 1 nM/L had a similar but more moderate increase of SM over time. Patients who responded to treatment or were considered stable had an initial small decrease of SM followed by a return to baseline values after 6 months of follow-up. In patients with baseline SM levels greater than 1 nM/L, increasing levels were associated with a significantly shorter median survival than in patients with stable or decreasing SM levels (4.4 vs. 27.7 months; P = 0.012).

CONCLUSIONS

Increasing serum levels of SM were associated with disease progression and worse outcome, whereas stable or decreasing values suggested response to treatment. If confirmed in larger series, SM could be used to monitor patients with malignant pleural mesothelioma under treatment.

Malignant mesothelioma 2008

PURPOSE OF REVIEW

Mesothelioma is an aggressive malignancy of the pleura with poor survival. There will be approximately 3000 cases of mesothelioma in the United States annually. Multimodality treatment including neoadjuvant chemotherapy in selected individuals followed by extrapleural pneumonectomy and radiation has been studied in recent trials for its effects on disease free and overall survival This review provides a general overview of malignant mesothelioma with a summary of the most significant articles from within the past year as well as from the past.

RECENT FINDINGS

Areas of recent interest include the evaluation of osteopontin and mesothelin as new tumor markers for mesothelioma. New phase III trials have been performed to evaluate the use of combined chemotherapy regimens.

SUMMARY

Malignant mesothelioma is a very difficult malignancy to treat. Patients with the disease usually have an occupational asbestos exposure, and in some, viral exposure with SV40. There have been many historical treatments including combinations of local control with surgery and radiation as well as attempts to prevent systemic failure with chemotherapy. Novel therapies including intrapleural chemotherapy, photodynamic therapy and hyperthermic perfusion have also been used with some success. Finally there are several attempts at immunomodulating and targeted treatments, which are in phase I/II trials.