A phase II trial of surgical resection and adjuvant high-dose hemithoracic radiation for malignant pleural mesothelioma

Chinese expert consensus on the diagnosis and treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a malignant tumor originating from the pleura, and its incidence has been increasing in recent years. Due to the insidious onset and strong local invasiveness of MPM, most patients are diagnosed in the late stage and early screening and treatment for high-risk populations are crucial. The treatment of MPM mainly includes surgery, chemotherapy, and radiotherapy. Immunotherapy and electric field therapy have also been applied, leading to further improvements in patient survival. The Mesothelioma Group of the Yangtze River Delta Lung Cancer Cooperation Group (East China LUng caNcer Group, ECLUNG; Youth Committee) developed a national consensus on the clinical diagnosis and treatment of MPM based on existing clinical research evidence and the opinions of national experts. This consensus aims to promote the homogenization and standardization of MPM diagnosis and treatment in China, covering epidemiology, diagnosis, treatment, and follow-up.

The Impact of Adjuvant Hemithoracic Radiation on Outcomes in Patients With Stage I-III Malignant Pleural Mesothelioma: A Dual Registry Analysis

BACKGROUND

The outcomes associated with receipt of adjuvant radiation in patients after surgery for MPM are poorly understood.

OBJECTIVE

The objective of this study was to use 2 registries to compare the outcomes of patients receiving adjuvant radiation or no radiation after definitive surgery for pathologic stage I-III MPM.

METHODS

Patients with resected pathologic stage I-III MPM were identified from the Duke University registry (1996-2016) and National Cancer Database (NCDB) (2004-2015). The primary outcome was overall survival. Propensity score-matched and landmark subgroup analyses were performed.

RESULTS

A total of 212 institutional and 1615 NCDB patients met criteria. In both cohorts, patients who underwent radiation were more likely to have margin-negative resection and more advanced pathologic stage. At a landmark time of 4.4 and 4.7 months from surgery, Duke [hazard ratio (HR) 1.14; 95% confidence interval (CI) 0.62-2.11] and NCDB patients (HR 0.97; 95% CI 0.81-1.17) who received adjuvant radiation did not experience improved survival compared to those who did not receive radiation in multivariable analysis. Duke patients who received radiation had similar incidence of recurrence and time to both overall recurrence and ipsilateral recurrence (HR 0.87; 95% CI 0.43-1.77) compared to those who did not. Duke patients experienced 100 grade 1/2, 21 grade 3/4, and one grade 5 toxicity events during radiation.

CONCLUSIONS

In this dual registry analysis of patients with resected stage I-III MPM, the receipt of adjuvant hemithoracic radiation was not associated with improved survival compared to no radiation.

A Phase II Window of Opportunity Study of Neoadjuvant PD-L1 versus PD-L1 plus CTLA-4 Blockade for Patients with Malignant Pleural Mesothelioma

PURPOSE

We report the results of a phase II, randomized, window-of-opportunity trial of neoadjuvant durvalumab versus durvalumab plus tremelimumab followed by surgery in patients with resectable malignant pleural mesothelioma (MPM; NCT02592551).

PATIENTS AND METHODS

The primary objective was alteration of the intratumoral CD8/regulatory T cell (Treg) ratio after combination immune checkpoint blockade (ICB) therapy. Secondary and exploratory objectives included other changes in the tumor microenvironment, survival, safety, tumor pathologic response (PR), and systemic immune responses.

RESULTS

Nine patients received monotherapy and 11 received combination therapy. Seventeen of the 20 patients (85%) receiving ICB underwent planned thoracotomy. Both ICB regimens induced CD8 T-cell infiltration into MPM tumors but did not alter CD8/Treg ratios. At 34.1 months follow-up, patients receiving combination ICB had longer median overall survival (not reached) compared with those receiving monotherapy (14.0 months). Grade ≥3 immunotoxicity occurred in 8% of patients in the monotherapy group and 27% of patients in the combination group. Tumor PR occurred in 6 of 17 patients receiving ICB and thoracotomy (35.3%), among which major PR (>90% tumor regression) occurred in 2 (11.8%). Single-cell profiling of tumor, blood, and bone marrow revealed that combination ICB remodeled the immune contexture of MPM tumors; mobilized CD57+ effector memory T cells from the bone marrow to the circulation; and increased the formation of tertiary lymphoid structures in MPM tumors that were rich in CD57+ T cells.

CONCLUSIONS

These data indicate that neoadjuvant durvalumab plus tremelimumab orchestrates de novo systemic immune responses that extend to the tumor microenvironment and correlate with favorable clinical outcomes.

Activation of Adaptive and Innate Immune Cells via Localized IL2 Cytokine Factories Eradicates Mesothelioma Tumors

PURPOSE

IL2 immunotherapy has the potential to elicit immune-mediated tumor lysis via activation of effector immune cells, but clinical utility is limited due to pharmacokinetic challenges as well as vascular leak syndrome and other life-threatening toxicities experienced by patients. We developed a safe and clinically translatable localized IL2 delivery system to boost the potency of therapy while minimizing systemic cytokine exposure.

EXPERIMENTAL DESIGN

We evaluated the therapeutic efficacy of IL2 cytokine factories in a mouse model of malignant mesothelioma. Changes in immune populations were analyzed using time-of-flight mass cytometry (CyTOF), and the safety and translatability of the platform were evaluated using complete blood counts and serum chemistry analysis.

RESULTS

IL2 cytokine factories enabled 150× higher IL2 concentrations in the local compartment with limited leakage into the systemic circulation. AB1 tumor burden was reduced by 80% after 1 week of monotherapy treatment, and 7 of 7 of animals exhibited tumor eradication without recurrence when IL2 cytokine factories were combined with anti-programmed cell death protein 1 (aPD1). Furthermore, CyTOF analysis showed an increase in CD69+CD44+ and CD69-CD44+CD62L- T cells, reduction of CD86-PD-L1- M2-like macrophages, and a corresponding increase in CD86+PD-L1+ M1-like macrophages and MHC-II+ dendritic cells after treatment. Finally, blood chemistry ranges in rodents demonstrated the safety of cytokine factory treatment and reinforced its potential for clinical use.

CONCLUSIONS

IL2 cytokine factories led to the eradication of aggressive mouse malignant mesothelioma tumors and protection from tumor recurrence, and increased the therapeutic efficacy of aPD1 checkpoint therapy. This study provides support for the clinical evaluation of this IL2-based delivery system. See related commentary by Palanki et al., p. 5010.

Repurposing clofazimine for malignant pleural mesothelioma treatment - In-vitro assessment of efficacy and mechanism of action

AIMS

Malignant pleural mesothelioma (MPM) is a rare cancer of lungs' pleural cavity, with minimally effective therapies available. Thus, there exists a necessity for drug repurposing which is an attractive strategy for drug development in MPM. Repurposing of an old FDA-approved anti-leprotic drug, Clofazimine (CFZ), presents an outstanding opportunity to explore its efficacy in treating MPM.

MAIN METHODS

Cytotoxicity, scratch assay, and clonogenic assays were employed to determine CFZ's ability to inhibit cell viability, cell migration, and colony growth. 3D Spheroid cell culture studies were performed to identify tumor growth inhibition potential of CFZ in MSTO-211H cell line. Gene expression analysis was performed using RT-qPCR assays to determine the CFZ's effect of key genes. Western blot studies were performed to determine CFZ's ability to induce apoptosis its effect to induce autophagy marker.

KEY FINDINGS

CFZ showed significant cytotoxicity against both immortalized and primary patient-derived cell lines with IC₅₀ values ranging from 3.4 μM (MSTO-211H) to 7.1 μM (HAY). CFZ significantly impaired MPM cell cloning efficiency, migration, and tumor spheroid formation. 3D Spheroid model showed that CFZ resulted in reduction in spheroid volume. RT-qPCR data showed downregulation of genes β-catenin, BCL-9, and PRDX1; and upregulation of apoptosis markers such as PARP, Cleaved caspase 3, and AXIN2. Additionally, immunoblot analysis showed that CFZ down-regulates the expression of β-catenin (apoptosis induction) and up-regulates p62, LC3B protein II (autophagy inhibition).

SIGNIFICANCE

It can be concluded that CFZ could be a promising molecule to repurpose for MPM treatment which needs numerous efforts from further studies.

Multimodal Treatment of Malignant Pleural Mesothelioma: Real-World Experience with 112 Patients

Malignant pleural mesothelioma (MPM) is a rare pleural cancer associated with asbestos exposure. According to current evidence, the combination of chemotherapy, surgery and radiotherapy improves patients’ survival. However, the optimal sequence and weighting of the respective treatment modalities is unclear. In anticipation of the upcoming results of the MARS-2 trial, we sought to determine the relative impact of the respective treatment modalities on complications and overall survival in our own consecutive institutional series of 112 patients. Fifty-seven patients (51%) underwent multimodality therapy with curative intent, while 55 patients (49%) were treated with palliative intent. The median overall survival (OS) of the entire cohort was 16.9 months (95% CI: 13.4−20.4) after diagnosis; 5-year survival was 29% for patients who underwent lung-preserving surgery. In univariate analysis, surgical treatment (p < 0.001), multimodality therapy (p < 0.001), epithelioid subtype (p < 0.001), early tumor stage (p = 0.02) and the absence of arterial hypertension (p = 0.034) were found to be prognostic factors for OS. In multivariate analysis, epithelioid subtype was associated with a survival benefit, whereas the occurrence of complications was associated with worse OS. Multimodality therapy including surgery significantly prolonged the OS of MPM patients compared with multimodal therapy without surgery.

New Era for Malignant Pleural Mesothelioma: Updates on Therapeutic Options

Malignant pleural mesothelioma (MPM) is a rare malignancy with few treatment options. Recent advances have led to US Food and Drug Administration approvals and changes in the standard of care with a novel biomedical device approved for use with platinum-pemetrexed, and also for immunotherapy agents to be included as a frontline treatment option in unresectable disease. Although predictive biomarkers for systemic therapy are not currently in use in clinical practice, it is essential to correctly identify the MPM histology to determine an optimal treatment plan. Patients with nonepithelioid MPM may have a greater magnitude of benefit to dual immunotherapy checkpoint inhibitors and this regimen should be preferred in the frontline setting for these patients. However, all patients with MPM can derive benefit from immunotherapy treatments, and these agents should ultimately be used at some point during their treatment journey. There are ongoing studies in the frontline unresectable setting that may further define the frontline therapy space, but a critical area of research will need to focus on the immunotherapy refractory population. This review article will describe the new developments in the areas of biology with genomics and chromothripsis, and also focus on updates in treatment strategies in radiology, surgery, radiation, and medical oncology with cellular therapies. These recent innovations are generating momentum to find better therapies for this disease.

IRF3 Knockout Results in Partial or Complete Rejection of Murine Mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MESO) has a poor prognosis despite aggressive treatment with surgery, radiation and chemotherapy, and novel therapeutic approaches are needed. IRF3 is a downstream molecule of the cGAS/STING signaling pathway, but its roles have not been investigated in MESO.

METHODS

Various murine mesothelioma cell lines were inoculated into wild type (WT) and IRF3 knockout (IRF3KO) mice to compare tumor growth. AE17-bearing mice were treated with local radiotherapy (LRT) to evaluate the effect on tumor growth, and immune cell infiltration was analyzed by flow cytometry 20 days after tumor inoculation. TCGA data were used to examine the relationship between mRNA expression of IRF3 and genes of the cGAS/STING signaling cascade on prognosis in MESO. Correlations between gene expression of IRF3, cGAS/STING signaling pathway, and immune checkpoints were analyzed in TCGA MESO and our scRNA-Seq data from MESO patients.

RESULTS

In mouse mesothelioma models, AK7, RN5 and ZiP3 were completely rejected in IRF3KO mice 20 days after the tumor challenge. AE17tumor volume was slightly larger than WT mice around day 10 before shrinking and becoming significantly smaller than WT mice on day 20. LRT accelerated tumor shrinkage of AE17 tumors in IRF3KO mice. Compared with WT mice, the number of macrophages infiltrating the tumor of IRF3KO mice was significantly reduced, and CD4⁺ T cells and CD8⁺IFNγ⁺ T cells were significantly increased. TCGA data showed that IRF3 expression was an unfavorable prognostic factor in MESO patients. IRF3 expression, the cGAS/STING signaling pathway, and immune checkpoints were positively correlated.

CONCLUSION

IRF3 could play a critical role in the tumor immune microenvironment of MESO.

Staged removal of artificial patches for thoracic empyema after extrapleural pneumonectomy for diffuse malignant pleural mesothelioma

A 69-year-old man with occupational exposure to asbestos was referred to our hospital with right diffuse malignant pleural mesothelioma. He underwent extrapleural pneumonectomy with reconstruction of the pericardium and diaphragm using elongated polytetrafluoroethylene patches, followed by postoperative chemotherapy and chest wall irradiation. One year later, he was hospitalized because of a right empyema caused by Escherichia coli infection. As chest drainage and systemic antibiotics did not eliminate the abscess around the artificial patches, a Clagett window was created. To avoid mediastinal and liver overshift into the right thoracic cavity, we only performed partial resection of the diaphragm patch and incision of the artificial pericardium. After 19 days of irrigation and dressing change, the artificial patches were completely removed. Two months later, the patient provided a culture-negative sample and had an improved nutritional status; we therefore performed closure of the Clagett window with thoracoplasty. He did not experience recurrence of empyema.

[The Current Therapy of Asbestos-Associated Malignant Pleural Mesothelioma - An Expert Consensus Paper]

Asbestos-related mesotheliomas belong to the group of the most frequent occupational diseases in Germany, reaching about 1,000 new cases per year. The disease has a dismal prognosis because most tumors remain asymptomatic for a long time and therefore are diagnosed as incidental findings at later stages.During the last decade the German Social Accident Insurance (DGUV) has made considerable efforts to prepone the diagnosis in order to detect the disease at earliest possible stages. These efforts resulted in new findings showing that, in a high-risk group, a combination of the biomarkers calretinin and mesothelin was able to advance the diagnosis up to 12 months.Ideally, the diagnosis of a mesothelioma at an early stage has to be accompanied by the best possible individualized therapy. Standard therapeutic strategies are surgery and chemotherapy, added by radiotherapy and psycho-oncology. In recent years, several new therapeutic avenues are being explored. This review comprehensively presents both old and new therapeutic options in mesothelioma, based on international Leitlinien and new studies.

Use of Continuous Positive Airway Pressure (CPAP) to Limit Diaphragm Motion-A Novel Approach for Definitive Radiation Therapy for Inoperable Pleural Mesothelioma: A Pilot Study

Simple Summary

Radiotherapy is an important part of the multimodality approach to treating malignant pleural mesothelioma. In recent studies there is a new trend to treat patients with intact lungs instead of following surgery. This treatment creates significant concerns regarding lung toxicity. We describe two methods to reduce that toxicity. One is the use of constant pulmonary airway pressure (CPAP) to inflate the lungs during treatment. The second is utilizing a novel method of planning and delivering radiotherapy called volumetric modulated arc therapy (VMAT).

Abstract

Malignant pleural mesothelioma (MPM) is a deadly disease and radiotherapy (RT) plays an important role in its management. Recent developments in technique have made it is possible to deliver RT to MPM in the intact lung. However, it is imperative to reduce normal lung doses. We present a pilot study examining the use of CPAP and VMAT radiotherapy to reduce toxicity when treating MPM, involving three consecutive patients with MPM, not amenable to surgery, who were treated according to Helsinki committee approval. Patients were simulated using four-dimentional CT simulation with the assistance of CPAP lung inflation, then were treated using both IMRT and VMAT techniques. Radiation lung dose was optimized based on accepted lung dose constraints. Patients were followed for toxicity as well as local control and survival. Results: Three patients were treated with CPAP-based IMRT treatment. These patients tolerated the treatment and DVH constraints were able to be met. The comparison plans among the four VMAT arcs and the IMRT static field treatment were able to accomplish the treatment planning objectives without significant advantages with either technique. The treatment combined with CPAP reduced the normal lung dose in MPM patients with intact lungs. This technique is worthy of further investigation.

Neoadjuvant pemetrexed plus cisplatin followed by pleurectomy for malignant pleural mesothelioma

PURPOSE

Despite becoming the preferred surgical technique for malignant pleural mesothelioma, pleurectomy/decortication has received few prospective clinical trials. Therefore, the Japan Mesothelioma Interest Group conducted a prospective multi-institutional study to evaluate the feasibility of neoadjuvant chemotherapy followed by pleurectomy/decortication.

METHODS

Patients with histologically confirmed, resectable malignant pleural mesothelioma underwent neoadjuvant chemotherapy comprising pemetrexed 500 mg/m² plus cisplatin 75 mg/m² for 3 cycles, followed by pleurectomy/decortication. The primary end point was macroscopic complete resection rate regardless of the surgical technique used.

RESULTS

Among the 24 patients enrolled, 20 received neoadjuvant chemotherapy and 18 proceeded to surgery, all of whom achieved macroscopic complete resection. Pleurectomy/decortication was performed in 15 patients. The trial satisfied the primary end point, with a macroscopic complete resection rate of 90% (18/20, 95% confidence interval, 68.3-98.8). No treatment-related 30- and 90-day mortality occurred. The overall survival after 1 and 2 years and median overall survival after registration were 95.0% (95% confidence interval, 69.5-99.3), 70.0% (95% confidence interval, 45.1-85.3), and 3.45 years (95% confidence interval, 1.64 to not available), respectively. The cumulative incidence of progression after 1 and 2 years and median time to progression were 33.3% (95% confidence interval, 17.3-64.1), 61.1% (95% confidence interval, 42.3-88.3), and 1.71 years (95% confidence interval, 1.00-2.99), respectively. The best postoperative value for forced expiratory volume was 78.0% of preoperative values.

CONCLUSIONS

Neoadjuvant chemotherapy followed by pleurectomy/decortication was feasible with acceptable survival and mortality/morbidity. Postoperative pulmonary function was approximately 80% of the preoperative pulmonary function.

Extrapleural Pneumonectomy versus Pleurectomy/Decortication for Malignant Pleural Mesothelioma

BACKGROUND

Whether extrapleural pneumonectomy (EPP) or extended pleurectomy/decortication (P/D) is the optimal resection for malignant pleural mesothelioma (MPM) remains controversial. We therefore compared perioperative outcomes and long-term survival of patients who underwent EPP vs P/D.

METHODS

Patients with the diagnosis of MPM who underwent either EPP or P/D from 2000 to 2019 were identified from our departmental database. Propensity score matching was performed to minimize potential confounders for EPP or P/D. Survival analysis was performed by the Kaplan-Meier method and Cox multivariable analysis.

RESULTS

Of 282 patients, 187 (66%) underwent EPP and 95 (34%) P/D. Even with propensity score matching, perioperative mortality was significantly higher for EPP than for P/D (11% vs. 0%; P=0.031), when adjusted for perioperative mortality, median overall survival between EPP and P/D was 15 vs. 22 months, respectively (P=0.276). Cox multivariable analysis for the matched cohort identified epithelioid histology (hazard ratio [HR], 0.56; P=0.029), macroscopic complete resection (HR, 0.41; P=0.004), adjuvant radiation therapy (HR, 0.57; P=0.019), and more recent operative years (HR, 0.93; P=0.011)-but not P/D-to be associated with better survival. Asbestos exposure (HR, 2.35; P=0.003) and pathological nodal disease (HR, 1.61; P=0.048) were associated with worse survival.

CONCLUSIONS

In a multimodality treatment setting, P/D and EPP had comparable long-term oncological outcomes, although P/D had much lower perioperative mortality. The goal of surgical cytoreduction should be macroscopic complete resection achieved by the safest operation a patient can tolerate.

Epidemiology, diagnosis and treatment of the malignant pleural mesothelioma, a narrative review of literature

The malignant pleural mesothelioma is a very aggressive tumor which is arising from mesothelial cells and is associated with asbestos exposure. It is a heterogeneous cancer that shows a complex pattern of molecular changes, including genetic, chromosomic, and epigenetic abnormalities. The malignant pleural mesothelioma is characterized by a silent and slow clinical progression with an average period of 20–40 years from the asbestos exposure phase to the start of the symptoms. Unfortunately, to date, the therapeutic options are very limited, especially if the tumor is detected late. This narrative review provides an extended overview of the present evidence in the literature regarding the epidemiology, diagnostic pathways and treatment approaches of the malignant pleural mesothelioma. The treatment of mesothelioma has evolved slowly over the last 20 years not only from a surgical point of view but also radiotherapy, chemotherapy and immunotherapy play nowadays a key role. Several surgical strategies are available ranging from extrapleural pneumonectomy to cytoreductive surgery but a multidisciplinary approach seems to be mandatory because a single approach has not proved to date to be resolutive. New non-surgical treatment options appear to be promising but the results have to be taken in account with caution because clear evidence with high-quality studies is still lacking

Landmark Trials in the Surgical Management of Mesothelioma

The treatment of mesothelioma has evolved slowly over the last 20 years. While surgery as a standalone treatment has fallen out of favor, the importance of multimodality treatment consisting of combinations of chemotherapy, radiotherapy, and surgery have become more common in operable, fit patients. In this review, we discuss trials in surgery, chemotherapy, and radiation that have shaped contemporary multimodality treatment of this difficult malignancy, and we touch on the new and emerging immunotherapeutic and targeted agents that may change the future treatment of this disease. We also review the multimodality treatment regimens, with particular attention to trimodality therapy and neoadjuvant hemithoracic radiation strategies.

Surgery for malignant pleural mesothelioma after radiotherapy (SMART): final results from a single-centre, phase 2 trial

BACKGROUND

A novel approach for managing malignant pleural mesothelioma, surgery for mesothelioma after radiotherapy (SMART), consisting of a short accelerated course of high-dose, hemithoracic, intensity modulated radiotherapy (IMRT) followed by extrapleural pneumonectomy was developed. The aim of this study was to evaluate the clinical feasibility of the SMART protocol.

METHODS

In this single-centre, phase 2 trial, patients aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-2, with histologically proven, resectable, cT1-3N0M0 disease who had previously untreated malignant pleural mesothelioma were eligible for inclusion. Patients received 25 Gy in five daily fractions over 1 week to the entire ipsilateral hemithorax with a concomitant 5 Gy boost to high risk areas followed by extrapleural pneumonectomy within 1 week. Adjuvant chemotherapy was offered to patients with ypN+ disease on final pathology. The primary endpoint was feasibility, which was defined as the number of patients with 30-day perioperative treatment-related death (grade 5 events) or morbidity (grade 3 or 4 events). A key secondary endpoint was cumulative incidence of distant recurrence. The final analysis was done on an intention-to-treat basis (including all eligible patients). This trial is registered with ClinicalTrials.gov, NCT00797719.

FINDINGS

Between Nov 1, 2008, and Oct 31, 2019, 102 patients were enrolled onto the trial and 96 eligible patients were treated with SMART on protocol and included in the analysis. Extrapleural pneumonectomy was done at a median of 5 days (range 2-12) after completing IMRT. 47 (49%) patients had 30-day perioperative grade 3-4 events and one (1%) patient died within 30 days perioperatively (grade 5 event; pneumonia). After a median follow-up of 46·8 months (IQR 13·4-61·2), the 5-year cumulative incidence of distant recurrence was 62 (63·3% [95% CI 52·3-74·4]). The most common first sites of recurrence were the contralateral chest (33 [46%] of 72 patients) and the peritoneal cavity (32 [44%]).

INTERPRETATION

Results from this study suggest that extrapleural pneumonectomy after radiotherapy can be done with good early and long-term results. However, minimising grade 4 events on the protocol is technically demanding and might affect survival beyond the post-operative period.

FUNDING

Princess Margaret Hospital Foundation Mesothelioma Research Fund.

Proton therapy for thoracic malignancies: a review of oncologic outcomes

Introduction: Radiotherapy is an integral component in the treatment of the majority of thoracic malignancies. By taking advantage of the steep dose fall-off characteristic of protons combined with modern optimization and delivery techniques, proton beam therapy (PBT) has emerged as a potential tool to improve oncologic outcomes while reducing toxicities from treatment.Areas covered: We review the physical properties and treatment techniques that form the basis of PBT as applicable for thoracic malignancies, including a brief discussion on the recent advances that show promise to enhance treatment planning and delivery. The dosimetric advantages and clinical outcomes of PBT are critically reviewed for each of the major thoracic malignancies, including lung cancer, esophageal cancer, mesothelioma, thymic cancer, and primary mediastinal lymphoma.Expert opinion: Despite clear dosimetric benefits with PBT in thoracic radiotherapy, the improvement in clinical outcomes remains to be seen. Nevertheless, with the incorporation of newer techniques, PBT remains a promising modality and ongoing randomized studies will clarify its role to determine which patients with thoracic malignancies receive the most benefit. Re-irradiation, advanced disease requiring high cardio-pulmonary irradiation volume and younger patients will likely derive maximum benefit with modern PBT.

Radiation Therapy for Malignant Pleural Mesothelioma

The treatment of malignant pleural mesothelioma with radiation therapy has always been a technical challenge. For many years, radiation therapy was delivered after extrapleural pneumonectomy with acceptable results. As the utilization of pleurectomy/decortication increased, techniques, such as pleural intensity-modulated radiation therapy (IMRT) have been introduced. The experience with these techniques have grown and multiple trials using IMRT, both in the setting of extrapleural pneumonectomy or pleurectomy, are being conducted to assess its effectiveness.

Addition of radiotherapy to surgery and chemotherapy improves survival in localized malignant pleural mesothelioma: A Surveillance, Epidemiology, and End Results (SEER) study

INTRODUCTION

Malignant pleural mesothelioma (MPM) is a devastating disease with poor survival outcomes for most patients. Optimizing therapeutic approaches is thus vital, but has been hampered by a dearth of randomized trials to guide decision making. We used a population-level database to evaluate the impact of radiotherapy as a component of trimodality therapy on overall survival (OS) in MPM.

METHODS

We retrospectively reviewed the SEER Radiation/Chemotherapy database for patients with MPM who received surgery and chemotherapy, with or without radiotherapy. A propensity score-matched analysis with inverse probability of treatment weighting (IPTW) was performed. Weight-adjusted univariate KM analysis was performed and doubly robust, IPTW-adjusted multivariable cox proportional hazards regression modeling was also performed to quantify the effect of radiotherapy on OS in trimodality therapy for MPM.

RESULTS

1015 patients were identified. 678 patients received surgery and chemotherapy, and 337 patients received trimodality therapy. For patients with localized disease, OS was significantly improved with trimodality therapy (HR 0.56, CI 0.4 - 0.8, p = 0.001), which persisted with IPTW adjustment (HR 0.65, CI 0.49 - 0.95, p = 0.0248). No significant benefit was seen for patients with regional or distant disease. On multivariate analysis, positive predictors of survival after IPTW adjustment were female sex, diagnosis after 2005, and left-sided disease.

CONCLUSIONS

These findings support a significant benefit to OS by incorporating radiotherapy as a component of trimodality therapy for patients with localized MPM compared to only surgery and chemotherapy. It does not provide a significant overall survival benefit for patients with regional or metastatic disease.

Surgery for Mesothelioma After Radiation Therapy (SMART); A Single Institution Experience

Background: The optimal treatment sequence for localized malignant pleural mesothelioma (MPM) is controversial. We aimed to assess outcomes and toxicities of treating localized MPM with neoadjuvant radiation therapy (RT) followed by extrapleural pneumonectomy (EPP). Methods: Patients were enrolled on an institutional protocol of surgery for mesothelioma after radiation therapy (SMART) between June 2016 and May 2017. Eligible patients were adults with MPM localized to the ipsilateral pleura. Patients underwent staging with PET/CT, pleuroscopy, bronchoscopy/EBUS, mediastinoscopy, and laparoscopy. Five fractions of RT were delivered using intensity modulated radiation therapy (IMRT), with 30 Gy delivered to gross disease and 25 Gy to the entire pleura. EPP was performed 4-10 days following completion of RT. Results: Five patients were treated on protocol. Median age was 62 years (range 36-66). Histology was epithelioid on initial biopsy in all patients, but one was found to have biphasic histology after surgery. Three patients had surgeon-assessed gross total resection, and two had gross residual disease. While all patients were clinically node negative by pretreatment staging, three had positive nodal disease at surgery. Patients were hospitalized for a median 24 days (range 5-69) following surgery. Two patients developed empyema, one of whom developed respiratory failure and subsequently renal failure requiring dialysis, while the other required multiple surgical debridements. Two patients developed atrial fibrillation with rapid ventricular response after surgery, one of whom developed acute respiratory distress requiring intubation and tracheostomy. At last follow-up, one patient died at 1.4 years after local and distant progression, two were alive with local and distant progression, and the remaining two were alive without evidence of disease at 0.1 and 2.7 years. Median time to progression was 9 months. Three patients received salvage chemotherapy. Conclusions: SMART provided promising oncologic outcomes at the cost of significant treatment related morbidity. Due to the significant treatment associated morbidity and favorable treatment alternatives, we have not broadly adopted SMART at our institution.

Hemizygous loss of NF2 detected by fluorescence in situ hybridization is useful for the diagnosis of malignant pleural mesothelioma

Neurofibromatosis type 2 (NF2) gene, a tumor suppressor gene located on chromosome 22q12.2, is frequently abnormal in mesothelioma. Recent studies have revealed the effectiveness of diagnostic assays for differentiating malignant pleural mesothelioma from reactive mesothelial hyperplasia. These include detection of homozygous deletion of the 9p21 locus by fluorescence in situ hybridization (FISH) (9p21 FISH), loss of expression of BAP1 as detected by immunohistochemistry, and loss of expression of methylthioadenosine phosphorylase (MTAP) as detected by immunohistochemistry. However, the application of FISH detection of NF2 gene deletion (NF2 FISH) in differentiation of malignant pleural mesothelioma from reactive mesothelial hyperplasia has not been fully evaluated. In this study, we investigated whether NF2 FISH, either alone or in a combination with other diagnostic assays (9p21 FISH, MTAP immunohistochemistry, and BAP1 immunohistochemistry), is effective for distinguishing malignant pleural mesothelioma from reactive mesothelial hyperplasia. This study cohort included malignant pleural mesothelioma (n = 47) and reactive mesothelial hyperplasia cases (n = 27) from a period between 2001 and 2017. We used FISH to examine deletion status of NF2 and 9p21 and immunohistochemistry to examine expression of MTAP and BAP1 in malignant pleural mesothelioma and in reactive mesothelial hyperplasia. Hemizygous NF2 loss (chromosome 22 monosomy or hemizygous deletion) was detected in 25 of 47 (53.2%) mesothelioma cases. None of the mesothelioma cases showed homozygous NF2 deletion. Hemizygous NF2 loss showed 53.2% sensitivity and 100% specificity in differentiating malignant pleural mesothelioma from reactive mesothelial hyperplasia. A combination of NF2 FISH, 9p21 FISH, and BAP1 immunohistochemistry yielded greater sensitivity (100%) than that detected for either diagnostic assay alone (53.2% for NF2 FISH, 78.7% for 9p21 FISH, 70.2% for MTAP immunohistochemistry, or 57.4% for BAP1 immunohistochemistry). Thus, NF2 FISH in combination with other diagnostic assays is effective for distinguishing malignant pleural mesothelioma from reactive mesothelial hyperplasia.

Malignant Pleural Mesothelioma: State-of-the-Art on Current Therapies and Promises for the Future

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the pleural surface associated with asbestos exposure. The median survival of MPM patients is a mere 8-14 months, and there are few biomarkers and no cure available. It is hoped that, eventually, the incidence of MPM will drop and remain low and constant, given that most nations have banned the use of asbestos, but in the meantime, the incidence in Europe is still growing. The exact molecular mechanisms that explain the carcinogenicity of asbestos are not known. Standard therapeutic strategies for MPM include surgery, often coupled with chemotherapy and/or radiotherapy, in a small percentage of eligible patients and chemotherapy in tumors considered unresectable with or without adjuvant radiotherapy. In recent years, several new therapeutic avenues are being explored. These include angiogenesis inhibitors, synthetic lethal treatment, miRNA replacement, oncoviral therapies, and the fast-growing field of immunotherapy alone or in combination with chemotherapy. Of particular promise are the multiple options offered by immunotherapy: immune checkpoint inhibitors, tumor vaccines, and therapies taking advantage of tumor-specific antigens, such as specific therapeutic antibodies or advanced cell-based therapies exemplified by the CAR-T cells. This review comprehensively presents both old and new therapeutic options in MPM, focusing on the results of the numerous recent and on-going clinical trials in the field, including the latest data presented at international meetings (AACR, ASCO, and ESMO) this year, and concludes that more work has to be done in the framework of tailored therapies to identify reliable targets and novel biomarkers to impact MPM management.

Extrapleural pneumonectomies for pleural mesothelioma

Introduction: Malignant pleural mesothelioma (MPM) is a fatal malignancy for which there is no definitive cure. The most effective multimodality treatment in prolonging survival is still matter of debate. Surgery remains one of the cornerstones in the multimodality therapy for MPM. Extra-pleural pneumonectomy and pleurectomy/decortication are the two main curative-intent procedures; however, the superiority of one technique over the other is still debated. This review aims to assess short- and long-term results of extrapleural pneumonectomy for MPM.Areas covered: This article focuses on the role of extrapleural pneumonectomy in MPM. A systematic review was performed by using electronic databases to identify studies that included patients treated by this procedure for MPM. Endpoints included overall survival, disease-free survival, recurrence rate, perioperative mortality, and morbidity.Expert commentary: This paper offers an overview of the results that are currently obtained in patients undergoing extrapleural pneumonectomy for MPM. The benefit of surgical treatments in MPM is still debated and its primary goal should be the achievement of a macroscopic complete resection. Several alternative multimodality protocols exist, with specific advantages and drawbacks; therefore, individualization of care for each patient is fundamental. The complexity of the surgical treatment mandates that patients be referred to specialized centers.

Emerging therapies in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare cancer of the pleural surfaces frequently related to asbestos exposure. It is characterized by a poor prognosis even for patients treated with trimodality therapy, including surgery, chemotherapy and radiotherapy. Moreover, the majority of patients are not candidates for surgery due to disease advanced stage or medical comorbidities. For these patients, the survival rate is even lower and few therapeutic options are currently available. Nevertheless, many interesting novel approaches are under investigation, among which immunotherapy represents one of the most promising emerging strategies. In this review, we will discuss the role of new therapeutic options, particularly immunotherapy, and present the results of the most important and promising clinical trials.

Scientific Advances and New Frontiers in Mesothelioma Therapeutics

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer that arises from the mesothelial surface of the pleural and peritoneal cavities, the pericardium, and rarely, the tunica vaginalis. The incidence of MPM is expected to increase worldwide in the next two decades. However, even with the use of multimodality treatment, MPM remains challenging to treat, with a 5-year survival rate of less than 5%. The International Association for the Study of Lung Cancer has gathered experts in different areas of mesothelioma research and management to summarize the most significant scientific advances and new frontiers related to mesothelioma therapeutics.

Preliminary results of entire pleural intensity-modulated radiotherapy in a neoadjuvant setting for resectable malignant mesothelioma

Purpose

The purpose of this study is to evaluate the safety and efficacy of the multimodality treatment with neoadjuvant intensity-modulated radiotherapy (IMRT) for resectable clinical T1-3N0-1M0 malignant pleural mesothelioma (MPM).

Materials and Methods

A total of eleven patients who received neoadjuvant chemotherapy and radiotherapy between March 2016 and June 2018 were reviewed. Patients received 25 Gy in 5 fractions to entire ipsilateral hemithorax with helical tomotherapy.

Results

All of patients were men with a median age of 56 years. Epithelioid subtype was found in 10 patients. All patients received neoadjuvant chemotherapy with pemetrexed-cisplatin regimen. Ten patients (90.9%) completed 25 Gy/5 fractions and one (9.0%) completed 20 Gy/4 fractions of radiotherapy. IMRT was well tolerated with only one acute grade 3 radiation pneumonitis. Surgery was performed 1 week (median, 8 days; range, 1 to 15 days) after completing IMRT. Extrapleural pneumonectomy was performed in 4 patients (36.3%), extended pleurectomy/decortication in 2 (18.2%) and pleurectomy/decortications in 5 (63.6%). There was no grade 3+ surgical complication except two deaths after EPP in 1 month. Based on operative findings and pathologic staging, adjuvant chemotherapy was delivered in 7 patients (63.6%), and 2 (18.2%) were decided to add adjuvant radiotherapy. After a median follow-up of 14.6 months (range, 2.8 to 30 months), there were 3 local recurrence (33.3%) and 1 distant metastasis (11.1%).

Conclusion

Neoadjuvant entire pleural IMRT can be delivered with a favorable radiation complication. An optimal strategy has to be made in resectable MPM patients who would benefit from neoadjuvant radiation and surgery. Further studies are needed to look at long-term outcomes.

Pattern of failure after adjuvant radiotherapy following extrapleural pneumonectomy of pleural mesothelioma in the SAKK 17/04 trial

Postoperative radiotherapy after extrapleural pneumonectomy of malignant pleural mesothelioma was investigated in the randomized phase II trial SAKK17/04. The relapse rate within the high and/or low-dose PTV without previous distant failure was 24%, the isolated in-field-relapse rate within the PTVs was 5% and the distant relapse rate outside of the PTVs was 81%. Clinical outcome was mainly determined by distant disease progression outside of the radiation field.

Updates in the diagnosis and treatment of malignant pleural mesothelioma

PURPOSE OF REVIEW

This review article describes current diagnostic and treatment modalities for malignant pleural mesothelioma (MPM).

RECENT FINDINGS

Few randomized trials in MPM have demonstrated improved survival with current therapies. A randomized trial of first-line chemotherapy with and without bevacizumab in unresectable MPM is the only randomized trial of a new treatment regimen to demonstrate a survival benefit since cisplatin with pemetrexed became the standard of care for unresectable MPM in 2003. Unfortunately, in unresectable MPM, first-line chemotherapy alone or in combination with bevacizumab has demonstrated only limited improvements in overall survival. Recently, in nonrandomized observational studies, multimodality treatments with chemotherapy, surgery, radiation, and novel therapies have been associated with prolonged survival in select patients. Currently, there are no FDA approved second-line therapies, and clinical trial enrollment is recommended for second-line treatment.

SUMMARY

MPM remains difficult to treat and has an overall poor prognosis despite current multimodality treatment. Thoracoscopy with multiple pleural biopsies can provide adequate tissue specimens for diagnostic testing to distinguish histologic MPM subtypes and perform molecular profiling, which influence prognosis and treatment options. In early clinical trials, immunotherapies and therapies directed against cancer-associated antigens and oncogenic alterations are emerging as promising future treatments.

Defining the role of adjuvant radiotherapy for malignant pleural mesothelioma: a propensity-matched landmark analysis of the National Cancer Database

Background

Multimodality therapy may prolong survival among resectable malignant pleural mesothelioma (MPM). However, the role of adjuvant radiation remains controversial. We explored a large nationwide database to determine whether adjuvant radiation is associated with improved survival.

Methods

The National Cancer Database (NCDB) was queried to identify patients with MPM who received cancer-directed surgery between 2004-2013. Adjuvant radiation included intensity modulated radiation therapy or conformal 3D radiation. Propensity matching was performed with a 150-day landmark to address survivorship bias. Cox regression was used with an interaction term between pathologic stage and radiation.

Results

A total of 2,846 patients were identified as having undergone cancer-directed surgery for MPM; among whom 213 (7%) received adjuvant radiation. Adjuvant radiation was associated with improved survival among those who were stage I-II (P=0.024), but not stage III or IV (P=0.890 and P=0.183, respectively). After propensity matching, adjuvant radiation was associated with improved survival for those who were stage I-II [hazard ratio (HR) 0.52, P=0.035], whereas no similar effect was observed for those who were stage III or IV (P=0.190 and P=0.562, respectively). Multivariable regression revealed that sarcomatoid histology (HR 1.80, P=0.018) and stage IV disease (HR 1.65, P=0.033) were also associated with worse survival.

Conclusions

Adjuvant radiation was associated with improved survival among those with pathologic stage I-II MPM. No survival advantage was observed for those with pathologic stage III or stage IV MPM, however. Our results justify the need for further prospective trials to investigate the utility of adjuvant radiotherapy among those with MPM.

Extra-pleural pneumonectomy

The extra-pleural pneumonectomy (EPP) is a standardised surgical procedure born for pleural tuberculosis and later used in pleural cancer treatment, especially in malignant pleural mesothelioma (MPM). This systematic review aimed to focus on the actual overall EPP role in surgical oncology. The literature search was performed from January 1985 to January 2018 In PubMed, Embase, and Cochrane according to PRISMA protocol. The search was restricted to publications in English with the research words "extrapleural pneumonectomy", "malignant pleural mesothelioma", "pleural malignancies". The results were then filtered focusing only on papers with series of patients treated with EPP, for mesothelioma and non-mesothelioma malignancies. The search was restricted to publications in English. We found a 5-year overall survival (OS) ranging from 0 to 78%. The peri-operative mortality and morbidity ranged from 0 to 11.8% and 0 to 82.6%, respectively. The most represented and described post-operative complications reported were ARDS, pericardial tamponade, cardiac herniation, pulmonary embolism, respiratory infections, respiratory failure, atrial arrhythmia, myocardial infarction. In referral centres and selected patients, EPP is a cytoreductive or radical surgical treatment in extended pleural malignancies. Prospective studies are needed to standardise the timing of the procedure in a multimodality treatment program, according to the oncological and functional indications, to keep an acceptable complications rate and post-operative quality of life status.

The Role of Adjuvant Radiotherapy in the Treatment of Pleural Mesothelioma

BACKGROUND

Pleural mesothelioma is a rare but aggressive form of cancer. Local recurrence represents the majority of treatment failures and overall survival (OS) outcomes remain dismal. Adding locoregional treatment with radiotherapy after surgical resection has been considered but its role remains uncertain.

OBJECTIVE

The purpose of this study was to evaluate the outcomes of adjuvant radiation therapy (RT) for patients with malignant pleural mesothelioma.

METHODS

The National Cancer Data Base (NCDB) was queried (2004-2013) for patients with malignant mesothelioma. Patients were divided into three groups: observation, surgery alone, and surgery followed by adjuvant RT. Statistics included Fisher's exact or Chi square tests to analyze categorical proportions between groups, Kaplan-Meier analysis to evaluate OS, and Cox proportional hazards modeling to determine variables associated with OS. Propensity matching was performed to make comparisons between homogenous groups.

RESULTS

Overall, the surgery plus radiotherapy group had a higher median survival (21.4 months) compared with surgery alone (16.59 months) [p < 0.001]. RT was more likely to be delivered after extrapleural pneumonectomy than with lung-sparing surgical approaches. On multivariable analysis, receipt of surgery plus radiotherapy, chemotherapy administration, and higher socioeconomic status were associated with improved OS (p < 0.0001). After propensity matching, receipt of surgery plus radiotherapy and chemotherapy administration were still associated with improved OS (p < 0.05).

CONCLUSIONS

In the treatment of malignant pleural mesothelioma, adjuvant radiotherapy after surgical intervention was associated with improved OS. This study is the largest study of adjuvant radiotherapy to date, and our findings highlight the need for additional prospective data.

Computed tomography features of local pleural recurrence in patients with malignant pleural mesothelioma treated with intensity-modulated pleural radiation therapy

OBJECTIVE

This study was conducted in order to describe the computed tomography (CT) features of local pleural recurrence in patients with malignant pleural mesothelioma undergoing intensity-modulated pleural radiation therapy (IMPRINT) as part of multimodality treatment.

METHODS

In this observational study, 58 patients treated with IMPRINT between September 21, 2004, and December 1, 2014 were included. Baseline and follow-up CT scans were qualitatively assessed. On follow-up scans, pleural thickening was categorized as unchanged, decreased, or new/increased. New/increased pleural abnormality was subcategorized as diffuse smooth pleural thickening, diffuse nodular pleural thickening, focal pleural nodule, or multiple pleural nodules. To identify features more frequently present at the time of local recurrence, follow-up scans with local recurrence were matched to four control scans; exact conditional logistic regression was performed.

RESULTS

Twenty-one (36%) patients had local pleural recurrence and 20 (34%) patients had nonpleural recurrence; 3 patients had both types of recurrence. The 1-year cumulative incidence rate of local recurrence was 27% (95% confidence interval 15, 39). On follow-up scans, three patterns of pleural abnormality were significantly associated with local recurrence: new/increased multiple pleural nodules (10 (48%) positive scans vs 0 control scans), new/increased diffuse nodular pleural thickening (7 (33%) positive scans vs 1 (1%) control scans), and new/increased focal pleural nodule (3 (14%) positive scans vs 1 (1%) control scan) (p < 0.001 for all).

CONCLUSIONS

Multiple new/increased pleural nodules are the feature most commonly present at local recurrence following IMPRINT; however, any pattern of increased nodular pleural thickening is suspicious.

KEY POINTS

• In patients with mesothelioma receiving intensity-modulated pleural radiation as part of multimodality therapy, increasing multiple pleural nodules is the computed tomography feature most commonly present at local recurrence. • In these patients, any CT pattern of increased nodular pleural thickening should be considered suspicious for local recurrence. • The most common sites of nonpleural recurrence were lung parenchyma, thoracic lymph nodes, and peritoneum.

Making cold malignant pleural effusions hot: driving novel immunotherapies

Malignant pleural effusions, arising from either primary mesotheliomas or secondary malignancies, heralds advanced disease and poor prognosis. Current treatments, including therapeutic thoracentesis and tube thoracostomy, are largely palliative. The immunosuppressive environment within the pleural cavity includes myeloid derived suppressor cells, T-regulatory cells, and dysfunctional T cells. The advent of effective immunotherapy with checkpoint inhibitors and adoptive cell therapies for lung cancer and other malignancies suggests a renewed examination of local and systemic therapies for this malady. Prior strategies reporting remarkable success, including instillation of the cytokine interleukin-2, perhaps coupled with checkpoint inhibitors, should be further evaluated in the modern era.

A Novel Prospective Study Assessing the Combination of Photodynamic Therapy and Proton Radiation Therapy: Safety and Outcomes When Treating Malignant Pleural Mesothelioma

Malignant pleural mesothelioma remains difficult to treat, with high failure rates despite optimal therapy. We present a novel prospective trial combining proton therapy (PT) and photodynamic therapy (PDT) and the largest-ever mesothelioma PT experience (n = 10). PDT photosensitizers included porfimer sodium (2 mg·kg-1 ; 24 h drug-light interval) or 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) (4 mg·m-2 ;48 h) with wavelengths of 630 nm to 60J·cm-2 and 665 nm to 15-45J·cm-2 , respectively. With a median age of 69 years, patients were predominantly male (90%) with epithelioid histology (100%) and stage III-IV disease (100%). PT was delivered to a median of 55.0 CGE/1.8-2.0 CGE (range 50-75 CGE) adjuvantly (n = 8) or as salvage therapy (n = 2) following extended pleurectomy/decortication (ePD)/PDT. Two-year local control was 90%, with distant and regional failure rates of 50% and 30%, respectively. All patients received chemotherapy, and four received immunotherapy. Surgical complications included atrial fibrillation (n = 3), pneumonia (n = 2), and deep vein thrombosis (n = 2). Median survival from PT completion was 19.5 months (30.3 months from diagnosis), and 1- and 2-year survival rates were 58% and 29%. No patient experienced CTCAEv4 grade ≥2 acute or late toxicity. Our prolonged survival in very advanced-stage patients compares favorably to survival for PT without PDT and photon therapy with PDT, suggesting possible spatial or systemic cooperativity and immune effect.

Early-stage Clinical Characterization of Malignant Pleural Mesothelioma

BACKGROUND/AIM

A strategy for improving survival of malignant pleural mesothelioma (MPM) patients is earlier diagnosis paired with earlier stage implementation of therapeutic interventions. This study aimed to determine the clinical signs of early-stage MPM to aid an earlier diagnosis and earlier-stage intervention.

MATERIALS AND METHODS

Out of the 72 cases in our institution, 40 cases with ¹⁸F-FDG-PET/CT-negative MPM were retrospectively identified between 2007 and 2015. Overall survival rates were determined and compared with pathological features, histology, and treatment.

RESULTS

The biphasic histological type of early-stage MPM was characterized by poor prognosis (p=0.0006). Additionally, the cytology-negative group (Class III and below) showed significantly shorter survival times (p=0.0290). There was no significant difference in survival between patients who received pleurectomy and those who received chemotherapy only (p=0.6991). Bimodal therapy resulted in a longer survival rate than trimodal therapy.

CONCLUSION

In early-stage PET-negative MPM cases, biphasic histology and pleural effusion of Class III and below correlated with a poor prognosis. Surgical treatment using pleurectomy/decortication resulted in higher patient survival outcomes than therapy with extrapleural pneumonectomy.

Current and Future Management of Malignant Mesothelioma: A Consensus Report from the National Cancer Institute Thoracic Malignancy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation

On March 28- 29, 2017, the National Cancer Institute (NCI) Thoracic Malignacy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation convened the NCI-International Association for the Study of Lung Cancer- Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting in Bethesda, Maryland. The goal of the meeting was to bring together lead academicians, clinicians, scientists, and the U.S. Food and Drug Administration to focus on the development of clinical trials for patients in whom malignant pleural mesothelioma has been diagnosed. In light of the discovery of new cancer targets affecting the clinical development of novel agents and immunotherapies in malignant mesothelioma, the objective of this meeting was to assemble a consensus on at least two or three practice-changing multimodality clinical trials to be conducted through NCI's National Clinical Trials Network.

Moderately Hypofractionated Helical IMRT, FDG-PET/CT-guided, for Progressive Malignant Pleural Mesothelioma in Patients With Intact Lungs

INTRODUCTION

The objective of this study was to present the outcomes of moderately hypofractionated helical intensity-modulated radiation therapy (HT) with/without simultaneous integrated boost (SIB) on fluorodeoxyglucose-positron emission tomography (FDG-PET) positive areas (gross tumor volume [GTV]-PET) for patients with progressive malignant pleural mesothelioma (MPM) after previous treatments.

METHODS AND MATERIALS

From May 2006 to April 2014, 51 patients with a median age of 68.8 years (range, 38.6-82 years) were treated. There were 41 men and 10 women; 43 epithelioid MPM and 8 sarcomatoid, involving the left pleura in 25 patients and the right pleura in 26 patients. The initial stage was: I, 11 patients; II, 14 patients; III, 17 patients; and IV, 9 patients. Chemotherapy was prescribed for 46 patients, for 6 cycles (range, 0-18 cycles). Eighteen patients had pleurectomy/decortication, and 33 had talc pleurodesis. FDG-PET was used for target identification. A median dose of 56 Gy/25 fractions was prescribed to the involved pleura, and SIB to 62.5 Gy to GTV-PET was added in 38 patients.

RESULTS

The median survival from diagnosis was 25.8 months (range, 8.4-99.0 months). One patient, treated with SIB, was alive at the October 2017 follow-up. Two cases of grade 5 radiation pneumonitis were registered. A GTV-PET ≤ 205 cc was predictive of late ≥ grade 2 lung toxicity, but also of better survival in stage III and IV disease: 5.9 versus 11.7 months (P = .04). A GTV-PET ≥ 473 cc was predictive of early death (P = .001).

CONCLUSIONS

Moderately hypofractionated, FDG-PET guided salvage HT in patients with progressive MPM after previous treatments showed acceptable toxicity and outcome results similar to adjuvant radiotherapy after pleurectomy/decortication, suggesting that the delay of radiotherapy is not detrimental to survival, and has the associated benefit of postponing inherent toxicity.

Induction chemotherapy, extrapleural pneumonectomy and adjuvant radiotherapy for malignant pleural mesothelioma

OBJECTIVES

While the best approach to malignant pleural mesothelioma has yet to be demonstrated, surgery remains the mainstay of treatment. We analysed a group of candidates for trimodality treatment, aiming to identify prognostic factors guiding patient selection.

METHODS

Between 2003 and 2015, 83 (31.6%) of the 283 patients with malignant pleural mesothelioma were considered for trimodality treatment to perform induction chemotherapy, extrapleural pneumonectomy and adjuvant radiotherapy. All patients underwent cisplatin-based chemotherapy. Radiotherapy was administered at a mean dose of 50.4 Gy.

RESULTS

Thirty-six patients (43.4%) had 3 cycles of chemotherapy, whereas 21 (25.3%) had more than 3. Progression to chemotherapy was observed in 10.9% (9 of 83) of patients, partial response in 30.1% (25 of 83) and stable disease in 59% (49 of 83). Sixty-three patients underwent extrapleural pneumonectomy. Fifty-five patients (87.3%) had epithelial tumour. Forty-two patients (66.7%) were in pathological Stage 3. Major complications after extrapleural pneumonectomy were observed in 28 patients (44.4%), whereas 30-day postoperative mortality was 11.1% (7/63). Radiotherapy was not administered in 24 patients (38.1%) due to major complications after surgery or patient intolerance. Two patients (3.2%) died within 90 days after the end of radiotherapy. The trimodality treatment was completed in 37 (44.6%) patients. Median overall survival was 35.6 months, with 1- and 3-year overall survival of 82% and 48% for patients who completed the trimodality treatment compared with 32% and 14% for patients who did not undergo radiotherapy.

CONCLUSIONS

Only 45% of patients completed the planned trimodality treatment, and morbidity/mortality remained high. Nonetheless, the patients who completed treatment showed good loco-regional disease control and better overall survival.

Malignant pleural mesothelioma: A retrospective analysis of clinicopathological and survival data

BACKGROUND

  The aim of this study was to analyze the clinicopathological features of malignant pleural mesothelioma (MPM) and evaluate the therapeutic measures offered to patients with MPM and their impact on survival.

METHODS

  Data was retrospectively collected from the medical records of 304 patients who presented to the Department of Clinical Oncology and Nuclear Medicine, Ain Shams University between January 2003 and December 2008.

RESULTS

  The mean age of patients was 52.1 years (range 24-87 years). One hundred and ninety patients (62.5%) came from endemic areas and/or gave history of occupational asbestos exposure. One hundred and sixty-nine patients received chemotherapy. There was a significant difference between the median survival for patients who received chemotherapy (9 months, 95% CI 7.69-10.30) and those who were offered best supportive care (2 months, 95% CI 0.09-3.91). Other factors that affected the survival negatively were: non-epithelial pathology (P= 0.001); age >50 years (P= 0.012); bad performance status (P= 0.001); non-platinum based chemotherapy (P= 0.0001); and progressive disease (P= 0.000). Cox regression analysis revealed that the factors that predicted shorter survival were patients being offered best supportive care rather than chemotherapy and progressive disease.

CONCLUSION

  MPM is a growing health problem in Egypt that needs more attention. The current analysis of data reflects the importance of maintaining a high index of suspicion to allow for early diagnosis, especially for cases that live in areas with high asbestos exposure and for people who work in occupations that expose them to asbestos as well as their family members. Prospective randomized trials comparing multimodality approaches to other forms of treatment and including quality of life assessment are warranted.

Outcomes of the Multimodal Treatment of Malignant Pleural Mesiothelioma: The Role of Surgery

Background

The treatment of malignant pleural mesothelioma (MPM) is challenging, and multimodal treatment including surgery is recommended; however, the role of surgery is debated. The treatment outcomes of MPM in Korea have not been reported. We analyzed the outcomes of MPM in the context of multimodal treatment, including surgery.

Methods

The records of 29 patients with pathologically proven MPM from April 1998 to July 2015 were retrospectively reviewed. The treatment outcomes of the surgery and non-surgery groups were compared.

Results

The overall median survival time was 10.6 months, and the overall 3-year survival rate was 25%. No postoperative 30-day or in-hospital mortality occurred in the surgery group. Postoperative complications included tachyarrhythmia (n=4), pulmonary thromboembolism (n=1), pneumonia (n=1), chylothorax (n=1), and wound complications (n=3). The treatment outcomes between the surgery and non-surgery groups were not significantly different (3-year survival rate: 31.3% vs. 16.7%, respectively; p=0.47). In a subgroup analysis, there was no significant difference in the treatment outcomes between the extrapleural pneumonectomy group and the non-surgery group (3-year survival rate: 45.5% vs. 16.7%, respectively; p=0.23).

Conclusion

Multimodal treatment incorporating surgery did not show better outcomes than non-surgical treatment. A nationwide multicenter data registry and prospective randomized controlled studies are necessary to optimize the treatment of MPM.