Trimodality therapy for malignant pleural mesothelioma

Impact of Neoadjuvant and Adjuvant Pleural Intensity-Modulated Radiotherapy in Multimodality Treatment for Malignant Pleural Mesothelioma

BACKGROUND

Few malignancies provoke as many controversies about treatment as pleural mesothelioma. There is limited experience with novel radiotherapy techniques worldwide in adjuvant and particularly in neoadjuvant settings within multimodality treatment. The objective of the current study was to investigate the long-term outcome of neoadjuvant and adjuvant pleural intensity-modulated radiotherapy (IMRT) combined with macroscopic complete resection with or without chemotherapy.

METHODS

We retrospectively analyzed a consecutive cohort of 59 patients who were diagnosed with pleural mesothelioma and underwent multimodality treatment including macroscopic complete resection and neoadjuvant or adjuvant IMRT between 2005 and 2019 at the Department of Thoracic Surgery, Medical University of Vienna, Austria.

RESULTS

In total, 59 patients (median age 59 years; IQR 54-66, male, n = 48; 81%) were included. Forty-seven patients underwent trimodality treatment consisting of induction chemotherapy, extrapleural pneumonectomy, and adjuvant IMRT. Novel neoadjuvant IMRT with (n = 9) or without (n = 3) chemotherapy followed by extrapleural pneumonectomy was performed in 12 patients. Median overall survival (OS) of all patients was 23.2 months (95% CI; 18.1-28.2) and 3- and 5-year survival rates were 33% and 28%, respectively. Survival was comparable between therapies including neoadjuvant versus adjuvant IMRT (median OS 17.5 vs. 24.0 months, p = 0.39).

CONCLUSIONS

Neoadjuvant pleural IMRT has been investigated as a novel treatment option for highly selected cases in pleural mesothelioma. Neoadjuvant IMRT was effective and safe in patients treated in a high-volume institution but showed no relevant survival benefit compared to adjuvant IMRT within multimodality treatment.

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

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

A Trimodality, Four-Step Treatment including Chemotherapy, Pleurectomy/Decortication and Radiotherapy in Early-Stage Malignant Pleural Mesothelioma: A Single-Institution Retrospective Case Series Study

Simple Summary

Multimodality treatment can improve outcome of malignant pleural mesothelioma (MPM) patients. However, the ideal scheme of combination of them is still unknown. We analyzed a case series of 17 patients treated at our institution with a sequence of induction chemotherapy, surgery, adjuvant radiotherapy and chemotherapy. Median overall survival was 32.1 months, median progression free survival was 23.7 months with a safe profile. These data according to our experience represent a great example of feasibility in clinical practice of three-modality four step approach and encourage further prospective studies to better define the details of treatment.

Abstract

Background: Multimodality treatment is considered the best treatment strategy for malignant pleural mesothelioma (MPM). However, the ideal combination of them is still a matter of controversy. Here, we report a case series of MPM treated with a trimodality approach: induction chemotherapy (CT), pleurectomy/decortication (P/D), postoperative radiotherapy (RT) and post-operative CT. Methods: A retrospective case series of 17 MPM patients treated between 2013 and 2020 is presented. Patients had epithelial or mixed MPM diagnosed by video-assisted thoracoscopy and pathologic IMIG stage I or II disease. Treatment details and radiological data were collected. Induction therapy consisted of combination of cisplatin and pemetrexed, every 21 days for two cycles. P/D was performed 4–6 weeks after induction CT, post-operative RT 3–6 weeks after surgery, while post-operative CT was given 4–6 weeks after RT, with the same schedule of induction. Results: All patients showed objective response or stability of disease at the restaging following induction CT and underwent surgery by posterolateral thoracotomy. There were two cases of cardiac arrest as major intraoperative complication, both resolved by manual cardiac massage. Minor complications included one hemidiaphragm elevation, 1 anemia requiring blood transfusion, one wound infection, and two persistent air leaks. Median overall survival was 32.1 months, median progression free survival was 23.7 months. Conclusions: These results suggest the feasibility of these trimodality treatment scheme for early stage MPM patients. Larger series and long-term prospective studies are needed to confirm the validity of this strategy.

GOECP/SEOR clinical guidelines on radiotherapy for malignant pleural mesothelioma

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

Does size matter? -a population-based analysis of malignant pleural mesothelioma

Background

The 8^th edition staging system for malignant pleural mesothelioma (MPM) has been proposed. The size of tumor is not taken into consideration. We intend to elucidate the prognostic value of the size of MPM and evaluate the current staging system via the data of SEER database.

Methods

All cases of primary MPM were identified and extracted from the SEER database during the period of 2004–2016. The endpoints were overall survival (OS) and cancer-specific survival (CSS) which were analyzed using Kaplan-Meier method. Log-rank test and Cox regression were utilized to identify the prognostic factors.

Results

A total of 2,138 patients were included in the primary cohort. The 1-, 3- and 5-year survival rates of MPM were 39.4%, 11.8% and 3.8%. Older, male and advanced stage patients accounted for larger proportion of the cohort. Besides tumor extension, lymph node involvement and metastatic status, tumor size, pathological type and differentiation grade were significant prognostic factors. In the stratified analysis of tumor extension, size is a significant prognostic factor in T2 patients and indicates inferior survival outcomes. Surgery, chemotherapy and radiation can increase both OS and CSS in MPM patients. Triple combination treatments showed a superiority to other treatments.

Conclusions

Tumor size matters in the prognosis of MPM especially in the early stage of MPM patients. The adjusted TNM staging system incorporating tumor size has better accuracy than the 8^th edition IMIG system. However, some stages had not been fully identified. More cases of early stages are warranted for essential revision.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Extra-pleural pneumonectomy

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

The Role of Adjuvant Radiotherapy in the Treatment of Pleural Mesothelioma

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Combined modality treatment in mesothelioma: a systemic literature review with treatment recommendations

In spite of recent progress, malignant pleural mesothelioma (MPM) remains synonymous with poor prognosis. A selected minority (<10%) of patients is eligible for a radical treatment with a combination of systemic chemotherapy (CT) and/or surgery and/or radiotherapy (RT), in an effort to maintain locoregional tumor control after achieving a macroscopically complete resection (MCR). However, as of yet there is no standard of care for this so-called multimodality treatment. As its potential gain is still limited (approximately one year added to overall survival), we must balance its efficacy with its cumulative toxicity. Several combined modality treatment trials are currently ongoing using novel techniques in surgery, RT and/or CT in an attempt to reduce the morbidity and mortality associated with older multimodality treatment protocols. Guidelines are following suit and are now including or mentioning this treatment option. In this systematic review, we analyze the available data in order to address the following questions: Is combined modality better than single modality? What is the optimal regimen within each modality? What is the optimal sequence of combined modality?

Radiotherapy for the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is an aggressive disease that continues to be associated with poor outcomes. Although, traditionally this disease is considered to be resistant to radiotherapy, more recent evidence suggests that radiotherapy can produce positive outcomes. Over the past 15 years, the development of new, highly conformal radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), has enabled investigators to optimise the delivery of high-dose radiotherapy to the whole of the hemithorax. Prospective single-arm trials have shown that the median survival of patients who have completed high-dose hemithoracic radiotherapy after extrapleural pneumonectomy could reach 23·9-39·4 months independent of the chemotherapeutic response, suggesting that IMRT could potentially have an intrinsic benefit to this subset of patients. These observations have led to a change in practice, with the introduction of adjuvant pleural IMRT after pleurectomy-decortication and the development of induction-accelerated hemithoracic IMRT followed by extrapleural pneumonectomy. This Review focuses on recent observations on the role of radiotherapy in the treatment of malignant pleural mesothelioma, with particular emphasis on the results of clinical trials that evaluate the role of high-dose hemithoracic radiotherapy.

The role of radical radiotherapy in the management of malignant pleural mesothelioma: A systematic review

Malignant pleural mesothelioma (MPM) is a devastating disease with limited treatment options and a dismal prognosis. Attempts to employ radical radiotherapy in this disease have been limited by the complex shape of the pleura and the dose restrictions necessitated by the close proximity of radiosensitive structures. Recent shifts towards a 'lung sparing' surgical approach in MPM have further heightened these challenges. The aim of this systematic review is to assess recent advances in radiotherapy planning and delivery, to ascertain how these developments have impacted on the feasibility of delivering photon-based, high-dose radiotherapy with radical intent in MPM. Three electronic databases were searched and a total of 249 articles reviewed. The challenge of generating high quality, practice-defining data for diseases such as MPM was highlighted by the identification of just two randomised studies. Much of the literature consisted of low quality, retrospective data with small cohorts and inconsistent reporting on radiotherapy techniques and dosimetry. Nevertheless, a number of prospective phase II studies were identified to suggest that radical doses of radiotherapy can be delivered safely after a lung sparing procedure in MPM, reporting encouraging survival data and acceptable levels of toxicity.

Induction chemotherapy vs post-operative adjuvant therapy for malignant pleural mesothelioma

INTRODUCTION

Malignant pleural mesothelioma (MPM) is an aggressive neoplasia. Multidisciplinary treatments, including the association of induction and/or adjuvant therapeutic regimens with surgery, have been reported to give encouraging results. Current therapeutic options are not well standardized yet, especially regarding the best association between surgery and medical treatments. The present review aims to assess safety, efficacy and outcomes of different therapies for MPM. Areas covered: This article focuses on the multimodality treatment of mesothelioma. A systematic review was performed by using electronic databases to identify studies that considered induction and adjuvant approaches in MPM therapy in a multidisciplinary setting, including surgery. Endpoints included overall survival, disease free survival, disease recurrence, and complications. Expert commentary: This systematic review offers a comprehensive view of current multidisciplinary therapeutic strategies for MPM, suggesting that multimodality therapy offers acceptable outcomes with better results reported for trimodality approaches. Individualization of care for each patient is fundamental in choosing the most appropriate treatment. The growing complexity of treatment protocols mandates that MPM patients be referred to specialized Centers, in which every component of the interdisciplinary team can provide the necessary expertise and quality of care.

Intraoperative near-infrared imaging of mesothelioma

Though difficult to achieve, complete resection of malignant pleural mesothelioma is paramount to improving patient survival. Surgeons have traditionally been limited to using visual inspection and manual palpation to locate and remove cancerous tissue. However, intraoperative molecular imaging (IMI) is a promising new technology in surgery. Molecular imaging utilizes a fluorescent tracer that selectively accumulates in cancer cells. An imaging device is then used to detect and augment the fluorescent signal emitted from the fluorescent cancer cells. Our group and others have demonstrated that molecular imaging with either indocyanine green (ICG) or a folate receptor alpha (FRα) targeted fluorophore can accurately identify a number of intrathoracic malignancies. Early studies of intraoperative imaging have suggested its efficacy for malignant pleural mesothelioma. In a murine model of mesothelioma, intraoperative imaging was found to have sensitivity of 87% and specificity of 83%. In a pilot human study, eight patients with biopsy-proven epithelial malignant pleural mesothelioma were administered 5 mg/kg of intravenous ICG injection 24 h prior to resection. The following day, a near-infrared (NIR) imaging device was used to detect tumor fluorescence intraoperatively. After what was believed to be complete tumor excision, the wound bed was re-imaged for residual fluorescence indicative of retained tumor. When residual fluorescence was detected, additional tissue was resected, if feasible, and specimens were sent for pathologic correlation. In all cases, intraoperative fluorescence localized to mesothelioma deposits which were confirmed on final pathology. Following resection, fluorescence was confirmed ex vivo with a mean tumor-to-background ratio (TBR) of 3.2 (IQR: 2.9-3.4). It is hoped that this technology will improve outcomes for mesothelioma patients by allowing for a more complete oncologic resection.

The IASLC Mesothelioma Staging Project: Proposals for Revisions of the N Descriptors in the Forthcoming Eighth Edition of the TNM Classification for Pleural Mesothelioma

INTRODUCTION

Nodal categories for malignant pleural mesothelioma are derived from the lung cancer staging system and have not been adequately validated. The International Association for the Study of Lung Cancer developed a multinational database to generate evidence-based recommendations to inform the eighth edition of the TNM classification of malignant pleural mesothelioma.

METHODS

Data from 29 centers were entered prospectively (n = 1566) or by transfer of retrospective data (n = 1953). Survival according to the seventh edition N categories was evaluated using Kaplan-Meier survival curves and Cox proportional hazards regression analysis. Survival was measured from the date of diagnosis.

RESULTS

There were 2432 analyzable cases: 1603 had clinical (c) staging, 1614 had pathologic (p) staging, and 785 had both. For clinically staged tumors there was no separation in Kaplan-Meier curves between cN0, cN1 or cN2 (cN1 versus cN0 hazard ratio [HR] = 1.06, p = 0.77 and cN2 versus cN1 HR = 1.04, p = 0.85). For pathologically staged tumors, patients with pN1 or pN2 tumors had worse survival than those with pN0 tumors (HR = 1.51, p < 0.0001) but no survival difference was noted between those with pN1 and pN2 tumors (HR = 0.99, p = 0.99). Patients with both pN1 and pN2 nodal involvement had poorer survival than those with pN2 tumors only (HR = 1.60, p = 0.007) or pN0 tumors (HR = 1.62, p < 0.0001).

CONCLUSIONS

A recommendation to collapse both clinical and pN1 and pN2 categories into a single N category comprising ipsilateral, intrathoracic nodal metastases (N1) will be made for the eighth edition staging system. Nodes previously categorized as N3 will be reclassified as N2.

How does the timing of chemotherapy affect outcome following radical surgery for malignant pleural mesothelioma?

OBJECTIVES

There is little evidence regarding the use of chemotherapy as part of multimodality treatment of malignant pleural mesothelioma (MPM). We aimed to determine whether, in those patients fit for chemotherapy, a delay in this treatment affected survival.

MATERIALS AND METHODS

We analysed postoperative variables of 229 patients undergoing either extrapleural pneumonectomy (EPP) (81 patients) or extended pleurectomy-decortication (EPD) (197 patients) for MPM at a single centre. There was no standard protocol for additional chemotherapy and varied with referral centre. Outcome was compared between 4 chemotherapy strategies: true adjuvant therapy, neo-adjuvant therapy, therapy reserved until evidence of disease progression in those otherwise fit in the post-operative setting, and those unfit for chemotherapy.

RESULTS

There was no effect of the timing of chemotherapy on overall or progression free survival in patients fit enough for treatment (p=0.39 and p=0.33 respectively). However delaying chemotherapy until evidence of disease progression in patients with non-epithelioid disease had a detrimental effect on overall survival (OS), and on progression free survival (PFS) in lymph node positive patients (15.6 vs. 8.2 months p=0.001, and 14.9 vs. 6.0 months p=0.016). Further analysis of 169 patients receiving platinum/pemetrexed as first line treatment, showed similar results; there was no effect of the timing of chemotherapy on OS or PFS (p=0.80 and p=0.53 respectively) and an improved OS in patients with non-epithelioid disease, and improved PFS in those with lymph node metastases, if chemotherapy was given in the immediate adjuvant setting (p=0.001 and 0.038) when therapy was not delayed until disease progression.

CONCLUSION

Our results suggest that the timing of additional chemotherapy may be important in those with a poorer prognosis on the basis of cell type and nodal stage. In these patients additional postoperative chemotherapy should not be delayed.

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.

Induction Therapy for Mesothelioma

One particular approach of multimodality treatment for mesothelioma is induction therapy followed by surgery. Among its several advantages, the most important is downstaging of the tumor into a resectable stage, although morbidity and mortality might be increased. In this article we review the principles and outcome of different modalities for induction treatment of mesothelioma.

Current surgical strategies for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is associated with a poor prognosis. The main components of multimodality treatment include surgery, chemotherapy, and radiation therapy. Surgery remains controversial. Two procedures are currently offered: extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D). The recent scientific literature suggests that P/D is a well-tolerated procedure, with the potential of becoming a default procedure in multimodality regimens. However, the precise treatment schemes and surgical procedures are yet to be established. In our study, we review the advantages and disadvantages of EPP and P/D, summarize the post-EPP and post-P/D observations (including mortality, morbidity, and median survival time), and discuss the choice of surgical technique (EPP vs. P/D). Moreover, we highlight the aspects of the multimodality treatments that are offered to MPM patients, including chemotherapy, radiotherapy, intensity-modulated radiation therapy, and other types of therapy.

Accelerated hemithoracic radiation followed by extrapleural pneumonectomy for malignant pleural mesothelioma

OBJECTIVE

To evaluate a new protocol of accelerated hemithoracic intensity-modulated radiation therapy (IMRT) followed by extrapleural pneumonectomy (EPP) for patients with resectable malignant pleural mesothelioma (MPM).

METHODS

A total of 25 Gy of radiation was delivered in 5 daily fractions over 1 week to the entire ipsilateral hemithorax with concomitant boost of 5 Gy to volumes at high risk based on computed tomography and positron emission tomography scan findings. EPP was performed at 6 ± 2 days after the end of radiation therapy. Adjuvant chemotherapy was offered to patients with ypN2 disease.

RESULTS

A total of 62 patients were included between November 2008 and October 2014. One patient died in the hospital 2 months after EPP, for an operative mortality of 1.6%, and 2 died after discharged from the hospital for an overall treatment-related mortality (grade 5 toxicity) of 4.8%. Twenty-four patients (39%) developed grade 3 to 5 (grade 3+) complications. On final pathology, 94% of the patients were stage III or IV, and 52% had ypN2 disease. The median survival for all patients as an intention-to-treat analysis was 36 months. The median overall survival and disease-free survival was 51 and 47 months, respectively, in epithelial subtypes, compared with 10 and 8 months in biphasic subtypes (P = .001). Ipsilateral chest recurrence occurred in 8 patients.

CONCLUSIONS

Accelerated hemithoracic IMRT followed by EPP has become our preferred approach for resectable MPM. The results have been encouraging in patients with epithelial subtype.

Interim results of pleurectomy/decortication and intraoperative intrapleural hyperthermic cisplatin perfusion for patients with malignant pleural mesothelioma intolerable to extrapleural pneumonectomy

OBJECTIVE

Surgical procedure for malignant pleural mesothelioma (MPM) remains controversial. We reviewed our protocol including pleurectomy/decortication (P/D) for patients with malignant pleural mesothelioma who were intolerable to extrapleural pneumonectomy (EPP).

PATIENTS AND METHODS

From June 2010 to April 2014, 14 patients with MPM were intended to treat with multimodality therapy including surgery. Four patients who were intolerable to EPP received a protocol consisting of P/D and intraoperative intrapleural hyperthermic cisplatin perfusion, followed by systemic chemotherapy. Ten patients received trimodality treatment of EPP, systemic chemotherapy, and intensity modulated radiation therapy for hemithorax. Surgical outcomes of acute operative results and interim survivals were examined and compared between the groups.

RESULTS

All patients obtained macroscopic complete resection and received multimodality treatment in P/D and EPP groups. Operation time was longer in P/D group; however, there were no differences in ICU stays or hospitalizations. Four patients in P/D group and seven patients in EPP group experienced postoperative complications; however, there was no operative morality. EPP group suffered from cardiac complications and P/D group had prolonged airleak. Full walk recovery was obtained earlier in P/D group. One patient in P/D group had a local recurrence 11 months after surgery, while the other three patients survived 23-41 months with no evidence of diseases.

CONCLUSIONS

P/D and intraoperative intrapleural cisplatin perfusion achieved a favorable macroscopic resection in patients with MPM who were intolerable to EPP. Postoperative complications were manageable and survival could be promising. Further study warrants with a larger number of patients.

Clinical experience of volumetric modulated arc therapy for malignant pleural mesothelioma after extrapleural pneumonectomy

The purpose of this study was to evaluate the efficacy and safety of volumetric modulated arc therapy (VMAT) after extrapleural pneumonectomy (EPP) in patients with malignant pleural mesothelioma (MPM). A total of 15 patients who received VMAT after EPP were enrolled. All patients were males, and the median age was 67 years (Stage IB in two, II in six, and III in seven patients). The clinical target volume (CTV) included the entire preoperative ipsilateral hemithorax and involved nodal stations. The CTV was generally expanded by 10-15 mm beyond the planning target volume (PTV). The dose prescription was designed to cover 95% of the PTV with 54 Gy in 30 fractions. The median follow-up period was 11 months. Treatment-related toxicities were evaluated by Common Terminology Criteria for Adverse Events (CTCAE) ver. 4. One-year local control, disease-free survival, and overall survival rates were 55.7% [95% confidence interval (CI): 25.6-85.8%], 29.3% (95% CI: 5.3-53.3%), and 43.1% (95% CI: 17.1-69.0%), respectively. According to the histological analysis, the one-year LC rate was significantly worse in patients with non-epithelial type (biphasic and sarcomatoid types) than in patients with epithelial type [epithelial type: 83.3% (95% CI, 53.5-100%), non-epithelial type: 0% (95% CI, 0%), P = 0.0011]. Grade 3 pneumonitis after VMAT was observed in three patients (20.0%); however, no patients died of pulmonary toxicity. VMAT appears to be relatively safe for patients with MPM after EPP because of the low pulmonary dose.

Updated patterns of failure after multimodality therapy for malignant pleural mesothelioma

OBJECTIVE

We have previously described patterns of failure after extrapleural pneumonectomy and multimodality therapy for malignant pleural mesothelioma and sought to update our results with a larger cohort of recent patients.

METHODS

A total of 169 patients underwent extrapleural pneumonectomy without preoperative chemotherapy between 2001 and 2010. Data for treatment, recurrence, and survival were determined from medical records. A thoracic radiologist reviewed postoperative computed tomography or positron emission tomography computed tomography scans to determine sites of recurrence. Time to recurrence was estimated by the Kaplan-Meier method. Rates were compared using the Fisher exact test.

RESULTS

The median age of patients was 62 years. Histology on final pathology was epithelial for 104 patients (62%) and nonepithelial for 65 patients (38%). A total of 132 patients (78%) received heated intraoperative chemotherapy; 77 patients (45%) received adjuvant chemotherapy, and 71 patients (42%) received adjuvant radiation therapy. Most chemotherapy regimens included platinum or pemetrexed. Median radiation therapy dose was 54 Gy. Among 158 evaluable patients, a recurrence developed in 118 (75%). Median follow-up was 83 months, median time to recurrence was 13.1 months, and median survival was 15 months. Sites of first recurrence were in the ipsilateral hemithorax or mediastinum for 54% of patients, in the abdomen for 39% of patients, in the contralateral hemithorax for 28% of patients, and in other distant sites for 5% of patients. Some patients had simultaneous recurrences in multiple sites.

CONCLUSIONS

The most common site of recurrence after extrapleural pneumonectomy and planned multimodality therapy remains the ipsilateral hemithorax (including mediastinum), and true distant failure (other than the abdomen or contralateral hemithorax) remains unusual. The distribution of recurrences is strikingly similar to our prior report.

Novel induction therapies for pleural mesothelioma

Malignant mesothelioma is becoming increasingly common, and rates of diagnosis are expected to continue to increase in the coming years because of the extensive use of asbestos in industrialized countries and the long time interval between exposure and onset of disease. Although much research has been done on the optimal treatment for this disease, the overall prognosis remains grim. The main components of therapy are surgery, chemotherapy, and radiation therapy, but there is controversy in the literature about the optimal inclusion and sequencing of these treatments, as each has unique risk profiles. We have developed a new Surgery for Mesothelioma After Radiation Therapy protocol consisting of induction-accelerated hemithoracic radiation followed by extrapleural pneumonectomy. The rationale behind this protocol is to maximize both the tumoricidal and immunogenic potential of the radiotherapy while minimizing the radiation toxicity to the ipsilateral lung. Our initial trial demonstrated the feasibility of this approach and has shown encouraging results in patients with epithelial histology. In this article, we reviewed the current literature on induction chemotherapy for mesothelioma as well as described the Surgery for Mesothelioma After Radiation Therapy protocol and upcoming studies of novel induction therapies for mesothelioma.

Spinal cord ischemia resulting in paraplegia following extrapleural pneumonectomy

A patient undergoing radical extrapleural pneumonectomy for epithelioid malignant mesothelioma developed acute paraplegia postoperatively related to long-segment spinal cord ischemia. The usual area of concern for this complication is the T9 to T12 area where the artery of Adamkiewicz is most likely to originate. In this patient, there was ligation of only upper thoracic, ipsilateral segmental arteries from the T3 to T6 level, yet he still developed paraplegia. Our hypothesis is variant mid-thoracic vascular anatomy. Previously unreported, to our knowledge, this should be understood as a rare complication of this surgery.

Management of malignant pleural mesothelioma-The European experience

Management of malignant pleural mesothelioma (MPM) remains a clinical challenge and the incidence of the disease will continue to increase worldwide. Several aspects of mesothelioma treatment are discussed controversially, in particular, regarding extent and best type of surgery, radiotherapy, and the role of neoadjuvant or adjuvant treatment. However, best survival data is reported from groups using multimodality treatment including macroscopic complete resection (MCR) achieved by either extrapleural pneumonectomy (EPP) or (extended) pleurectomy/decortication for patients qualifying from the tumor biology, stage, and patient's performance status and comorbidities. Several aspects have to be considered during surgery but morbidity and mortality have been reduced at experienced centres. The final analysis of extended selection algorithms is pending.

Surgical management of malignant pleural mesothelioma: impact of surgery on survival and quality of life-relation to chemotherapy, radiotherapy, and alternative therapies

Introduction. Malignant pleural mesothelioma (MPM) is an aggressive cancer arising from pleural mesothelium. Surgery aims to either cure the disease or control the symptoms. Two surgical procedures exist: extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D). In this systematic review we assess current evidence on safety and efficacy of surgery. Methods. Five electronic databases were reviewed from January 1990 to January 2013. Studies were selected according to a predefined protocol. Primary endpoint was overall survival. Secondary endpoints included quality of life, disease-free survival, disease recurrence, morbidity, and length of hospital stay. Results. Sixteen studies were included. Median survival ranged from 8.1 to 32 months for P/D and from 6.9 to 46.9 months for EPP. Perioperative mortality was 0%–9.8% and 3.2%–12.5%, respectively. Perioperative morbidity was 5.9%–55% for P/D and 10%–82.6% for EPP. Average length of stay was 7 days for P/D and 9 days for EPP. Conclusion. Current evidence cannot definitively answer which procedure (EPP or P/D) is more beneficial in terms of survival and operative risks. This systematic review suggests that surgery in the context of trimodality therapy offers acceptable perioperative outcomes and long-term survival. Centres specialising in MPM management have better results.

WITHDRAWN: Is there life after the Mesothelioma and Radical Surgery trial? Does extrapleural pneumonectomy still have a role in the management of pleural mesothelioma? A 13-year, single-center experience

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Systematic review of trimodality therapy for patients with malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive form of cancer arising from the pleural mesothelium. Trimodality therapy (TMT) involving extrapleural pneumonectomy with neoadjuvant or adjuvant chemotherapy and adjuvant radiotherapy is a recognized treatment option with a curative intent. Despite encouraging results from institutional studies, TMT in the treatment of MPM remains controversial. The present systematic review aims to assess the safety and efficacy of TMT in the current literature.

METHODS

A systematic review was performed using five electronic databases from 1 January 1985 to 1 October 2012. Studies were selected independently by two reviewers according to predefined selection criteria. The primary endpoint was overall survival. Secondary endpoints included disease-free survival, disease recurrence, perioperative morbidity and length of stay.

RESULTS

Sixteen studies were included for quantitative assessment, including one randomized controlled trial and five prospective series. Median overall survival ranged from 12.8-46.9 months. Disease-free survival ranged from 10-16.3 months. Perioperative mortality ranged from 0-12.5%. Overall perioperative morbidity ranged from 50-82.6% and the average length of stay was 9-14 days.

CONCLUSIONS

Outcomes of patients who underwent TMT in the current literature appeared to be inconsistent. Four prospective series involving a standardised treatment regimen with neoadjuvant chemotherapy indicated encouraging results based on intention-to-treat analysis. However, a small study assessing the feasibility of conducting a randomized controlled trial for TMT versus conservative treatment reported poor short- and long-term outcomes for patients who underwent pneumonectomy. Overall, results of the present systematic review suggest TMT may offer acceptable perioperative outcomes and long-term survival in selected patients treated in specialized centers.

Role of new radiation techniques in the treatment of pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm arising from the surface serosal cells of the pleural cavity. Surgery remains the main therapeutic standard in the treatment of MPM with the goal of complete gross cytoreduction of the tumor. Because MPM is a diffuse disease affecting the entire mesothelial lining of the hemithorax, surgery alone can rarely achieve adequate tumor-free resection margins. The surgical choices are pleurectomy/decortication (P/D) or extrapleural pneumonectomy (EPP). Radiotherapy (RT) is usually applied postoperatively with the aim to improve local control. However, the efficacy of RT is limited by the large volume of the target to be irradiated (tumor and pleural cavity) and the radiosensitivity of the nearby organs (heart, liver, lung, spinal cord, and esophagus). These factors have historically limited the effective radiation doses that can be given to the patient. There is no role for radical RT alone, but the role of RT as part of multimodality therapy is discussed. After EPP adjuvant RT to the entire hemithorax can reduce the recurrence rate and is well tolerated if strict limits to the dose to contralateral lung are applied: the V20 and V5 (the percent volume of the lung receiving more than 20Gy and 5Gy of radiation) correlate with increased lung toxicity. The use of modern sophisticated techniques allows good target coverage, more conformal high dose delivery, and clinically relevant normal tissue sparing.

Multimodal therapy of malignant pleural mesothelioma: is the replacement of radical surgery imminent?

OBJECTIVES

Malignant pleural mesothelioma (MPM) remains an aggressive thoracic malignancy associated with poor prognosis. There is no standard treatment regimen, and particularly, the impact of radical surgery remains controversial. The main goal of our retrospective single-centre study was to evaluate the surgical and non-surgical treatment modalities applied at our division regarding their effect on the patient's survival.

METHODS

During the last decade, 82 patients with histologically confirmed MPM were treated at our division. The complete clinical records of 61 patients were eligible for statistical evaluation.

RESULTS

There were 14 women (23%) and 47 men (77%) with a mean age of 63.7 years. Epitheloid subtype was found in 48 patients (78.7%), sarcomatoid in 3 (4.9%) and biphasic in 10 (16%). Surgery as the first treatment modality was performed in 44 patients (72.1%). Pleurectomy/decortication was done in 28 cases (45.9%), extended pleurectomy/decortication was performed in 13 (21.3%) and extrapleural pneumonectomy in 3 (4.9%). Additional intraoperative photodynamic therapy was administered in 20 patients, 34 underwent chemotherapy (55.7%) and 12 had radiotherapy (19.7%). Mean survival time for the collective was 18.3 months. Five-year survival was 17% in the epitheloid histology group, where patients treated with chemotherapy alone yielded a significant increase in survival (P = 0.049), and those with other subtypes survived for a maximum of 20.6 months.

CONCLUSIONS

Chemotherapy and pleurectomy/decortication can extend the survival time of patients with MPM remarkably. The adequate treatment options have to be tailored to the specific particular needs of each patient considering histological subtype, tumour stage and patient's individual functional assessment as well as comorbidity.

An overview of neoadjuvant chemotherapy in the multimodality treatment of malignant pleural mesothelioma

Malignant Pleural Mesothelioma (MPM) is an aggressive tumour with poor prognosis and increasing incidence in industrialized countries because of the previous widespread exposure to asbestos fibres and to the long lag period from time of exposure and the diagnosis of the disease. MPM shows high refractoriety to systemic treatment, single-modality treatment was generally ineffective and did not achieve higher results than supportive care. The incidence of local and distant recurrences after surgery remains high and that was the reason for many centres to perform combined treatments. In the attempt of reducing the incidence of local recurrences, a multimodality approach with surgery followed by adjuvant radiotherapy was explored. Extrapleural pneumonectomy (EPP) allows higher doses of radiotherapy to the whole hemithorax by avoiding pulmonary toxicity and the results of this approach is a significant reduction of loco-regional relapses; although, extrathoracic metastasis represent a major problem in the management of the disease because of the impact on overall survival. The success with surgical resection after neoadjuvant chemotherapy in stage IIIA lung cancer has been the impetus for several groups to apply this strategy in MPM aiming at reducing the incidence of distant relapse after surgery. Platinum-based chemotherapy plus gemcitabine or pemetrexed for 3-4 cycles followed by surgery and postoperative high-dose radiotherapy showed the best results in terms of overall and progression free survival. This review will focus on the main clinical studies and overview the results of different chemotherapy regimens in the neoadjuvant treatment of MPM.

Adjuvant intensity-modulated proton therapy in malignant pleural mesothelioma. A comparison with intensity-modulated radiotherapy and a spot size variation assessment

PURPOSE

Intensity-modulated radiation therapy (IMRT) is the state-of-the-art treatment for patients with malignant pleural mesothelioma (MPM). The goal of this work was to assess whether intensity-modulated proton therapy (IMPT) could further improve the dosimetric results allowed by IMRT.

PATIENTS AND METHODS

We re-planned 7 MPM cases using both photons and protons, by carrying out IMRT and IMPT plans. For both techniques, conventional dose comparisons and normal tissue complication probability (NTCP) analysis were performed. In 3 cases, additional IMPT plans were generated with different beam dimensions.

RESULTS

IMPT allowed a slight improvement in target coverage and clear advantages in dose conformity (p < 0.001) and dose homogeneity (p = 0.01). Better organ at risk (OAR) sparing was obtained with IMPT, in particular for the liver (D(mean) reduction of 9.5 Gy, p = 0.001) and ipsilateral kidney (V(20) reduction of 58%, p = 0.001), together with a very large reduction of mean dose for the contralateral lung (0.2 Gy vs 6.1 Gy, p = 0.0001). NTCP values for the liver showed a systematic superiority of IMPT with respect to IMRT for both the esophagus (average NTCP 14% vs. 30.5%) and the ipsilateral kidney (p = 0.001). Concerning plans obtained with different spot dimensions, a slight loss of target coverage was observed along with sigma increase, while maintaining OAR irradiation always under planning constraints.

CONCLUSION

Results suggest that IMPT allows better OAR sparing with respect to IMRT, mainly for the liver, ipsilateral kidney, and contralateral lung. The use of a spot dimension larger than 3 × 3 mm (up to 9 × 9 mm) does not compromise dosimetric results and allows a shorter delivery time.

Extrapleural pneumonectomy for primary pleural mullerian tumor in a young woman

We present a case of a low-grade mullerian tumor of right pleural origin in a 23-year-old woman treated with an aggressive multimodal treatment paradigm. This tumor is heretofore undescribed in the medical literature. She received induction therapy of carboplatin and paclitaxel with minimal response, then had a maximally cytoreductive right extrapleural pneumonectomy. She subsequently underwent intensity-modulated radiotherapy to the right hemithorax. We propose a treatment paradigm for this previously undescribed primary pleural mullerian tumor.

Intensity-modulated radiotherapy after extrapleural pneumonectomy in the combined-modality treatment of malignant pleural mesothelioma

INTRODUCTION

Local therapy is becoming increasingly important as a part of the definitive treatment for malignant pleural mesothelioma after extrapleural pneumonectomy (EPP) because of the emergence of trimodality therapy consisted of chemotherapy, EPP, and adjuvant radiotherapy. Herein, we explore the current evidence and indications for adjuvant intensity-modulated radiotherapy (IMRT), as well as how to further improve this technique and adapt new technology in the delivering adjuvant radiotherapy in the setting of trimodality therapy.

METHODS

A systematic review of relevant studies identified through PubMed, ISI Web of Knowledge (Web of Science), the Cochrane Library, and the National Guideline Clearinghouse search engines was performed.

RESULTS

Local control remains poor despite the inclusion of conventional adjuvant radiation therapy in trimodality therapy. This can be improved by the delivery of adjuvant IMRT. However, IMRT can be associated with severe pulmonary toxicity if the radiation dose to the remaining lung is not kept to a very low level. This is especially true when patients are receiving chemotherapy. New advances in technology can allow for lower doses to the contralateral lung, decreased treatment delivery time, and improved target dose coverage.

CONCLUSION

Excellent local control can be achieved through adjuvant IMRT after EPP for malignant pleural mesothelioma. Severe pulmonary toxicity may be avoided by setting stringent dose constraints for the contralateral lung. This can be aided by the advances in technology. Post-treatment surveillance may be reliably conducted by periodical [18F]-fluorodeoxyglucose-positron emission tomography imaging.

The evolution of multimodality therapy for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare neoplasm of the pleural surfaces that has been associated with asbestos exposure. MPM generally spreads locally along the ipsilateral pleura, especially at presentation, with distant metastatic disease typically seen only in the later stages of the disease course. As such, surgical resection and other local therapies have long been pursued as a primary form of treatment. Surgical options include debulking of the pleura by pleurectomy/decortication (P/D) or a more aggressive extrapleural pneumonectomy (EPP) which also involves removal of the lung, diaphragm, and involved pericardium. Even after major resection, MPM almost always recurs locally and has a poor prognosis. As such, many groups have pursued multimodality therapy, treating resectable patients with EPP, along with hemithoracic radiation to decrease the risk of local recurrence and chemotherapy to decrease the risk of distant metastatic disease. However, EPP is associated with significant morbidity and mortality, and many patients are not candidates for EPP due to underlying comorbid medical conditions. Additionally, many patients are unable to tolerate complete courses of adjuvant therapy after EPP. A large, multicenter retrospective analysis comparing EPP to P/D demonstrated better outcomes among those who underwent P/D. One challenge associated with P/D has been the delivery or radiation to the removed pleura with an intact lung. Yet, advances in radiation technique have allowed the exploration of high-dose radiation therapy after P/D. The ideal timing of chemotherapy relative to surgery and the role of intracavitary chemotherapy continue to be controversial issues. Clearly, MPM requires a multidisciplinary approach and, due to the myriad of open questions, much effort continues to focus on identifying the optimal combination of surgery, chemotherapy, and radiation.

Summary of prognostic factors and patient selection for extrapleural pneumonectomy in the treatment of malignant pleural mesothelioma

BACKGROUND

Extrapleural pneumonectomy (EPP) has been shown to improve long-term survival outcomes in selected patients with malignant pleural mesothelioma (MPM). The present study aimed to evaluate potential prognostic factors on overall survival for patients who underwent EPP for MPM and to examine the patient selection process in major referral centers that perform EPP.

METHODS

A systematic review of the current literature was performed using 5 electronic databases. Relevant studies with prognostic data on overall survival for patients with MPM treated by EPP were included for review. Two reviewers independently assessed each included study.

RESULTS

A total of 17 studies from 13 institutions containing the most updated and complete data on prognostic factors for patients with MPM who underwent EPP were included for review. A number of quantitative, clinical, and treatment-related factors were identified to have significant impact on overall survival.

CONCLUSIONS

Patients with nonepithelial MPM and nodal involvement have consistently demonstrated to have a worse prognosis after EPP. Their eligibility as candidates for EPP should be questioned. The preoperative patient selection process currently differs greatly between institutions and should focus on identifying patients with nonepithelial histologic subtypes and nodal involvement to exclude them as EPP surgical candidates in the future.

What is the role of radiotherapy in malignant pleural mesothelioma?

OBJECTIVE

A review of the evidence supporting the use of radiotherapy in patients with mesothelioma was performed.

METHODS

Relevant publications were searched for on Medline.

RESULTS

In a Medline search on radiotherapy and mesothelioma, 611 hits were obtained. A limited number of prospective phase II trials of radiotherapy as part of trimodality protocols for early disease and in the palliation of pain were found, along with three small randomized controlled trials of port-site prophylaxis.

CONCLUSION

No randomized data exist to support the use of radiotherapy after radical surgery, although there are a large number of publications describing its use as an integral part of therapy, including seven phase II studies. One ongoing trial is randomizing patients to radiotherapy or not after extrapleural pneumonectomy. None of these studies provided any assessment of radiotherapy independent of the other modalities investigated, nor did any formally assess intensity-modulated radiotherapy. There have been several reports of excessive toxicity with this technique, and its use should be limited to phase I studies until the basis of this toxicity is better understood. Three trials have looked at port-site prophylaxis, one supporting its use and two showing no evidence of benefit. Two studies addressed pain control prospectively, one showing definite but short-lived benefits. Implications. Radiotherapy is widely used in treating mesothelioma with little supporting evidence. More randomized trials are required to justify this use in all three common settings for its use.

A systematic review of extrapleural pneumonectomy for malignant pleural mesothelioma

INTRODUCTION

The primary objective of the present systematic review was to evaluate the safety and efficacy of extrapleural pneumonectomy (EPP) for patients with malignant pleural mesothelioma.

METHODS

A systematic review of relevant studies identified through five online search databases was performed. Two reviewers independently appraised each study.

RESULTS

Thirty-four of 58 relevant studies from 26 institutions containing the most updated data were evaluated for survival and perioperative outcomes after EPP. The median overall survival varied from 9.4 to 27.5 months, and 1-, 2-, and 5-year survival rates ranged from 36 to 83%, 5 to 59%, and 0 to 24%, respectively. Overall perioperative mortality rates ranged from 0 to 11.8%, and the perioperative morbidity rates ranged from 22 to 82%. Quality of life assessments from three studies reported improvements in nearly all domains at 3 months postoperatively. Patients who underwent trimodality therapy involving EPP and adjuvant chemoradiotherapy had a median overall survival of 13 to 23.9 months.

DISCUSSIONS

The current evidence suggests that selected patients with malignant pleural mesothelioma may benefit from EPP, especially when combined with neoadjuvant or adjuvant chemotherapy and adjuvant radiotherapy.

Intensity-Modulated Radiation Therapy with Simultaneous Integrated Boost in Unresected Left-Sided Pleural Mesothelioma: A Case Report

A 77-year-old male patient with unresected malignant pleural mesothelioma, clinical stage T3N0M0 according to the New International Staging System for Diffuse Malignant Pleural Mesothelioma, received intensity-modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) after 6 cycles of chemotherapy with cisplatin and pemetrexed. SIB-IMRT delivered 40.5 Gy (1.5 Gy/fraction) to the left pleura and 50 Gy (1.85 Gy/fraction) to the sites of macroscopic disease. Radiotherapy was well tolerated. Two months after the end of radiotherapy the patient showed grade 2 lung toxicity (febrile episodes accompanied by dry cough) that was successfully treated with steroid therapy. Local control lasted for 2 years after SIB-IMRT. Then the tumor recurred marginally to the radiation field and the patient underwent chemotherapy with pemetrexed. Three years from the diagnosis, the patient is alive and in good general condition. He only takes prednisone 5 mg/daily for exertional dyspnea. To the best of our knowledge this is the first reported use of SIB-IMRT in unresected malignant pleural mesothelioma. Considering the dosimetric advantages of SIB-IMRT and the clinical results observed in our patient, additional evaluation of this technique seems justified.

Malignant mesothelioma

INTRODUCTION

Mesothelioma is a malignant tumour of the pleura or peritoneum caused by asbestos. It is increasing in frequency and the prognosis remains grim, with average survival around 1 year.

SOURCES OF DATA

Medical literature and personal experience.

AREAS OF AGREEMENT

Amphibole fibres are far more potent than chrysotile in causing mesothelioma.

AREAS OF CONTROVERSY

A minority view suggests that mesotheliomas in those exposed to chrysotile are caused only by tremolite (an amphibole) which contaminates chrysotile. There is a hypothesis, for which evidence is weakening, that Simian virus 40 may cause mesothelioma.

GROWING POINTS

There is emerging evidence of genetic variation in susceptibility to fibre carcinogenesis. There are developments in treatment, particularly chemotherapy with pemetrexed and cisplatin which prolongs survival and helps symptoms.

AREAS TIMELY FOR DEVELOPING RESEARCH

Targeted agents for treatment are under investigation and may improve the outlook. The role of radical and palliative surgery requires clarification.