A systematic review and meta-analysis of surgical treatments for malignant pleural mesothelioma

Pleural mesothelioma in situ : a comprehensive review

Pleural mesothelioma is a rare and aggressive cancer that affects the pleura. In recent years, there has been increasing interest and attention in detecting and diagnosing early-stage or precancerous forms of mesothelioma because of its severe prognosis and short life expectancy at the time of diagnosis. Mesothelioma in situ represents a clear opportunity to improve and innovate the diagnostic approach and the multimodality treatment of mesothelioma: the diagnosis of pleural mesothelioma at the 'in-situ phase' means early disease detection and thus paves the way to new possible curable strategies. Since 2021, when mesothelioma in situ was finally identified and described as a new histological entity, its diagnosis and management became a challenge and the subject of ongoing research; several aspects remain open and still outstanding as regards diagnostic techniques, time and probability of progression, need for and methods of follow up, aggressive and early surgery. This narrative review aims to provide a comprehensive overview of mesothelioma in situ covering its definition, risk factors, diagnostic criteria, and tricky aspects of early detection. It also highlights its clinical significance, new perspectives, and potential future indications in the context of pleural mesothelioma multidisciplinary management.

Unleashing precision: A review of targeted approaches in pleural mesothelioma

This review delves into the intricate landscape of pleural mesothelioma (PM), emphasizing the need for nuanced therapeutic strategies. While platinum-based chemotherapy remains a cornerstone, the advent of immune checkpoint inhibitors (ICIs), notably through the Checkmate 743 trial, has reshaped treatment paradigms. Challenges persist due to patient heterogeneity and a lack of specific biomarkers. Targeting genotypic and phenotypic alterations emerges as a promising avenue, demanding precision oncology in this rare disease. CDKN2A loss, prevalent in PM, may respond to CDK4/6 inhibitors. Defects in MMR and HR suggest tailored approaches with ICI or PARP inhibitors, respectively. Ongoing trials explore novel inhibitors and promising targets like mesothelin. Implementing these strategies requires overcoming challenges in patient selection, combination therapies, biomarker identification, and cost considerations. Collaboration is crucial for transforming these insights into impactful clinical interventions, heralding the era of personalized and precision medicine for PM.

Optimal surgery for resectable malignant pleural mesothelioma in the setting of multimodality treatment

The surgical treatment of malignant pleural mesothelioma (MPM) involves procedures to achieve macroscopic complete resection, depending on the patient's condition. We reviewed the evolution of surgical approaches for resectable MPM. Since surgery is no more than a single step in the set of processes in multimodality treatment (MMT), we concluded that these procedures should give precedence to lung preservation and minimize resection whenever possible. Postoperative quality of life must be prioritized when the patient can receive appropriate adjuvant therapy.

Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma

PURPOSE

To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery.

METHODS

Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As a secondary endpoint, reported toxicity was assessed.

RESULTS

A total of 34 localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31 patients. Grade 3 side effects were experienced by 26.7% of patients and there were no grade 4 or 5 events observed. Median PFS was 19 months. Median OS was 20 months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008).

CONCLUSION

IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as a component of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

Contemporary management of mesothelioma

Pleural mesothelioma (PM) is an aggressive asbestos-associated thoracic malignancy with a median survival of 12-18 months. Due to continued asbestos use in many nations, global incidence is rising. Causes due to non-occupational, environmental exposure are also rising in many countries despite utilisation bans. For many years, platinum--pemetrexed chemotherapy was the solitary licensed therapy, but first-line combination immune checkpoint blockade has recently demonstrated improved outcomes, with both regimes tested in predominantly late-stage cohorts. In the second-line setting, single-agent nivolumab has been shown to extend survival and is now available for routine use in some regions, while second-line chemotherapy has no proven role and opportunities for clinical trials should be maximised in relapsed disease. Surgery for "technically resectable" disease has been offered for decades in many expert centres, but the recent results from the phase III MARS2 trial have challenged this approach. There remains no robustly proven standard of care for early-stage PM. The clinical trial landscape for PM is complex and increasingly diverse, making further development of specialist PM multidisciplinary teams an important priority in all countries. The observation of improving outcomes in centres that have adopted this service model emphasises the importance of high-quality diagnostics and equitable access to therapies and trials. Novel therapies targeting a range of aberrations are being evaluated; however, a better understanding of the molecular drivers and their associated vulnerabilities is required to identify and prioritise treatment targets.

A randomised phase II study of extended pleurectomy/decortication preceded or followed by chemotherapy in patients with early-stage pleural mesothelioma: EORTC 1205

BACKGROUND

The role of surgery in pleural mesothelioma remains controversial. It may be appropriate in highly selected patients as part of a multimodality treatment including chemotherapy. Recent years have seen a shift from extrapleural pleuropneumonectomy toward extended pleurectomy/decortication. The most optimal sequence of surgery and chemotherapy remains unknown.

METHODS

EORTC-1205-LCG was a multicentric, noncomparative phase 2 trial, 1:1 randomising between immediate (arm A) and deferred surgery (arm B), followed or preceded by chemotherapy. Eligible patients (Eastern Cooperative Oncology Group 0-1) had treatment-naïve, borderline resectable T1-3 N0-1 M0 mesothelioma of any histology. Primary outcome was rate of success at 20 weeks, a composite end-point including 1) successfully completing both treatments within 20 weeks; 2) being alive with no signs of progressive disease; and 3) no residual grade 3-4 toxicity. Secondary end-points were toxicity, overall survival, progression-free survival and process indicators of surgical quality.

FINDINGS

69 patients were included in this trial. 56 (81%) patients completed three cycles of chemotherapy and 58 (84%) patients underwent surgery. Of the 64 patients in the primary analysis, 21 out of 30 patients in arm A (70.0%; 80% CI 56.8-81.0%) and 17 out of 34 patients (50.0%; 80% CI 37.8-62.2%) in arm B reached the statistical end-point for rate of success. Median progression-free survival and overall survival were 10.8 (95% CI 8.5-17.2) months and 27.1 (95% CI 22.6-64.3) months in arm A, and 8.0 (95% CI 7.2-21.9) months and 33.8 (95% CI 23.8-44.6) months in arm B. Macroscopic complete resection was obtained in 82.8% of patients. 30- and 90-day mortality were both 1.7%. No new safety signals were found, but treatment-related morbidity was high.

INTERPRETATION

EORTC 1205 did not succeed in selecting a preferred sequence of pre- or post-operative chemotherapy. Either procedure is feasible with a low mortality, albeit consistent morbidity. A shared informed decision between surgeon and patient remains essential.

Anaesthetic and perioperative considerations for extrapleural pneumonectomy and extended pleurectomy/decortication: a scoping review protocol

INTRODUCTION

Extrapleural pneumonectomy (EPP) and extended pleurectomy/decortication (ePD) are surgical cytoreductive techniques aimed at achieving macroscopic resection in malignant pleural tumours such as pleural mesothelioma, non-mesothelioma pleural malignancies such as thymoma and sarcoma, and rarely for pleural tuberculosis, in a more limited fashion. Despite extensive studies on both surgical techniques and consequences, a significant knowledge gap remains regarding how best to approach the perioperative anaesthesia challenges for EPP and ePD.It is unknown if the risk stratification processes for such surgeries are standardised or what types of functional and dynamic cardiac and pulmonary tests are employed preoperatively to assist in the perioperative risk stratification. Further, it is unknown whether the types of anaesthesia and analgesia techniques employed, and the types of haemodynamic monitoring tools used, impact on outcomes. It is also unknown whether individualised haemodynamic protocols are used to guide the rational use of fluids, vasoactive drugs and inotropes.Finally, there is a dearth of evidence regarding how best to monitor these patients postoperatively or what the most effective enhanced recovery protocols are to best mitigate postoperative complications and accelerate hospital discharge. To increase our knowledge of the perioperative and anaesthetic treatment for patients undergoing EPP/ePD, this scoping review attempts to synthesise the literature and identify these knowledge gaps.

METHODS AND ANALYSIS

This scoping review will be conducted in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Extension for Scoping Review Protocols methodology. Electronic databases, OVID Medline, EMBASE and the Cochrane Library, will be systematically searched for relevant literature corresponding to EPP or ePD and perioperative or anaesthetic management. Data will be analysed and summarised descriptively and organised according to the three perioperative stages: preoperative, intraoperative and postoperative factors in clinical care.

ETHICS AND DISSEMINATION

Ethics approval was not required. The findings will be disseminated through professional networks, conference presentations and publications in scientific journals.

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.

Multimodal Treatment of Pleural Mesothelioma with Cytoreductive Surgery and Hyperthermic Intrathoracic Chemotherapy: Impact of Additive Chemotherapy

Cytoreductive surgery (CRS) combined with hyperthermic intrathoracic chemoperfusion (HITOC) is a promising treatment strategy for pleural mesothelioma (PM). The aim of this study was to evaluate the impacts of this multimodal approach in combination with systemic treatment on disease-free survival (DFS) and overall survival (OS). In this retrospective multicenter study, clinical data from patients after CRS and HITOC for PM at four high-volume thoracic surgery departments in Germany were analyzed. A total of 260 patients with MPM (220 epithelioid, 40 non-epithelioid) underwent CRS and HITOC as part of a multimodal treatment approach. HITOC was administered with cisplatin alone (58.5%) or cisplatin and doxorubicin (41.5%). In addition, 52.1% of patients received neoadjuvant and/or adjuvant chemotherapy. The median follow-up was 48 months (IQR = 38 to 58 months). In-hospital mortality was 3.5%. Both the resection status (macroscopic complete vs. incomplete resection) and histologic subtype (epithelioid vs. non-epithelioid) had significant impacts on DFS and OS. In addition, adjuvant chemotherapy (neoadjuvant/adjuvant) significantly increased DFS (p = 0.003). CRS and HITOC within a multimodal treatment approach had positive impacts on the survival of patients with epithelioid PM after macroscopic complete resection. The addition of chemotherapy significantly prolonged the time to tumor recurrence or progression.

Updates in Management of Malignant Pleural Mesothelioma

OPINION STATEMENT

Malignant pleural mesothelioma (MPM) is an aggressive asbestos-associated thoracic malignancy that is usually incurable. As demonstrated in the landmark MARS2 trial, surgical resection does not improve survival outcomes and its role in managing MPM is limited. Whilst platinum-pemetrexed chemotherapy in combination with bevacizumab was the standard first-line approach for unresectable disease, landmark phase 3 trials have now established the role of immune checkpoint inhibitors (CPIs) in the upfront management of unresectable disease: either nivolumab-ipilimumab or carboplatin-pemetrexed-pembrolizumab. Patient selection for optimal strategy remains an ongoing question. For relapsed disease novel genomic-based therapies targeting a range of aberrations including losses of the tumour suppressor genes BAP1, CDKN2A and NF2, are being evaluated. Nonetheless, the future of MPM therapeutics holds promise. Here we overview current treatment strategies in the management of MPM.

Extensive Skeletal Muscle Metastases in Malignant Pleural Mesothelioma Detected by FDG PET/CT

Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor originating from pleural mesothelial cells. Distant skeletal muscle metastasis is rare in MPM. A 54-year-old woman was diagnosed with epithelioid MPM and treated with surgery, chemotherapy, and radiotherapy 2 years ago. During follow-up, diffuse irregular pleural thickening with focal chest wall invasion in the right hemithorax and two small pleural thickenings in the left hemithorax were seen on control diagnostic contrast-enhanced computed tomography (CECT). Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (FDG PET/CT) imaging was performed as part of restaging. PET showed diffusely increased FDG uptake in the recurrent right pleural tumor, and two hypermetabolic small metastatic foci in the contralateral pleura. In addition, multiple hypermetabolic areas of various sizes in various skeletal muscle localizations, suggestive of extensive muscle metastases were noted. Histopathologic study confirmed metastatic epithelioid MPM. FDG PET/CT revealed multiple muscle metastases which were not observed on earlier CECT and contributed to the visualization of more extensive metastatic involvements in the presented case with MPM. FDG PET/CT can detect rarely seen skeletal muscle metastases that are not visualized on diagnostic CT, and provides more accurate restaging of MPM.

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.

Cytoreductive surgery with hyperthermic intrathoracic chemotherapy for malignant pleural mesothelioma: a systematic review

INTRODUCTION

Cytoreductive surgery has been used a part of multimodality treatment in patients with malignant pleural mesothelioma (MPM). The residual microscopic disease that remains will lead to disease progression in the majority of patients. Delivery of hyperthermic intrathoracic chemotherapy at the time of surgery has been used to address this microscopic disease, however it's effect and place in the multimodality treatment sphere is unknown. The aim of this systematic review was to assess the effect of surgery and hyperthermic intrathoracic chemotherapy in patients with MPM on overall survival and disease-free interval.

METHODS

Ovid MEDLINE, Embase, Web of Science and the Cochrane Database of Systematic Reviews were searched from database inception through to June 2021. Studies reporting overall survival and/or disease-free interval in patients with MPM undergoing cytoreductive surgery with hyperthermic intrathoracic chemotherapy were considered. Study quality was assessed using the Newcastle-Ottawa Scale. A narrative review was performed.

RESULTS

Fifteen studies were eligible for inclusion comprising 598 patients. Surgery with hyperthermic intrathoracic chemotherapy was associated with a median overall survival and disease-free interval ranging from 11 to 75 months and 7.2 to 57 months, respectively. These appeared to be superior to patients not receiving hyperthermic intrathoracic chemotherapy (overall survival: 5-36 months and disease-free interval: 12.1-21 months). A higher dose of hyperthermic intrathoracic chemotherapy was associated with an improvement in overall survival compared with a lower dose: 18-31 months versus 6-18 months, respectively. The most common morbidity was atrial fibrillation followed by renal complications.

CONCLUSION

Surgery with hyperthermic intrathoracic chemotherapy offers a safe and effective therapy with an improvement in disease-free interval and overall survival, particularly when hyperthermic intrathoracic chemotherapy is administered at a higher dose.

PROSPERO REGISTRATION NUMBER

CRD42019129002.

Malignant Pleural Mesothelioma: Preliminary Toxicity Results of Adjuvant Radiotherapy Hypofractionation in a Prospective Trial (MESO-RT)

Malignant Pleural Mesothelioma (MPM) is a rare malignancy with an overall poor prognosis. The standard therapeutic strategy in early-stage disease is trimodality therapy. In this publication, we report the preliminary toxicity results of the first 20 patients treated with accelerated hypofractionated radiotherapy. Between July 2017 to June 2019, 20 MPM patients were enrolled and treated with accelerated hypofractionated radiotherapy using helical tomotherapy and intensity-modulated arc therapy. The prescription dose was 30 Gy in five daily fractions, while an inhomogeneous dose escalation to 40 Gy was prescribed based solely upon the presence of gross residual tumor. Only one case of G3 toxicity was reported, which was a bilateral pneumonitis that occurred two years after treatment probably due to superinfection. Median Time to Progression reached 18.2 months while one- and three-year Overall Survival rates were 85% (95% CI:60.4-94.9) and 49.5% (95% CI:26.5-68.9), respectively. Treatment of the intact lung with pleural intensity-modulated arc irradiation is a novel treatment strategy that appears to be safe, feasible, and without a high grade of lung toxicity. Survival rates and Time to Progression are encouraging.

Mesothelioma Due to Workplace Exposure: A Comprehensive Bibliometric Analysis of Current Situation and Future Trends

Background: This article provides an overview of the current status and research progress of mesothelioma. Methods: A total of 2638 documents published from 1 January 2004 to 30 November 2022 were retrieved from the Web of Science Core Collection and analyzed via Microsoft Office Excel 2019, VOSviewer 1.6.18, and Tableau 2022.2. Results: There was an obvious increase in the number of publications regarding mesothelioma in the last 18 years, with the United States dominating the research field with 715 publications and 23,882 citations, while the University of Turin contributed the most (118). Occupational & Environmental Medicine was the most popular journal (80), with Corrado Magnani being the most prolific author (52) and Michele Carbone obtaining the most citations (4472). "Oncology" and "Health Science of Environment & Occupation" were the two main subjects, while the keywords "asbestos", "lung cancer", "gene expression", "apoptosis", "survival", and "cisplatin" were the most popular. Conclusions: The containment of mesothelioma calls for more participation from low- and middle-income countries, and further attention needs to be paid to clinical research.

Long-term outcomes and risk factors of residual thoracic spaces after pleurectomy/decortication for mesothelioma

OBJECTIVES

The residual thoracic spaces (RTS) after pleurectomy/decortication (P/D) remain unexplored to date. Hence, this study aims to examine the details and risk factors of RTS during the 3 post-P/D months.

METHODS

We retrospectively examined patients who underwent neoadjuvant chemotherapy, followed by P/D for malignant pleural mesothelioma from September 2012 to December 2020. The RTS group included cases of residual thoracic cavity unaccompanied by pleural effusion on 3 postoperative months computed tomography. We determined risk factors for RTS using univariable and multivariable analyses.

RESULTS

Of 170 patients examined, 58 (34.1%) were in the RTS group and 112 (65.9%) in the non-RTS group. In the RTS group, 43 patients recovered from RTS during the follow-up period; 4 patients developed chronic fistular empyema, while 2 required fenestration and 2 were thoracoscopic debridement. Besides, 11 patients exhibited RTS continuously. The univariable analysis revealed that compared with the non-RTS group, the RTS group reported a significantly longer postoperative air leak (>7 days; P < 0.01) and right P/D (P = 0.04). The multivariable analysis demonstrated that longer postoperative air leak (>7 days) remained a risk factor for RTS (odds ratio 2.5, 95% confidence interval: 1.3-4.9, P < 0.01).

CONCLUSIONS

RTS was a postoperative event that frequently observed in patients undergoing P/D. Overall, the current study findings suggest longer postoperative air leak (>7 days) as a significant risk factor for RTS.

Survival analysis and development of a prognostic nomogram for patients with malignant mesothelioma in different anatomic sites

Background

Malignant mesothelioma (MMe) is a rare and fatal cancer with a poor prognosis. Our study aimed to compare the overall survival (OS) of MMe patients across various sites and develop a prognostic model to provide a foundation for individualized management of MMe patients.

Methods

From the Surveillance, Epidemiology, and End Results (SEER) database, 1,772 individuals with malignant mesothelioma (MMe) were identified. The X-tile software was used to identify the optimal cut-off point for continuous variables. The Kaplan–Meier method was employed to compare the survival of MMe across different sites. The Cox proportional hazards model was applied to identify the independent risk factors of overall survival (OS) and a nomogram was constructed.

Results

In the survival analysis, MMe originating from the reproductive organs and hollow organs showed a relatively better prognosis than those originating from soft tissue, solid organs, and pleura. Age, gender, location, histological type, grade of differentiation, extent of disease, lymph node status, lymph node ratio (LNR), and chemotherapy were all found to be independent risk variables for the prognosis of MMe patients (P&lt;0.05) in a multivariate Cox analysis and were included in the construction of nomogram. In the training and testing sets, the C-index of the nomogram was 0.701 and 0.665, respectively, and the area under the ROC curve (AUROC) of the 1-, 3-, and 5-year overall survival rate was 0.749, 0.797, 0.833 and 0.730, 0.800, 0.832, respectively. The calibration curve shows that the nomogram is well-calibrated.

Conclusions

This is the first research to examine the prognosis of MMe patients based on the location. However, previous studies often focused on malignant pleural mesothelioma or malignant peritoneal mesothelioma with high incidence. Furthermore, a nomograph with good prediction efficiency was established according to the variables that influence patient survival outcomes, which provides us with a reference for clinical decision-making.

Systematic Review and Meta-Analysis of Pleurectomy/Decortication versus Extrapleural Pneumonectomy in the Treatment of Malignant Pleural Mesothelioma

Objective: Malignant pleural mesothelioma (MPM) is a rare and aggressive malignant cancer for which there are poor treatment options. Extrapleural pneumonectomy (EPP) and pleurectomy decortication (P/D) are the two most used surgical procedures in patients with resectable disease. We reviewed the available literature in order to compare the overall survival and postoperative complications of EPP and P/D and to provide evidence for the best procedure in the treatment of MPM. Methods: We performed a systematic review of the literature, including studies from August 2018 to May 2022. The primary outcome was 5-year overall survival (OS) and the secondary outcomes were 30-day mortality, 90-day mortality and peri-operative complications. Results: Thirteen studies were considered, including a total of 1624 patients treated with EPP and 2147 treated with P/D. The estimated pooled HR showed a significant lower hazard for P/D compared to EPP in terms of OS (HR = 0.76; 95% CI from 0.62 to 0.94; p < 0.001). In 12 studies, the risk for 30-day mortality was lower for patients treated with P/D (RR = 0.49; 95% CI from 0.31 to 0.76; p = <0.01), whereas only five studies reported 90-day mortality, and no statistically significant difference between EPP and P/D was found (RR = 0.71; 95% CI from 0.47 to 1.07; p = 0.10). The OS restricted mean survival time difference meta-analysis (RMSDT) confirms the superior survival of P/D on the EPP, a superiority that increases from 0.54 months at one year to 4.23 at five years. The incidence of postoperative empyema, atrial fibrillation, bleeding and bronchopleural fistula was significantly increased in the EPP group except for prolonged air leakage, which is only characteristic of P/D. Conclusions: Using two different statistical methods, this meta-analysis suggests that long-term survival after surgical treatment for resectable MPM is greater for patients undergoing P/D. Long-term survival had never been previously analyzed with appropriate tests; on the contrary, our result is consistent with the previous meta-analyses and reinforces the evidence of lower 30-day mortality and the prevalence of postoperative complications in P/D versus EPP patients. The recent introduction of innovative therapeutic schemes, both adjuvant and neoadjuvant therapy, keeps the discussion on surgical strategy open and will require new studies.

Pleural decortication and hyperthermic intrathoracic chemotherapy for pseudomyxoma

Aim: Pleural dissemination of pseudomyxoma peritonei (PMP) is an extremely rare diagnosis, for which no standard therapy is available.Methods: We describe the successful treatment of a 67-year-old male diagnosed with left-sided intrapleural dissemination of PMP (low-grade appendiceal mucinous neoplasm), 2 years after treatment of abdominal PMP with cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy. Treatment consisted of extended pleural decortication (ePD) and oxaliplatin-based hyperthermic intrathoracic chemotherapy (HITHOC). The patient is doing well without complications or signs of recurrence, 26 months after thoracic surgery.Conclusion: ePD in combination with HITHOC is a valuable treatment for thoracic PMP.

Feasibility and safety of extended pleurectomy/decortication for malignant pleural mesothelioma. A single group experience

Surgery is part of a multimodal therapeutic approach to malignant pleural mesothelioma (MPM) although its real beneficial effect is still controversial. The optimal precise sequence of treatments within the trimodality is unclear, and should be decided upon a multidisciplinary consensus for each individual patient. Here, we analyzed the perioperative data of 19 MPM patients who underwent extended pleurectomy/decortication (EPD) with curative intent. The mean age at diagnosis was 67 years; 11 males and eight females. Ten patients were diagnosed with MPM via medical thoracoscopy (MT), and nine via video‐assisted thoracoscopic surgery (VATS). The vast majority of cases harbored epitheliod forms. We compared neoadjuvant chemotherapy (NCT) followed by surgery (11 cases) versus surgery followed by adjuvant chemotherapy (ACT, 8 cases) within a 3‐year period. All patients had extended pleurectomy/decortication and none had an extended pneumonectomy. Analysis of survival curves suggested that the short‐term outcomes are better with upfront EDP followed by ACT if compared to EDP preceded by NCT. Although limited, the data highlighted the safety and feasibility of EPD, with manageable postoperative complications and no major burden for the patients.

Training and validation of a knowledge-based dose-volume histogram predictive model in the optimisation of intensity-modulated proton and volumetric modulated arc photon plans for pleural mesothelioma patients

BACKGROUND

To investigate the performance of a narrow-scope knowledge-based RapidPlan (RP) model for optimisation of intensity-modulated proton therapy (IMPT) and volumetric modulated arc therapy (VMAT) plans applied to patients with pleural mesothelioma. Second, estimate the potential benefit of IMPT versus VMAT for this class of patients.

METHODS

A cohort of 82 patients was retrospectively selected; 60 were used to "train" a dose-volume histogram predictive model; the remaining 22 provided independent validation. The performance of the RP models was benchmarked, comparing predicted versus achieved mean and near-to-maximum dose for all organs at risk (OARs) in the training set and by quantitative assessment of some dose-volume metrics in the comparison of the validation RP-based data versus the manually optimised training datasets. Treatment plans were designed for a prescription dose of 44 Gy in 22 fractions (proton doses account for a fixed relative biological effectiveness RBE = 1.1).

RESULTS

Training and validation RP-based plans resulted dosimetrically similar for both VMAT and IMPT groups, and the clinical planning aims were met for all structures. The IMPT plans outperformed the VMAT ones for all OARs for the contra-lateral and the mean and low dose regions for the ipsilateral OARs. Concerning the prediction performance of the RP models, the linear regression for the near-to-maximum dose resulted in Dachieved = 1.03Dpredicted + 0.58 and Dachieved = 1.02Dpredicted + 1.46 for VMAT and IMPT, respectively. For the mean dose it resulted: Dachieved = 0.99Dpredicted + 0.34 and Dachieved = 1.05Dpredicted + 0.27 respectively. In both cases, the linear correlation between prediction and achievement is granted with an angular coefficient deviating from unity for less than 5%. Concerning the dosimetric comparison between manual plans in the training cohort and RP-based plans in the validation cohort, no clinical differences were observed for the target volumes in both the VMAT and IMPT groups. Similar consistency was observed for the dose-volume metrics analysed for the OAR. This proves the possibility of achieving the same quality of plans with manual procedures (the training set) or with automated RP-based methods (the validation set).

CONCLUSION

Two models were trained and validated for VMAT and IMPT plans for pleural mesothelioma. The RP model performance resulted satisfactory as measured by the agreement between predicted and achieved (after full optimisation) dose-volume metrics. The IMPT plans outperformed the VMAT plans for all the OARs (with different intensities for contra- or ipsilateral structures). RP-based planning enabled the automation of part of the optimisation and the harmonisation of the dose-volume results between training and validation. The IMPT data showed a systematic significant dosimetric advantage over VMAT. In general, using an RP-based approach can simplify the optimisation workflow in these complex treatment indications without impacting the quality of plans.

Single-Center 20-Year Experience in Surgical Treatment of Malignant Pleural Mesothelioma

Objectives: We examined a series of malignant pleural mesothelioma (MPM) patients who consecutively underwent surgery in our institution during the last 20 years. Across this period, we changed our surgical approach to MPM, adopting extended pleurectomy and decortication (eP/D) instead of extrapleural pneumonectomy (EPP). In this study, we compare the perioperative outcomes and long-term survival of patients who underwent EPP vs. eP/D. Methods: A retrospective analysis was carried out of all the MPM patients identified from our departmental database who underwent EPP or P/D from 2000 to 2021. Clavien−Dindo criteria was adopted to score postoperative complications, while Kaplan−Meier methods and a Cox multivariable analysis were used to perform the survival analysis. Results: Of 163 patients, 78 (48%) underwent EPP and 85 (52%) eP/D. Induction chemotherapy was significantly administrated more often in the eP/D group (88% vs. 51%). Complete trimodality treatment including induction chemotherapy, radical surgery, and adjuvant radiotherapy was administered in 74% of the eP/D group versus 32% of the EPP group (p < 0.001). The postoperative morbidity rate was higher in the eP/D group (54%) compared to the EPP group (36%) (p = 0.02); no statistically significant differences were identified concerning major complications (EPP 43% vs. eP/D 24%, p = 0.08). No statistical differences were identified in 30-day mortality, 90-day mortality, median disease-free, and overall survival statistics between the two groups. The Cox multivariable analysis confirmed no induction chemotherapy (HR, 0.5; p = 0.002), RDW (HR, 1.08; p = 0.02), and the presence of pathological nodal disease (HR, 1.99; p = 0.001) as factors associated with worse survival in the entire series. Conclusions: Our data support that eP/D is a well-tolerated procedure allowing the implementation of a trimodality strategy (induction chemotherapy, surgery, and radiotherapy) in most MPM patients. When eP/D is offered in this setting, the oncological results are comparable to EPP. To obtain the best oncological results, the goal of surgical resection should be macroscopic complete resection (R0) in carefully selected patients (clinical N0).

NFE2L3 as a Novel Biomarker Associated With IL-2/STAT5/NLRP3 Signaling Pathway in Malignant Pleural Mesothelioma and Other Cancers

Background: Malignant pleural mesothelioma (MPM) is a malignant tumor originating from pleural mesothelial cells and has a high mortality rate worldwide. With the advent of immunotherapy in MPM treatment, there is an urgent need to elucidate the immune-related mechanisms in this caner.

Methods: Single-sample gene set enrichment analysis (ssGSEA) was used to score the immunocytes infiltration of data from different database sources. Identification of immunocyte-related genes was performed with weighted gene co-expression network analysis (WGCNA), differentially expressed genes (DEGs) analysis, and correlation analysis. Pan-caner analysis was performed using “DiffExp” and “Correlation” modules in TIMER.

Results: T-helper 2 (Th2) cell was found to be a poor prognostic factor for patients with MPM. Then a transcription factor, NFE2L3, was identified as a biomarker that showed a strong positive correlation with Th2 cell infiltration, and was highly expressed in MPM tissues and was related to the poor prognosis of these patients. At the same time, multiple NFE2L3 methylation sites were negatively correlated with Th2 cell infiltration, and patients with a high degree of methylation enjoy a better prognosis. Pan-caner analysis indicated that NFE2L3 might promote the differentiation of Th2 cells through the IL-2/STAT5/NLRP3 signaling pathway in MPM and many other cancers.

Conclusion: We believe that NFE2L3 can serve as a potential biomarker related to the diagnosis and prognosis of patients with MPM, and speculate that NFE2L3 could promote Th2 cell differentiation via IL-2/STAT5/NLRP3 signaling pathway in MPM and many other cancers.

Current State of Pleural-Directed Adjuncts Against Malignant Pleural Mesothelioma

Multimodality therapy including surgical resection is the current paradigm in treating malignant pleural mesothelioma (MPM), a thoracic surface cancer without cure. The main limitation of all surgical approaches is the lack of long-term durability because macroscopic complete resection (R1 resection) commonly predisposes to locoregional relapse. Over the years, there have been many studies that describe various intrapleural strategies that aim to extend the effect of surgical resection. The majority of these approaches are intraoperative adjuvants. Broadly, there are three therapeutic classes that employ diverse agents. The most common, widely used group of adjuvants are comprised of direct therapeutics such as intracavitary chemotherapy (± hyperthermia). By comparison, the least commonly employed intrathoracic adjuvant is the class comprised of drug-device combinations like photodynamic therapy (PDT). But the most rapidly evolving (new) class with much potential for improved efficacy are therapeutics delivered by specialized drug vehicles such as a fibrin gel containing cisplatin. This review provides an updated perspective on pleural-directed adjuncts in the management of MPM as well as highlighting the most promising near-term technology breakthroughs.

Downregulation of FTL decreases proliferation of malignant mesothelioma cells by inducing G1 cell cycle arrest

Pleural malignant mesothelioma is a malignant tumor with a poor prognosis that is strongly associated with asbestos exposure during its development. Because there is no adequate treatment for malignant mesothelioma, investigation of its molecular mechanism is important. The ferritin light chain (FTL) is a subunit of ferritin, and its high expression in malignant tumors, including malignant mesothelioma, has recently been reported; however, its role in malignant mesothelioma is unclear. The purpose of the present study was to clarify the function of FTL in malignant mesothelioma. The expression levels of FTL in malignant mesothelioma were examined using the Cancer Cell Line Encyclopedia database and our previous data. The short interfering (si)RNA against FTL was transfected into two mesothelioma cell lines, ACC-MESO-1 and CRL-5915, and functional analysis was performed. Expression of p21, p27, cyclin-dependent kinase 2 (CDK2) and phosphorylated retinoblastoma protein (pRb) associated with the cell cycle were examined as candidate genes associated with FTL. The expression levels of the FTL mRNA were higher in malignant mesothelioma compared with other tumors in the Cancer Cell Line Encyclopedia database, and among other genes in our previous study. Reverse transcription-quantitative PCR and western blotting demonstrated suppression of FTL expression in two cell lines transfected with FTL siRNA compared with cells transfected with negative control (NC) siRNA. In the two cell lines transfected with FTL siRNA, proliferation was significantly suppressed, and cell cycle arrest was observed in the G₁ phase. The levels of p21 and p27 were increased, while those of CDK2 and pRb were decreased compared with NC. However, no significant differences in invasion and migration ability were revealed between FTL siRNA-transfected cells and NC. In conclusion, FTL may increase the proliferative capacity of malignant mesothelioma cells by affecting p21, p27, CDK2 and pRb, and promoting the cell cycle at the G₁ phase.

An Update on Emerging Therapeutic Options for Malignant Pleural Mesothelioma

The treatment paradigm for malignant pleural mesothelioma (MPM) has changed little in the last 18 years. Radical intent treatment, consisting of surgical resection, radiotherapy and chemotherapy, has been offered to a highly select few; however, there is little randomised evidence to validate this approach. Prior to 2020 chemotherapy with platinum and an anti-folate was the only intervention with randomised evidence to demonstrate improved overall survival (OS) in MPM. No systemic therapy had been demonstrated to improve OS in the second line setting until 2020. The publication of the Checkmate 743 trial in 2021 demonstrated a survival benefit of combination immunotherapy over standard chemotherapy in newly diagnosed patients with MPM. This finding was shortly followed by the CONFIRM trial which demonstrates a modest but significant survival benefit of second line nivolumab versus placebo in patients having previously received standard chemotherapy. The results of these trials, recent biomarker directed therapy and chemotherapy adjuncts are discussed within this review. The integration of immunotherapy for the few patients in whom radical surgical therapy is intended is currently the subject of clinical trials and offers the prospect of improving outcomes in this rare but devastating disease.

Current Management and Future Perspective in Pleural Mesothelioma

Pleural mesothelioma is an aggressive malignancy arising from pleural mesothelial cell lining, predominantly associated with prior exposure to asbestos. The ban on asbestos use has led to its lower incidence in many countries, but globally the disease burden is expected to rise. Therefore, well-planned research is needed to develop more effective, tolerable and affordable drugs. The development of novel treatment has been too slow, with only two regimens of systemic therapy with robust phase 3 data approved formally to date. The treatment scenario for resectable disease remains controversial. However, recent developments in the understanding of disease and clinical trials have been encouraging, and may add better treatment options in the coming years. In this review, we discuss the current treatment options for pleural mesothelioma and shed light on some recent studies and ongoing trials.

Quality of Life Is Not Deteriorated After Extrapleural Pneumonectomy vs. (Extended) Pleurectomy/Decortication in Patients With Malignant Pleural Mesothelioma

Background: Extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma (MPM) is highly abandoned due to high morbidity and mortality rates and impaired quality of life (QoL). However, there are still rare indications for this intervention. The aim of this longitudinal prospective study was to monitor QoL and lung function in patients undergoing EPP and compare the outcomes with extended pleurectomy/decortication [(E)PD]. Methods: Between June 2013 and June 2017, 42 patients underwent induction chemotherapy followed by either EPP (n = 7) or (E)PD (n = 35). All patients filled out the EORTC QLC-C15-PAL, -LC13, and SF-36 self-rating questionnaires pre-operatively, 6 weeks and 4 months after the operation. Additionally, lung function was measured pre-operatively and 4 months post-operatively. Results: We observed no significant differences in all QoL categories (general global health, pain, and dyspnea) between both surgical procedures, over the whole observation period. Moreover, a general tendency toward restoration of the pre-operative QoL status was documented at 4 months after the both operations. Forced expiratory volume in 1 s (FEV1) showed a significant decrease after surgery in both the groups [EPP group p = 0.06 and (E)PD group p < 0.001]; also, the forced volume vital capacity (FVC) significantly decreased (EPP group p = 0.046 P/D group <0.001). Diffusion capacity did not show significant changes. Conclusion: According to these results, QoL is no longer severely impaired after EPP compared with EPD, and therefore should not be used as an argument against EPP in principle. However, indication has to be carefully evaluated for each patient.

Downregulation of lncRNA PVT1 inhibits proliferation and migration of mesothelioma cells by targeting FOXM1

Malignant mesothelioma is a highly aggressive tumor, and an effective strategy for its treatment is not yet available. Long non-coding RNAs (lncRNAs) have been reported to be associated with various biological processes, including the regulation of gene expression of cancer-related pathways. Among various lncRNAs, plasmacytoma variant translocation 1 (PVT1) acts as a tumor promoter in several human cancers, but its mechanism of action has not yet been elucidated. Increased PVT1 expression was identified in ACC-MESO-1, ACC-MESO-4, CRL-5915, and CRL-5946 mesothelioma cell lines. PVT1 expression was investigated in mesothelioma cell lines by reverse transcription-quantitative polymerase chain reaction and its functional analysis by cell proliferation, cell cycle, cell migration, and cell invasion assays, as well as western blot analysis of downstream target genes. Knockdown of PVT1 expression in these cell lines by small interfering RNA transfection resulted in decreased cell proliferation and migration and increased the proportion of cells in the G2/M phase. The results of reverse transcription-quantitative polymerase chain reaction analysis revealed that PVT1 knockdown in mesothelioma cell lines caused the downregulation of Forkhead box M1 (FOXM1) expression, while the results of western blot analysis revealed that this knockdown reduced FOXM1 expression at the protein level. In addition, combined knockdown of PVT1 and FOXM1 decreased the proliferation of mesothelioma cell lines. In conclusion, PVT1 and FOXM1 were involved in the proliferation of cancer cells. Therefore, PVT1-FOXM1 pathways may be considered as candidate targets for the treatment of malignant mesothelioma.

Induction Chemotherapy Followed by Pleurectomy Decortication and Hyperthermic Intraoperative Chemotherapy (HITHOC) for Early-Stage Epitheliod Malignant Pleural Mesothelioma-A Prospective Report

Malignant pleural mesothelioma (MPM) is an aggressive disease with poor prognosis and the current treatment for early-stage MPM is based on a multimodality therapy regimen involving platinum-based chemotherapy preceding or following surgery. To enhance the cytoreductive role of surgery, some peri- or intra-operative intracavitary treatments have been developed, such as hyperthermic chemotherapy, but long-term results are weak. The aim of this study was to report the post-operative results and mid-term outcomes of our multimodal intention-to-treat pathway, including induction chemotherapy, followed by surgery and Hyperthermic Intraoperative THOracic Chemotherapy (HITHOC) in the treatment of early-stage epithelioid MPM. Since 2017, stage I or II epithelioid MPM patients have been inserted in a surgery-based multimodal approach comprising platinum-based induction chemotherapy, followed by pleurectomy and decortication (P/D) and HITHOC with cisplatin. The Kaplan–Meier method was used to estimate overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS). During the study period, n = 65 patients affected by MPM were evaluated by our institutional Multidisciplinary Tumour Board; n = 12 patients with stage I-II who had no progression after induction chemotherapy underwent P/D and HITHOC. Post-operative mortality was 0, and complications developed in n = 7 (58.3%) patients. The median estimated OS was 31 months with a 1-year and 3-year OS of 100% and 55%, respectively. The median PFS was 26 months with 92% of a 1-year PFS, whereas DFS was 19 months with a 1-year DFS rate of 83%. The multimodal treatment of early-stage epithelioid MPM, including induction chemotherapy followed by P/D and HITHOC, was well tolerated and feasible with promising mid-term oncological results.

A novel PDX modeling strategy and its application in metabolomics study for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare and aggressive carcinoma located in pleural cavity. Due to lack of effective diagnostic biomarkers and therapeutic targets in MPM, the prognosis is extremely poor. Because of difficulties in sample extraction, and the high rate of misdiagnosis, MPM is rarely studied. Therefore, novel modeling methodology is crucially needed to facilitate MPM research.

METHODS

A novel patient-derived xenograft (PDX) modeling strategy was designed, which included preliminary screening of patients with pleural thickening using computerized tomography (CT) scan, further reviewing history of disease and imaging by a senior sonographer as well as histopathological analysis by a senior pathologist, and PDX model construction using ultrasound-guided pleural biopsy from MPM patients. Gas chromatography-mass spectrometry-based metabolomics was further utilized for investigating circulating metabolic features of the PDX models. Univariate and multivariate analysis, and pathway analysis were performed to explore the differential metabolites, enriched metabolism pathways and potential metabolic targets.

RESULTS

After screening using our strategy, 5 out of 116 patients were confirmed to be MPM, and their specimens were used for modeling. Two PDX models were established successfully. Metabolomics analysis revealed significant metabolic shifts in PDX models, such as dysregulations in amino acid metabolism, TCA cycle and glycolysis, and nucleotide metabolism.

CONCLUSIONS

To sum up, we suggested a novel modeling strategy that may facilitate specimen availability for MM research, and by applying metabolomics in this model, several metabolic features were identified, whereas future studies with large sample size are needed.

Malignant Pleural Mesothelioma Nodal Status: Where Are We at?

Due to the lack of both prospective trial and high-volume retrospective studies, the management of clinical N+ malignant pleural mesothelioma (MPM) patients remains highly debated. Node positive patients show poor survival compared with node-negative ones; thus, lymph node staging appears crucial in determining treatment strategy. Notwithstanding the improvement in pre-treatment staging and the update on lymph node classification in the 8th edition of TNM, several open controversies remain on N parameter. How should we stage suspected N+ patients? How should we treat node positive patients? Which is the definition of a “resectable patient”? Is the site or the number the main prognostic factor for node positive patients? The aim of our narrative review is to analyse the existing relevant literature on lymph node status in MPM.

Extended Pleurectomy/Decortication for Malignant Pleural Mesothelioma: Humanitas's Experience

BACKGROUND

We analysed a series of malignant pleural mesothelioma (MPM) patients who consecutively underwent extended Pleurectomy/Decortication (eP/D) in a centre with a high level of thoracic surgery experience (IRCCS Humanitas Research Hospital) to explore postoperative morbidity and mortality, pattern of recurrence and survival.

METHODS

A retrospective analysis was performed on MPM patients underwent eP/D in our centre from 2010 to 2021. All patients were identified from our departmental database. Postoperative complications were scored according to Clavien-Dindo criteria. Survival analysis was performed by the Kaplan-Meier methods and Cox multivariable analysis.

RESULTS

Eighty-five patients underwent extended pleurectomy decortication (eP/D) during study period. Macroscopical residual disease (R2) was reported in one case. A neoadjuvant chemotherapy regiment was administrated in 88% of the surgical cohort. A complete trimodality treatment including induction with platinum agents and pemetrexed, radical cytoreductive surgery and volumetric modulated arc therapy technology (VMAT) could be administered in 63 patients (74%). Postoperative morbidity rate was 54.11%, major complications (defined as Clavien-Dindo ≥ 3) were reported in 11 patients (12.9%). Thirty-day mortality and 90-day mortality were, respectively, 2.35% and 3.53%. Median disease-free and overall survival were, respectively, 13.7 and 25.5 months. The occurrence of major complications (Clavien-Dindo ≥ 3), operative time, pT3-T4, pathological node involvement (pN+) were prognostic factors associated with worse survival.

CONCLUSIONS

In our experience, eP/D is a well-tolerated procedure with acceptable mortality and morbidity, allowing for the administration of trimodality regimens in most patients. eP/D offered in a multimodality treatment setting have satisfactory long term oncological results. To obtain best oncological results the goal of surgery should be macroscopic complete resection in carefully selected patients (clinical N0).

Ki67 (MIB-1) as a Prognostic Marker for Clinical Decision Making Before Extended Pleurectomy Decortication in Malignant Pleural Mesothelioma

Introduction

The role of surgery for early stage malignant pleural mesothelioma (MPM) remains controversial. Current expert opinion is only to treat patients surgically as part of multimodality therapy. It is still challenging to identify patients who will not benefit from surgery. We specifically evaluated tumor-related parameters in combination with clinical parameters to identify prognostic markers for survival.

Methods

Clinical data of 27 consecutive patients with MPM treated with extended pleurectomy and decortication within a multimodality approach were collected and analyzed. Several tumor (immuno-)histopathologic characteristics were determined on resected tumor material, among which MTAP and Ki67 (MIB-1). Univariable and multivariable analyses served to correlate clinical and tumor-related parameters to overall survival (OS) and progression-free survival (PFS).

Results

The median PFS (mPFS) was 15.3, and the median OS (mOS) was 26.5 months. Patients with a Ki67 score greater than 10% had a significantly shorter PFS (mPFS = 8.81 versus 25.35 mo, p = 0.001) and OS (mOS 19.7 versus 44.5 mo, p = 0.002) than those with a Ki67 score less than or equal to 10. Receiver operating characteristic curve analysis for Ki67 revealed an area under the curve of 0.756 with a sensitivity of 90% and specificity of 71% for a cutoff of 10% for Ki67. Patients with loss of MTAP had a significantly shorter mPFS (9 versus 21.1 mo, p = 0.014) and mOS (19.7 versus 42.6 mo, p = 0.047) than those without MTAP loss.

Conclusions

In our study, Ki67 was prognostic for OS and PFS in patients with MPM treated with extended pleurectomy/decortication in a multimodality approach. Determination of Ki67 before surgery combined with specific clinical parameters could assist in clinical decision making by identifying patients, with high Ki67, who are unlikely to benefit from surgery.

Hyperthermic Intrathoracic Chemotherapy (HITOC) after Cytoreductive Surgery for Pleural Malignancies-A Retrospective, Multicentre Study

Simple Summary

There continues to be little research in the literature on perioperative outcomes after cytoreductive surgery (CRS) combined with intraoperative hyperthermic chemotherapy-lavage (HITOC) in patients with malignant pleural tumours. The aim of this multicentre study was to assess the results of the current practice in Germany so as to give recommendations to standardize the procedure. CRS with cisplatin-based HITOC can be performed with low major morbidity and a low rate of renal insufficiency, which was associated with the cisplatin dosage of irrigation.

Abstract

In the context of quality assurance, the objectives were to describe the surgical treatment and postoperative morbidity (particularly renal insufficiency). A retrospective, multicentre study of patients who underwent cytoreductive surgery (CRS) with cisplatin-based HITOC was performed. The study was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation (GZ: RI 2905/3-1)). Patients (n = 350) with malignant pleural mesothelioma (n = 261; 75%) and thymic tumours with pleural spread (n = 58; 17%) or pleural metastases (n = 31; 9%) were analyzed. CRS was accomplished by pleurectomy/decortication (P/D: n = 77; 22%), extended P/D (eP/D: n = 263; 75%) or extrapleural pneumonectomy (EPP: n = 10; 3%). Patients received cisplatin alone (n = 212; 61%) or cisplatin plus doxorubicin (n = 138; 39%). Low-dose cisplatin (≤125 mg/m² BSA) was given in 67% of patients (n = 234), and high-dose cisplatin (>125 mg/m² BSA) was given in 33% of patients (n = 116). Postoperative renal insufficiency appeared in 12% of the patients (n = 41), and 1.4% (n = 5) required temporary dialysis. Surgical revision was necessary in 51 patients (15%). In-hospital mortality was 3.7% (n = 13). Patients receiving high-dose cisplatin were 2.7 times more likely to suffer from renal insufficiency than patients receiving low-dose cisplatin (p = 0.006). The risk for postoperative renal failure is dependent on the intrathoracic cisplatin dosage but was within an acceptable range.

Hyperthermic Intrathoracic Chemotherapy for Malignant Pleural Mesothelioma: The Forefront of Surgery-Based Multimodality Treatment

Introduction: Malignant Pleural Mesothelioma (MPM) is characterized by an aggressive behavior and an inevitably fatal prognosis, whose treatment is still far from being standardized. The role of surgery is questionable since a radical resection is unattainable in most cases. Hyperthermic IntraTHOracic Chemotherapy (HITHOC) combines the advantages of antitumoral effects together with those of high temperature on the exposed tissues with the aim to improve surgical radicality. Material and Methods: this is a narrative review on the role of HITHOC in the management of MPM patients. To provide data on the beginnings and the historical evolution of this technique, we searched the available literature by selecting the more exhaustive papers on this topic. Results: from 1994 to date different authors experimented HITHOC following a cytoreductive surgery in MPM, obtaining in most cases a good local control and a better overall survival associated to very low complication rate. Conclusions: HITHOC may be considered as a safe, feasible and effective procedure although there is a high heterogeneity between different protocols adopted worldwide. More structured studies are needed to reach a unanimous consensus on this technique.

Malignant pleural mesothelioma: recent developments

PURPOSE OF REVIEW

Malignant pleural mesothelioma (MPM) is a rare, but aggressive tumor with still poor prognosis. In this article, we focus on recent developments in the management of MPM including diagnosis, staging, biomarkers, and treatment strategies.

RECENT FINDINGS

Molecular markers such as programmed death-ligand 1 (PDL-1), Breast Cancer gene 1-associated protein gene, and cyclin-dependent kinase inhibitor 2A (CDKN2A) have prognostic impact and should be considered for assessment in patient samples. In addition to histological subtype and tumor pattern, tumor volumetry plays an increasing important role in staging, assessment of treatment response, and prediction of survival. Several new blood-based biomarkers have been recently reported including peripheral blood DNA methylation, microRNAs, fibulin, and high-mobility group box 1, but have not been established in clinical routine use yet. Regarding treatment, targeted therapies, immunotherapy, and vaccination are considered as new promising strategies. Moreover, extended pleurectomy/decortication is favored over extrapleural pneumonectomy (EPP) and intensity-modulated radiotherapy represents a possible approach in combination with EPP and pleurectomy/decortication. Intracavitary treatment options are promising and deserve further investigations.

SUMMARY

Overall, there has not been a real breakthrough in the treatment of MPM. Further research and clinical trials are needed to evaluate outcome and to identify new potential treatment candidates.

Hyperthermic Intrathoracic Chemoperfusion for Malignant Pleural Mesothelioma: Systematic Review and Meta-Analysis

Simple Summary

Treatment of malignant mesothelioma with high-temperature chemotherapeutic instillation of the affected pleural space seems to be advantageous, but higher-quality studies are needed.

Abstract

Malignant pleural mesothelioma (MPM) is an aggressive malignancy of the pleural lining with exceptionally poor survival. Hyperthermic intrathoracic chemoperfusion (HITHOC) is commonly used with surgery in limited disease. However, data on its effect on survival are limited. In this systematic review and meta-analysis, we analyzed a total of 11 observational articles. HITHOC was compared to control arm that did not receive HITHOC in three studies including 762 patients. The pooled analysis of these studies revealed an SMD of 0.24, with 95% CI of 0.06–0.41 favoring the HITHOC group, reaching statistical significance. The survival effect of HITHOC in epithelioid MPM vs. non-epithelioid MPM was analyzed in four studies. Pooled analysis showed an SMD of 0.79 (95% CI = 0.48–1.10) favoring epithelioid MPM. Based on available data, there seems to be a benefit with HITHOC in regards to overall survival in the treatment of all mesothelioma patients. Multicenter randomized controlled trials are needed to validate and standardize this treatment approach.

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.

Debulking surgery for malignant tumors: the current status, evidence and future perspectives

Debulking surgery, also called cytoreductive surgery, is a resection of the tumor as much as possible and an intended incomplete resection for unresectable malignant tumors. Since the most important principle in surgical oncology is complete R0 resection, debulking surgery goes against the basic principle and obscures the concept of operability. However, debulking surgery has been advocated for various types of advanced malignant tumors, including gynecological cancers, urological cancers, gastrointestinal cancers, breast cancers and other malignancies, with or without adjuvant therapy. Positive data from randomized trials have been shown in subsets of ovarian cancer, renal cell carcinoma, colorectal cancer and breast cancer. However, recent trials for renal cell carcinoma, colorectal cancer and breast cancer have tended to show controversial results, mainly according to the survival improvement of nonsurgical systemic therapy alone. On the other hand, debulking surgery still has a therapeutic role for slow-growing and borderline malignant tumors, such as pseudomyxoma peritonei and thymomas. The recent understanding of tumor heterogeneity and clonal evolution responsible for malignancy and drug resistance indicates that select patients may obtain prolonged survival by the synergistic effect of debulking surgery and novel systemic therapy. This review aimed to describe the current status and evidence of debulking surgery in a cross-organ manner and to discuss future perspectives in the current era with advances in systemic therapy.

The Role of Neoadjuvant Chemotherapy in Patients With Resectable Malignant Pleural Mesothelioma-An Institutional and National Analysis

BACKGROUND

There is no standard of care with respect to the use of neoadjuvant chemotherapy (NAC) in resectable malignant pleural mesothelioma (MPM). We performed an intention-to-treat analysis with data from a single institution and the National Cancer Database (NCDB) to identify whether the use of NAC impacts survival in resectable MPM.

METHODS

Patients with MPM who had surgery with curative intent at Duke University from 1995 to 2017 were selected, and the 2004-2015 NCDB was used to identify MPM patients with clinical stage I-IIIB who underwent definitive surgery. For both cohorts, patients were stratified by receipt of NAC. Primary outcomes were overall survival and postresection survival (RS), which were estimated using Kaplan-Meier and multivariable Cox proportional hazards models.

RESULTS

A total of 257 patients met inclusion criteria in the Duke cohort. Compared with immediate resection (IR), NAC was associated with similar overall survival but an increased risk for postresection mortality in both unmatched (adjusted hazard ratio [HR] = 1.85, 95% confidence interval [CI] = 1.21 to 2.83) and propensity-matched (HR = 1.62, 95% CI = 1.03 to 2.55) cohorts. A total of 1949 NCDB patients were included: 1597 (81.9%) IR and 352 (18.1%) NAC. RS was worse for patients undergoing NAC in both unmatched (HR = 1.85, 95% CI = 1.21 to 2.83) and propensity-matched (HR = 1.29, 95% CI = 1.06 to 1.57) analyses compared with patients receiving IR.

CONCLUSIONS

In this intention-to-treat study, NAC was associated with worse RS compared with IR in patients with MPM. The risks and benefits of induction therapy should be weighed before offering it to patients with resectable MPM.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

SEOM clinical guidelines for the treatment of malignant pleural mesothelioma (2020)

Mesothelioma is a rare and aggressive tumour with dismal prognosis arising in the pleura and associated with asbestos exposure. Its incidence is on the rise worldwide. In selected patients with early-stage MPM, a maximal surgical cytoreduction in combination with additional antitumour treatment may be considered in selected patients assessed by a multidisciplinary tumor board. In patients with unresectable or advanced MPM, chemotherapy with platinum plus pemetrexed is the standard of care. Currently, no standard salvage therapy has been approved yet, but second-line chemotherapy with vinorelbine or gemcitabine is commonly used. Novel therapeutic approaches based on dual immunotherapy or chemotherapy plus immunotherapy demonstrated promising survival benefit and will probably be incorporated in the future.

Japanese Current Status of Curative-Intent Surgery for Malignant Pleural Mesothelioma

BACKGROUND

Few reports about surgical outcomes in malignant pleural mesothelioma (MPM) were based on reliable nationwide databases. Here we analyzed the incidence, surgical outcome, and operative risk factors using Japanese nationwide database.

METHODS

Characteristics and perioperative data from 622 patients who underwent curative-intent surgery for MPM between January 2014 and December 2017 were recorded from National Clinical Database of Japan. We analyzed the incidence, surgical outcomes, and risk factors for surgical complications after two surgical procedures (extrapleural pneumonectomy, EPP; and pleurectomy/decortication, P/D).

RESULTS

During 4 years, EPP was performed in 279 patients and P/D in 343. EPP was more frequently performed in less-MPM-experienced institutions, while P/D was more frequently performed in well-MPM-experienced institutions (P < .001), especially in high-volume centers with more than 10 cases during this period. P/D was more frequently performed, especially in high-volume centers. The morbidity rates were 45.2% in EPP and 35.9% in P/D. Heart failure and pneumonia were most frequent in EPP, while prolonged air leakage was most frequent in P/D. Thirty-day- and in-hospital mortality rates were 1.1% and 3.2% (EPP) and 1.2% and 3.2% (P/D), respectively. Regression analyses revealed that higher age (>65 years) was associated with operative complications in EPP (odds ratio, OR: 3.56 [1.26-8.56]), whereas no risk factor was observed in P/D.

CONCLUSIONS

In Japanese nationwide annual database, P/D was more frequently performed, especially in high-volume centers. Morbidity was higher in EPP than P/D; however, the mortality rates were quite low in Japan regardless surgical procedures.