Surgery in mesothelioma--where do we go after MARS?

Immunotherapy for advanced and recurrent malignant pleural mesothelioma

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects of immune checkpoint inhibitors (single-agent or combination therapy) in people with advanced malignant pleural mesothelioma in a first-line or salvage setting.

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.

Long-term outcomes after lung-sparing surgery for epithelial mesothelioma

Background

This observational study evaluates retrospectively the long-term outcomes after pleurectomy/decortication for pleural mesothelioma, with and without the resection/reconstruction of diaphragm and pericardium.

Methods

Data from 155 consecutive patients undergoing lung-sparing surgery for epithelial pleural mesothelioma were reviewed. Selection criteria for surgery were cT1-3, cN0-1, good performance status, age <80 years. Perioperative Pemetrexed-Platinum regimen was administered as induction in 101 cases (65.2%) and as adjuvant treatment in 54 cases (34.8%). Extended pleurectomy/decortication was performed in 87 cases (56.12%). In 68 patients (43.87%) standard pleurectomy/decortication was performed without resection/reconstruction of diaphragm and pericardium, when tumour infiltration was deemed absent after intraoperative frozen section. The log-rank test and Cox regression model were used to assess the factors affecting overall survival and recurrence free survival.

Results

Median follow-up was 20 months. The 2- and 5-year survival rate was 60.9% and 29.2% with a median survival of 34 months. An improved survival was observed when standard pleurectomy/decortication was carried out (P=0.007). A significant impact on survival was found comparing the TNM-stages (P=0.001), pT (P=0.002) and pN variables (P=0.001). Multivariate analysis identified the pN-status (P=0.003) and standard pleurectomy/decortication (P=0.017) as predictive for longer survival. The recurrence-free survival >12 months was strongly related to the overall survival (P<0.001). The macroscopic complete resection (P=0.001), TNM-stage (P=0.003) and pT-status (P=0.001) are related to relapse.

Conclusions

Within multimodal management of pleural mesothelioma, lung-sparing surgery is a valid option even with more conservative technique. A benefit for a longer survival was observed in the early stage of disease, with pN0 and when pleurectomy/decortication is carried out, preserving diaphragm and pericardium. Recurrence is not affected by the type of surgery, and a recurrence-free interval >12 months is predictive of an increased survival when the macroscopic complete resection is achieved.

Locoregional control and toxicity after pleurectomy/decortication and intensity-modulated pleural radiation therapy in patients with malignant pleural mesothelioma

Background

Treatment of malignant pleural mesothelioma (MPM) represents a major challenge for oncologists. Multimodality treatment, which generally involves induction chemotherapy, surgery and radiotherapy have recently shown promising results. The aim of this study was to evaluate the locoregional control and toxicity of intensity modulated radiotherapy (IMRT) after pleurectomy and decortication (P/D) as part of trimodality therapy for patients with locally advanced MPM.

Methods

We prospectively analyzed data from 20 patients with MPM treated at a single tertiary‐care institution. Initially every patient received induction chemotherapy with platinum‐based chemotherapy. After chemotherapy, patients without progression underwent P/D, and if feasible, hemi‐thoracic IMRT was administered at a planned dose of 50.4–54 Gy in 28–30 fractions and treated with 9–11 noncoplanar fields.

Results

A total of 15 of the 20 enrolled patients underwent P/D followed by IMRT to the hemi‐thoracic cavity. The median total radiotherapy dose was 48.7 Gy (23.4–54 Gy). Radiation pneumonitis (RP) developed in nine patients (60%), and of these, two patients (13.3%) experienced G3 or G4 RP. The estimated locoregional‐relapse‐free survival at two years was 75.9%, and the main pattern of recurrence was distant (72.7%). For the entire cohort median follow‐up was 22.7 months, median progression‐free survival was 18.9 months and median overall survival 23.6 months.

Conclusions

Platinum‐based chemotherapy followed by lung‐sparing surgery (P/D) and IMRT is a feasible and safe treatment modality that yields acceptable locoregional control in patients with locally advanced MPM; however, these results should be corroborated in larger studies.

Targeting Tie-2/angiopoietin axis in experimental mesothelioma confers differential responses and raises predictive implications

Malignant pleural mesothelioma is resistant to currently used treatment. Angiopoieitn-1 directly promotes mesothelioma cell growth in a Tie-2-dependent fashion. Angiopoietin/Tie-2 axis may thus be valid targets for therapeutic interventions against mesothelioma. We hypothesized that a soluble angiopoietin inhibitor (Murine Tek-deltaFc) would halt mesothelioma progression in vivo by enhancing mesothelioma cell proliferation and inhibiting tumor angiogenesis. Our hypothesis was challenged on two syngeneic mesothelioma in vivo models (AB1 cells-Balb/c mice and AE17 cells-C57BL/6 mice. Even though both mesothelioma cell lines express the Angiopoietin-1/-2 and Tie-2, murine Tek-deltaFc hampered AB1 but not AE17 mesothelioma growth in vivo by enhancing tumor cell apoptosis and limiting tumor angiogenesis. Neither angiopoietins (Angs)-1 and -2 nor the inhibitor affected mesothelioma cell growth in vitro. AB1 (responding) tumors were more vascularized and displayed higher endothelial Tie-2 and lower tumor Ang-1 expression than the (non-responding) AE17 tumors. Angiopoietins-1 and -2 are expressed in tumors and pleural cavity of mesothelioma patients demonstrating the clinical relevance of our experimental observations. In conclusion, disrupting Ang-Tie-2 signaling limits mesothelioma angiogenesis and halts tumor progression. Tumor vascularity, endothelial Tie-2 expression and tumor Ang-1 expression may predict mesothelioma response to Tek-deltaFc.

Radical multimodality therapy for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma is an almost always fatal tumour, for which palliative platinum-based chemotherapy is currently the standard treatment. Multimodal therapeutic strategies incorporating surgery, radiation therapy or photodynamic therapy and chemotherapy have been recommended for selected patients but there is no consensus about their effectiveness.

OBJECTIVES

To assess the benefits and harms of radical multimodal treatment options (including radical surgery ± radical radiotherapy ± photodynamic therapy ± systemic therapy) compared to each other or to palliative treatments, for people with malignant pleural mesothelioma.

SEARCH METHODS

We reviewed data from the Cochrane Lung Cancer group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase. We also checked reference lists of primary original studies, review articles and relevant conference proceedings manually for further related articles up to 21 March 2017.

SELECTION CRITERIA

We included parallel-group randomised controlled trials of multimodal therapy for people with malignant pleural mesothelioma (stages I, II or III) that measured at least one of the following endpoints: overall survival, health-related health-related quality of life, adverse events or progression-free survival. We considered studies regardless of language or publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted relevant information on participant characteristics, interventions, study outcomes, and data on the outcomes for this review, as well as information on the design and methodology of the studies. Two review authors assessed the risk of bias in the included trials using pre-defined 'Risk of bias' domains. We assessed the methodological quality using GRADE.

MAIN RESULTS

We conducted this review in accordance with the published Cochrane protocol. Two randomised clinical trials with 104 participants fulfilled our inclusion criteria. Both trials were at high risk of bias (for outcomes other than overall survival), and we rated the evidence as moderate quality for overall survival and low quality for all other outcomes. One trial compared combined extrapleural pneumonectomy (EPP) plus neoadjuvant platinum-based chemotherapy plus postoperative high-dose hemithoracic radiotherapy with combined EPP plus platinum-based chemotherapy. The other trial compared EPP plus postoperative hemithoracic radiotherapy with standard (non-radical) therapy alone following platinum-based chemotherapy (patients in the standard therapy arm received continued oncological management according to local policy, which could include further chemotherapy or palliative radiotherapy).For the first trial, median overall survival calculated from registration was 20.8 months (95% confidence interval (CI) 14.4 to 27.8) in the no-radiotherapy group and 19.3 months (95% CI 11.5 to 21.8) in the radiotherapy group. For the second trial, median overall survival was 14.4 months (95% CI 5.3 to 18.7) for patients allocated to EPP and 19.5 months (95% CI 13.4 to time not yet reached) for patients randomised to standard non-radical therapy. In the second trial, 12 serious adverse events were reported during the study period: ten in the EPP group and two in the non-radical therapy group. Overall health-related quality of life scores were not different between the two arms in either study. We could not perform a meta-analysis of the two included trials due to clinical heterogeneity. We also identified three ongoing trials evaluating the topic of our review.

AUTHORS' CONCLUSIONS

The overall strength of the evidence gathered in this review is low and there is a lack of available evidence to support the use of radical multimodality therapy in routine clinical practice (particularly as one trial suggests greater harm). Given the added cost of multimodality treatment and the possible increase in risk of adverse effects, the lack of evidence of their effectiveness probably means that these interventions should currently be limited to clinical trials alone.

The "don't eat me" signal CD47 is a novel diagnostic biomarker and potential therapeutic target for diffuse malignant mesothelioma

Diffuse malignant mesothelioma (DMM) is one of the prognostically most discouraging cancers with median survivals of only 12–22 months. Due to its insidious onset and delayed detection, DMM is often at an advanced stage at diagnosis and is considered incurable. Combined chemo- and radiotherapy followed by surgery only marginally affect outcome at the cost of significant morbidity. Because of the long time period between exposure to asbestos and disease onset, the incidence of DMM is still rising and predicted to peak around 2020. Novel markers for the reliable diagnosis of DMM in body cavity effusion specimens as well as more effective, targeted therapies are urgently needed. Here, we show that the “don't eat me” signalling molecule CD47, which inhibits phagocytosis by binding to signal regulatory protein α on macrophages, is overexpressed in DMM cells. A two-marker panel of high CD47 expression and BRCA1-associated protein 1 (BAP-1) deficiency had a sensitivity of 78% and specificity of 100% in discriminating DMM tumour cells from reactive mesothelial cells in effusions, which is superior to the currently used four-marker combination of BAP-1, glucose transporter type 1, epithelial membrane antigen and desmin. In addition, blocking CD47 inhibited growth and promoted phagocytosis of DMM cell lines by macrophages in vitro. Furthermore, DMM tumours in surgical specimens from patients as well as in a mouse DMM model expressed high levels of CD47 and were heavily infiltrated by macrophages. Our study demonstrates that CD47 is an accurate novel diagnostic DMM biomarker and that blocking CD47 may represent a promising therapeutic strategy for DMM.

Isolated thoracic perfusion with chemofiltration for progressive malignant pleural mesothelioma

Introduction

Therapy of malignant pleural mesothelioma and especially the adequate role of surgery in this context remain the subject of controversial discussions. Radical surgery in particular, which is associated with substantial morbidity, failed to translate into a definite survival advantage. We report on interim results of an ongoing Phase II study of regional chemotherapy in terms of isolated thoracic perfusion with chemofiltration (ITP-F).

Patients and methods

Twenty-eight patients (25 male, 3 female, mean age 63.4 years) with advanced pleural mesothelioma were included in this study. Isolation of the chest was achieved by insertion of a venous and arterial stop-flow balloon catheter via a femoral access. The aorta and inferior vena cava were blocked at the level of the diaphragm and the upper arms were blocked by pneumatic cuffs. Chemotherapy, consisting of 60 mg/m² cisplatin and 15 mg/m² mitoxantrone, was administered directly into the aorta. The isolated circuit was maintained for 15 minutes followed bŷ45 minutes of chemofiltration with a hemoprocessor until 5 L of filtrate were reached. The endpoints of the study were overall survival and quality of life (QoL).

Results

Out of 28 patients enrolled in the study, 5 had prior surgeries, 10 patients had systemic chemotherapy, and 5 patients additional irradiation. In all patients in restaging, clinical progress was noted. In all, 162 cycles were administered. Due to chemofiltration, toxicity was within tolerable limits, revealing World Health Organization grade I leucopenia and thrombocytopenia in 9 patients and mucositis grade I in 6 patients. The major surgical complication was inguinal lymphatic fistula in 40% of the cases. Gastrointestinal toxicity and/or neurotoxicity were never observed. One-year survival was 49%, 2-year and 3-year survival was 31%, and 5-year survival was 18%. Median overall survival was 12 months and progression-free survival 9 months.

Conclusion

ITP-F for patients with advanced pleural mesothelioma, progressive after standard therapies, is an effective and well-tolerated treatment modality, offering comparably long survival data at a good QoL.

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

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

Targeting the inhibitory receptor CTLA-4 on T cells increased abscopal effects in murine mesothelioma model

We previously demonstrated that blockade of immune suppressive CTLA-4 resulted in tumor growth delay when combined with chemotherapy in murine mesothelioma. Tumor-infiltrating T cells (TIT) after local radiotherapy (LRT) play critical roles in abscopal effect against cancer. We attempt to improve the local and abscopal effect by modulating T cell immunity with systemic blockade of CTLA-4 signal. The growth of primary tumors was significantly inhibited by LRT while CTLA-4 antibody enhanced the antitumor effect. Growth delay of the second tumors was achieved when the primary tumor was radiated. LRT resulted in more T cell infiltration into both tumors, including Treg and cytotoxic T cells. Interestingly, the proportion of Treg over effector T cells in both tumors was reversed after CTLA-4 blockade, while CD8 T cells were further activated. The expression of the immune-related genes was upregulated and cytokine production was significantly increased. LRT resulted in an increase of TIT, while CTLA-4 blockade led to significant reduction of Tregs and increase of cytotoxic T cells in both tumors. The abscopal effect is enhanced by targeting the immune checkpoints through modulation of T cell immune response in murine mesothelioma.

Surgical controversies in mesothelioma: MesoVATS addresses the role of surgical debulking

Contemporary multi-modality treatment of malignant mesothelioma remains challenging. The merits of surgical resection and the particular extent of resection continue to be debated topics. To date few randomized surgical trials have been completed to address many lingering issues concerning surgery in mesothelioma. Recently, the MesoVATS trial shows us that a minimally invasive thoracoscopic procedure for curative resection in mesothelioma is of limited benefit. Results of ongoing clinical trials are awaited.

New directions in mesothelioma treatment

For most patients with mesothelioma, symptom control and palliative chemotherapy are mainstays of care. First-line cisplatin/pemetrexed chemotherapy has demonstrated survival and quality-of-life benefits. A randomized controlled trial adding bevacizumab to cisplatin and pemetrexed recently reported improved survival and time to progression, and may constitute a new standard of care where economically viable. Immunotherapy is under active investigation and positive results have been reported from single-arm studies of the anti-CTLA4 antibody tremelimumab; the anti-PD-1 antibody pembrolizumab; and mesothelin-targeting strategies. Symptom control remains critical for patient well-being, and includes management of pleural effusion, analgesia, treatment of symptomatic masses and management of systemic symptoms. There is increasing evidence that tunneled pleural catheters are preferred over talc pleurodesis for recurrent pleural effusion.

Adoption of pleurectomy and decortication for malignant mesothelioma leads to similar survival as extrapleural pneumonectomy

OBJECTIVE

We changed our surgical approach to malignant pleural mesothelioma (MPM) in August 2011 and adopted pleurectomy and decortication (PD) instead of extrapleural pneumonectomy (EPP). In this study, we analyzed our perioperative and survival results during the 2 periods.

METHODS

All patients who underwent surgical intervention for MPM during 2003-2014 were included. Data were retrospectively analyzed from a prospective database. Before August 2011, patients underwent evaluation for EPP and adjuvant chemoradiation (group 1). After August 2011, patients were evaluated for PD and adjuvant chemotherapy and/or radiation (group 2). Demographic characteristics, surgical technique, histology, side, completeness of resection, and types of treatments were recorded. Statistics was performed using Student t test, χ(2) tests, uni- and multivariate regression, and Kaplan-Meier survival analysis.

RESULTS

The same surgical team operated on 130 patients. Median age was 55.7 years (range, 26-80 years) and 76 were men. EPP and extended PD was performed in 72 patients. Ninety-day mortality was 10%. Median survival was 17.8 months with a 5-year survival rate of 14%. Uni- and multivariate analyses showed that epithelioid histology, stage N0, and trimodality treatment were associated with better survival (P = .039, P = .012, and P < .001, respectively). Demographic variables and overall survival (15.6 vs 19.6 months, respectively) were similar between the groups, whereas nonepithelioid histology, use of preoperative chemotherapy, and incomplete resections were more frequent in group 2 (P < .001, P < .001, and P = .006, respectively). Follow-up was shorter in group 2 (22.5 ± 20.6 vs 16.4 ± 10.9 months; P < .001).

CONCLUSIONS

Adoption of PD as the main surgical approach is not associated with survival disadvantage in the surgical treatment of MPM.

Extrapleural pneumonectomy plus rib resection for malignant pleural mesothelioma: a case report

We report a case of a 58-year-old Japanese man with epithelioid-type MPM, with a left chest wall protruding tumor, who underwent extrapleural pneumonectomy and chest wall resection. Postsurgical pathology showed that surgical margins were free of mesothelioma cells. Positron emission tomography taken 5 years after surgery showed no recurrence at any site, suggesting that long-term survival could be dependent on margin-free tumor resection or that specific MPM subgroups have lower malignant potential, leading to improved survival.

Current issues in malignant pleural mesothelioma evaluation and management

Malignant pleural mesothelioma (MPM) is an uncommon disease most often associated with occupational asbestos exposure and is steadily increasing in worldwide incidence. Patients typically present at an older age, with advanced clinical stage and other medical comorbidities, making management quite challenging. Despite great efforts, the prognosis of MPM remains poor, especially at progression after initial treatment. Macroscopic complete resection of MPM can be achieved through extrapleural pneumonectomy (EPP) or extended (ie, radical) pleurectomy (e-P/D) in selected patients and can result in prolonged survival when incorporated into a multimodality approach. Given the morbidity associated with surgical resection of MPM, optimizing identification of appropriate patients is essential. Unfortunately, most patients are not candidates for EPP or e-P/D due to advanced stage, age, and/or medical comorbidity. Pemetrexed and platinum combination chemotherapy has become the cornerstone of therapy for patients with unresectable disease because the combination is associated with improved survival and quality of life in treated patients. However, MPM eventually becomes resistant to initial therapy, and benefit to further lines of therapy has not been substantiated in randomized clinical trials. Translational research has provided exciting insights into tumorigenesis, biomarkers, and immune response in MPM, leading to the development of multiple novel therapeutic agents that are currently in clinical trials. These advances hold the promise of a new era in the treatment of MPM and suggest that this disease will not be left behind in the war on cancer.

Malignant pleural mesothelioma: current and future perspectives

Mesothelioma still remains an occupational related cancer with severe outcome. It is usually diagnosed at advanced stage since it does not demonstrate early symptoms. Several efforts have been made towards removing all materials inducing mesothelioma in the work setting and new work protection measures have been applied. Although we have new targeted treatments and radical surgery as arrows in the quiver, the type of mesothelioma and early diagnosis still remain the best treatment approach. Novel treatment modalities have been explored and several others are already on the way. In the current review we will present current data for mesothelioma and future perspectives.

Malignant pleural mesothelioma and the Society of Thoracic Surgeons Database: an analysis of surgical morbidity and mortality

BACKGROUND

To date, reported surgical morbidity and mortality for pleurectomy/decortication and extrapleural pneumonectomy performed for malignant pleural mesothelioma primarily represent the experience of a few specialized centers. For comparison, we examined early outcomes of pleurectomy/decortication and extrapleural pneumonectomy from a broader group of centers/surgeons participating in the Society of Thoracic Surgeons-General Thoracic Database.

METHODS

All patients in the Society of Thoracic Surgeons-General Thoracic Database (version 2.081, representing 2009-2011) who underwent pleurectomy/decortication or extrapleural pneumonectomy for malignant pleural mesothelioma were identified. Patient characteristics, morbidity, mortality, center volume, and procedure were examined using univariable and multivariable analyses.

RESULTS

A total of 225 patients underwent pleurectomy/decortication (n = 130) or extrapleural pneumonectomy (n = 95) for malignant pleural mesothelioma at 48 centers. Higher volumes of procedures (≥5/y) were performed at 3 pleurectomy/decortication and 2 extrapleural pneumonectomy centers. Patient characteristics were statistically equivalent between pleurectomy/decortication and extrapleural pneumonectomy groups, except those undergoing extrapleural pneumonectomy were younger (63.2 ± 7.8 years vs 68.3 ± 9.5 years; P < .001) and more likely to have received preoperative chemotherapy (30.1% vs 17.8%; P = .036). Major morbidity was greater after extrapleural pneumonectomy, including acute respiratory distress syndrome (8.4% vs 0.8%; P = .005), reintubation (14.7% vs 2.3%; P = .001), unexpected reoperation (9.5% vs 1.5%; P = .01), and sepsis (4.2% vs 0%; P = .03), as was mortality (10.5% vs 3.1%; P = .03). Multivariate analyses revealed that extrapleural pneumonectomy was an independent predictor of major morbidity or mortality (odds ratio, 6.51; P = .001). Compared with high-volume centers, increased acute respiratory distress syndrome was seen in low-volume centers performing extrapleural pneumonectomy (0% vs 12.5%; P = .05).

CONCLUSIONS

Extrapleural pneumonectomy is associated with greater morbidity and mortality compared with pleurectomy/decortication when performed by participating surgeons of the Society of Thoracic Surgeons-General Thoracic Database. Effects of center volume require further study.

Radical pleurectomy/decortication followed by high dose of radiation therapy for malignant pleural mesothelioma. Final results with long-term follow-up

PURPOSE

We have previously shown the feasibility of delivering high doses of radiotherapy in malignant pleural mesothelioma (MPM) patients who underwent radical pleurectomy/decortication (P/D) or surgical biopsy. In this report, we present the long-term results of MPM patients treated with radical P/D followed by high doses of radiotherapy.

METHODS AND MATERIALS

Twenty consecutive MPM patients were enrolled in this prospective study and underwent radical P/D followed by high dose radiotherapy. The clinical target volume was defined as the entire hemithorax excluding the intact lung. The dose prescribed was 50 Gy in 25 fractions. Any FDG-avid areas or regions of particular concern for residual disease were given a simultaneous boost to 60 Gy. Nineteen patients received cisplatin/pemetrexed chemotherapy. Kaplan-Meier analysis was used to calculate rates of overall survival (OS), progression-free survival (PFS), and loco-regional control (LRC).

RESULTS

The median follow-up was of 27 months. The median OS and PFS were 33 and 29 months, respectively. The median LRC was not reached. The Kaplan-Meier estimates of OS at 2 and 3 years were 70% and 49%, respectively. The estimates of PFS at 2 and 3 years were 65% and 46%, respectively. The estimates of LRC at 2 and 3 years were 68% and 59%, respectively. The predominant pattern of failure was distant: 7 patients developed distant metastases as the first site of relapse, whereas only 3 patients experienced an isolated loco-regional recurrence. No fatal toxicity was reported. Five Grades 2-3 pneumonitis were documented.

CONCLUSIONS

High dose radiation therapy following radical P/D led to excellent loco-regional control and survival results in MPM patients. A median OS of 33 months and a 3-year OS rate of 49% are among the best observed in recent studies, supporting the idea that this approach represents a concrete therapeutic option for malignant pleural mesothelioma.

Which type of surgery should become the preferred procedure for malignant pleural mesothelioma: extrapleural pneumonectomy or extended pleurectomy?

PURPOSES

Since radiation and chemotherapy have limitations as therapies for malignant pleural mesothelioma (MPM). The type of surgery [extrapleural pneumonectomy (EPP), extended pleurectomy (E/P), and pleurectomy/decortication (P/D)] remains controversial.

METHODS

This study involves 76 consecutive patients. 58 of the cases were males (76%) with a median age of 53.17±10.93 years. EPP, E/P, and P/D were performed in 31, 20, and 25 cases, respectively.

RESULTS

The median survival time was 20 months in all patients. Overall, five-year survival rate was 14.3%. The survival rate was significantly better in epithelioid mesothelioma (P=0.049). For EPP cases, the median survival rate was 17 months, and the three-to-five year survival rates were 21% and 17%, respectively. For E/P cases, the median survival rate was 27 months and the three-year and four-year survival rates were 34% and 30%, respectively. For P/D cases, the median survival rate was 15 months and the three-to-five year survival rate was 13% and 0%. There were no statistically significant differences between the three surgical techniques (P=0.088). A comparative analysis indicates only a statistically significant difference in the E/P and P/D comparison (P=0.032). Hospital mortality showed a higher trend in EPP group (EPP: 12.9%, E/P: 0% and P/D: 4%, P=0.145). N2 cases, there were no cases of two-year survival. The survival rate in N2 was comparatively much lower, which was statistically significant (P=0.005). In multivariate analysis, only P/D (OR 0.3, 95% CI: 0.1-0.9, P=0.049) and N2 (OR 1.6, 95% CI: 0.9-2.6, P=0.090) were found to be poor prognostic factors.

CONCLUSIONS

E/P could be encouraged to EPP with lower mortality rate and better survival trend in MPM. N2 diseases were negative prognostic factors in MPM.

Surgery in the treatment of malignant pleural mesothelioma: recruitment into trials should be the default position

BACKGROUND

Europe is at the peak of an epidemic of malignant pleural mesothelioma and the burden of disease is likely to continue rising in the large areas of the world where asbestos remains unregulated. Patients with mesothelioma present with thoracic symptoms and radiological changes so respiratory physicians take a leading role in diagnosis and management. Belief that the modest survival times reported after radical surgery, whether alone or as part of multimodal therapy, are longer than they it would have been without surgery relies on data from highly selected, uncontrolled, retrospectively analysed case series. The only randomised study, the Mesothelioma and Radical Surgery (MARS) trial showed no benefit. A simple modelling study of registry patients, described here, shows that an impression of longer survival is eroded when patients who were never candidates for operation on grounds of histology, performance status and age are sequentially excluded from the model.

CONCLUSION

Whenever the question arises `Might an operation help me?' there are two responses that can and should be given. The first is that there is doubt about whether there is any survival or symptomatic benefit from surgery but we know that there is harm. The second is that there are on-going studies, including two randomised trials, which patients should be informed about. The authors suggest that the default position for clinicians should be to encourage recruitment into these trials.