Induction chemotherapy, extrapleural pneumonectomy (EPP) and adjuvant hemi-thoracic radiation in malignant pleural mesothelioma (MPM): Feasibility and results

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Novel Insights Into Mesothelioma Therapy: Emerging Avenues and Future Prospects

Malignant mesothelioma is a rare and aggressive cancer that develops in the thin layer surrounding the mesothelium and is mainly caused by asbestos exposure. Despite improvements in patient prognosis with conventional cancer treatments, such as surgery, chemotherapy, and radiotherapy, there are still no curative treatment modalities for advanced disease. In recent years, new therapeutic avenues have been explored. Improved understanding of the mechanisms underlying the dynamic tumor interaction with the immune system has led to the development of immunotherapeutic approaches. Numerous recent clinical trials have shown a desire to develop more effective treatments that can be used to fight against the disease. Immune checkpoint inhibitors, oncolytic adenoviruses, and their combination represent a promising strategy that can be used to synergistically overcome immunosuppression in the mesothelioma tumor microenvironment. This review provides a synthesized overview of the current state of knowledge on new therapeutic options for mesothelioma with a focus on the results of clinical trials conducted in the field.

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.

Landmark Trials in the Surgical Management of Mesothelioma

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

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.

Preoperative prediction of unresectability in malignant pleural mesothelioma

OBJECTIVE

Diffuse chest wall invasion (DCWI) is a common finding in patients undergoing intended resection for malignant pleural mesothelioma. We sought to determine the incidence and preoperative predictors of this finding, and to test our anecdotal impression that contraction of the ipsilateral hemithorax is associated with DCWI.

METHODS

This was a single-institution retrospective study of 170 patients undergoing intended macroscopic complete resection for malignant pleural mesothelioma from 2014-2018. A novel metric of thoracic cage volume was calculated by preoperative chest computed tomography. Univariable analyses were performed to determine associations of preoperative variables with DCWI.

RESULTS

Macroscopic complete resection was achieved by pleurectomy/decortication in 104 patients (61%) and by extrapleural pneumonectomy in 39 patients (23%). Unresectable disease was discovered at thoracotomy in 27 (16%) of patients; 24 (14%) by DCWI and 3 (2%) by intrathoracic organ invasion. In univariable analysis, decreased ipsilateral thoracic cage volume demonstrated the strongest association with unresectability by DCWI (P = .009) with >5% decrease in thoracic cage volume representing the optimal cutoff (P = .014; area under the curve, 0.67). Other preoperative variables associated with DCWI included preoperative chest pain requiring opioids (P = .028), prior pleurodesis (P = .036), decreased forced vital capacity (P = .023), decreased ipsilateral lung perfusion by ventilation/perfusion lung scan (P = .007), and magnetic resonance imaging findings of chest wall invasion (P = .035).

CONCLUSIONS

Preoperative identification of DCWI will avoid unnecessary thoracotomy and accelerate initiation of nonsurgical therapy in malignant pleural mesothelioma. Our data suggest that contraction of thoracic cage volume has merit in predicting malignant pleural mesothelioma unresectability and should be validated in prospective studies.

Scientific Advances and New Frontiers in Mesothelioma Therapeutics

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

Return to intended oncologic treatment after surgery for malignant pleural mesothelioma

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Extra-pleural pneumonectomy

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

Multimodality treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare disease of the pleura and is largely related to asbestos exposure. Despite recent advancements in technologies and a greater understanding of the disease, the prognosis of MPM remains poor; the median overall survival rate is about 6 to 9 months in untreated patients. The main therapeutic strategies for MPM are surgery, chemotherapy, and radiation therapy (RT). The two main surgical approaches for MPM are extrapleural pneumonectomy (EPP), in which the lung is removed en bloc, and pleurectomy/decortication, in which the lung stays in situ. Chemotherapy usually consists of a platinum-based chemotherapy, such as cisplatin, often combined with a folate antimetabolite, such as pemetrexed. More recently, immunotherapy has emerged as a possible therapeutic strategy for MPM. Evidence suggests that single-modality treatments are not an effective therapeutic approach for MPM. Therefore, researchers have started to explore different multimodality treatment approaches, in which often combinations of surgery, chemotherapy, immunotherapy, and RT are investigated. There is still no definitive answer to the question of which multimodality treatment combinations are most effective in improving the poor prognosis of MPM. Research into the effects of trimodality treatment approaches have found that radical approaches such as EPP and hemithoracic RT post-EPP are less effective than was previously assumed. In general, there are still a great number of unanswered questions and unknown factors regarding the ideal treatment approach for MPM. Hopefully, more research into multimodality therapy will provide insight into which combination of treatment modalities is most effective.

A randomized phase II study of pleurectomy/decortication preceded or followed by (neo-)adjuvant chemotherapy in patients with early stage malignant pleural mesothelioma (EORTC 1205)

Radical multimodality treatment for malignant pleural mesothelioma (MPM) is controversial, with intense debate (but lack of data) about which surgical procedure to perform [extrapleural pneumonectomy (EPP) or pleurectomy/decortication (PD)], if any. In order to perform a randomized comparison, the most optimal sequence of surgery and chemotherapy should be determined. EORTC 1205 is a clinical trial randomizing between upfront surgery, followed by chemotherapy (cisplatin plus pemetrexed) and deferred surgery, following neoadjuvant chemotherapy in early stage (T1-3 N0-2 M0) MPM (irrespective of histological subtype). The surgical procedure performed is (extended) pleurectomy/decortication (e-PD), which is promoted as an alternative for EPP, but lacks standardization. Primary outcome parameter is successful completion of multimodality treatment; secondary outcome parameters are surgical quality parameters (in order to standardize the procedure), progression free survival (PFS) and overall survival (OS), treatment-failure free survival, operative morbidity and mortality, toxicity and safety.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Biomarker-Integrated Neoadjuvant Dasatinib Trial in Resectable Malignant Pleural Mesothelioma

INTRODUCTION

Window of opportunity trials in malignant pleural mesothelioma (MPM) are challenging but can yield important translational information about a novel agent.

METHODS

We treated patients with MPM (N = 24) with 4 weeks of oral dasatinib followed by surgery with or without radiotherapy and then an optional 2 years of maintenance dasatinib. The primary end point was biomarker modulation of phosphorylated (p) Src^Tyr419.

RESULTS

For all patients, the median progression-free survival (PFS) was 7.5 months and the median overall survival was 19.1 months. No significant responses were seen after 4 weeks of dasatinib therapy; however, modulation of median p-Src^Tyr419 immunohistochemistry (IHC) scores was seen: the median pretreatment score was 70 (interquartile range 37.5-110), and the median posttreatment score was 41.9 (interquartile range 4.2-60) (p = 0.004). A decrease in p-Src^Tyr419 levels after dasatinib correlated with improved median PFS (6.9 months versus 0.94 months [p = 0.03]), suggesting that p-Src^Tyr419 is a viable pharmacodynamic biomarker for dasatinib in MPM. Platelet-derived growth factor receptor (PDGFR) pathway analysis correlated high PDGFR beta [PDGFRB) level (in the cytoplasm [hazard ratio] (HR) = 2.54, p = 0.05], stroma [HR = 2.79, p = 0.03], and nucleus [HR = 6.79, p = 0.023]) with a shorter PFS. Low (less than the median) cytoplasmic p-PDGFR alpha IHC levels were predictive of a decrease in positron emission tomography/computed tomography standard uptake values levels after dasatinib therapy (p = 0.04), whereas higher-than-median IHC scores of PDGFRB (cytoplasmic [HR = 2.8, p = 0.03] and nuclear [HR = 6.795, p = 0.02]) were correlated with rising standard uptake values levels.

CONCLUSIONS

In conclusion, there was no significant efficacy signal, and dasatinib monotherapy will not continue to be studied in MPM. However, our study demonstrated that PDGFR subtypes (platelet-derived growth factor receptor alpha and PDGFRB) may have differential roles in prognosis and resistance to antiangiogenic tyrosine kinase inhibitors and are important potential therapeutic targets that require further investigation.

Review of malignant pleural mesothelioma survival after talc pleurodesis or surgery

Malignant pleural mesothelioma (MPM) is an aggressive tumor and the prognosis is still dismal despite the various proposed multimodal treatment plans. Currently, new palliative treatments, such as talc pleurodesis, are being explored besides traditional surgery. This review reports survival rates after talc pleurodesis in comparison to surgery in patients with malignant pleural mesothelioma. A systematic literature search yielded 49 articles eligible for this review. The mean survival in the talc pleurodesis group was 14 months compared to 17 and 24 months for the pleurectomy decortication (P/D) group and extrapleural pneumonectomy (EPP) group, respectively. Few studies reported on the 1-, 2-year overall survival for the talc pleurodesis group and the results were very heterogeneous. The pooled 1-year overall survival for the P/D and EPP groups were 55% [credibility limits (CL): 21-87%] and 67% (CL: 3-89%), the pooled 2-year overall survival were 32% (CL: 8-63%) and 36% (CL: 8-54%), respectively. The pooled 1- and 2-year survival for surgery independently from the type of surgery were 62% (CL: 38-84%) and 34% (CL: 16-54%). There was significant heterogeneity in all the analyses. This review shows that there is limited research on the survival rate after talc pleurodesis compared to surgery in the treatment of malignant pleural mesothelioma. A comparison study is necessary to accurately assess the best way to treat MPM patients, including assessment of the quality of life after treatment as an outcome measure.

Consensus Report of the 2015 Weinman International Conference on Mesothelioma

On November 9 and 10, 2015, the International Conference on Mesothelioma in Populations Exposed to Naturally Occurring Asbestiform Fibers was held at the University of Hawaii Cancer Center in Honolulu, Hawaii. The meeting was cosponsored by the International Association for the Study of Lung Cancer, and the agenda was designed with significant input from staff at the U.S. National Cancer Institute and National Institute of Environmental Health Sciences. A multidisciplinary group of participants presented updates reflecting a range of disciplinary perspectives, including mineralogy, geology, epidemiology, toxicology, biochemistry, molecular biology, genetics, public health, and clinical oncology. The group identified knowledge gaps that are barriers to preventing and treating malignant mesothelioma (MM) and the required next steps to address barriers. This manuscript reports the group’s efforts and focus on strategies to limit risk to the population and reduce the incidence of MM. Four main topics were explored: genetic risk, environmental exposure, biomarkers, and clinical interventions. Genetics plays a critical role in MM when the disease occurs in carriers of germline BRCA1 associated protein 1 mutations. Moreover, it appears likely that, in addition to BRCA1 associated protein 1, other yet unknown genetic variants may also influence the individual risk for development of MM, especially after exposure to asbestos and related mineral fibers. MM is an almost entirely preventable malignancy as it is most often caused by exposure to commercial asbestos or mineral fibers with asbestos-like health effects, such as erionite. In the past in North America and in Europe, the most prominent source of exposure was related to occupation. Present regulations have reduced occupational exposure in these countries; however, some people continue to be exposed to previously installed asbestos in older construction and other settings. Moreover, an increasing number of people are being exposed in rural areas that contain noncommercial asbestos, erionite, and other mineral fibers in soil or rock (termed naturally occurring asbestos [NOA]) and are being developed. Public health authorities, scientists, residents, and other affected groups must work together in the areas where exposure to asbestos, including NOA, has been documented in the environment to mitigate or reduce this exposure. Although a blood biomarker validated to be effective for use in screening and identifying MM at an early stage in asbestos/ NOA-exposed populations is not currently available, novel biomarkers presented at the meeting, such as high mobility group box 1 and fibulin-3, are promising. There was general agreement that current treatment for MM, which is based on surgery and standard chemotherapy, has a modest effect on the overall survival (OS), which remains dismal. Additionally, although much needed novel therapeutic approaches for MM are being developed and explored in clinical trials, there is a critical need to invest in prevention research, in which there is a great opportunity to reduce the incidence and mortality from MM.

Long-Term Survival Outcomes of Cancer-Directed Surgery for Malignant Pleural Mesothelioma: Propensity Score Matching Analysis

Purpose

Small observational studies have shown a survival advantage to undergoing cancer-directed surgery for malignant pleural mesothelioma (MPM); however, it is unclear if these results are generalizable. Our purpose was to evaluate survival after treatment of MPM with cancer-directed surgery and to explore the effect surgery interaction with chemotherapy or radiation therapy on survival by using the National Cancer Database.

Patients and Methods

Patients with microscopically proven MPM were identified within the National Cancer Database (2004 to 2014). Propensity score matching was performed 1:2 and among this cohort, a Cox proportional hazards regression model was used to identify predictors of survival. Median survival was calculated by using the Kaplan-Meier method.

Results

Of 20,561 patients with MPM, 6,645 were identified in the matched cohort, among whom 2,166 underwent no therapy, 2,015 underwent chemotherapy alone, 850 underwent cancer-directed surgery alone, 988 underwent surgery with chemotherapy, and 274 underwent trimodality therapy. The remaining 352 patients underwent another combination of surgery, radiation, or chemotherapy. Thirty-day and 90-day mortality rates were 6.3% and 15.5%. Cancer-directed surgery, chemotherapy, and radiation therapy were independently associated with improved survival (hazard ratio, 0.77, 0.74, and 0.88, respectively). Stratified analysis revealed that surgery-based multimodality therapy demonstrated an improved survival compared with surgery alone, with no significant difference between surgery-based multimodality therapies; however, the largest estimated effect was when cancer-directed surgery, chemotherapy, and radiation therapy were combined (hazard ratio, 0.52). For patients with the epithelial subtype who underwent trimodality therapy, median survival was extended from 14.5 months to 23.4 months.

Conclusion

MPM is an aggressive and rapidly fatal disease. Surgery-based multimodality therapy was associated with improved survival and may offer therapeutic benefit among carefully selected patients.

A Randomized Phase II Trial of Adjuvant Galinpepimut-S, WT-1 Analogue Peptide Vaccine, After Multimodality Therapy for Patients with Malignant Pleural Mesothelioma

Purpose: Determine the 1-year progression-free survival (PFS) rate among patients with malignant pleural mesothelioma (MPM) receiving the WT1 peptide vaccine galinpepimut-S after multimodality therapy versus those receiving control adjuvants.Experimental Design: This double-blind, controlled, two center phase II trial randomized MPM patients after surgery and another treatment modality to galinpepimut-S with GM-CSF and Montanide or GM-CSF and Montanide alone. An improvement in 1-year PFS from 50% to 70% was the predefined efficacy threshold, and 78 patients total were planned. The study was not powered for comparison between the two arms.Results: Forty-one patients were randomized. Treatment-related adverse events were mild, self-limited, and not clinically significant. On the basis of a stringent prespecified futility analysis (futility = ≥10 of 20 patients on one arm experiencing progression < 1 year), the control arm closed early. The treatment arm was subsequently closed because of the resultant unblinding. The PFS rate at 1 year from beginning study treatment was 33% and 45% in the control and vaccine arms, respectively. Median PFS was 7.4 months versus 10.1 months and median OS was 18.3 months versus 22.8 months in the control and vaccine arms, respectively.Conclusions: The favorable safety profile was confirmed. PFS and OS were greater in those who received vaccine, but the trial was neither designed nor powered for comparison between the arms. On the basis of these promising results, the investigators are planning a larger randomized trial with greater statistical power to define the optimal use and benefit of galinpepimut-S in the treatment of MPM. Clin Cancer Res; 23(24); 7483-9. ©2017 AACR.

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.

Low-dose photon irradiation induces invasiveness through the SDF-1α/CXCR4 pathway in malignant mesothelioma cells

Background

Low-dose photon irradiation has repeatedly been suspected to increase a risk of promoting local recurrence of disease or even systemic dissemination. The purpose of this study was to investigate the motility of malignant pleural mesothelioma (MPM) cell lines after low-doses of photon irradiation and to elucidate the mechanism of the detected phenotype.

Methods

H28 and H226 MPM cells were examined in clonogenic survival experiments and migration assays with and without various doses of photon and carbon ion irradiation. C-X-C chemokine receptor type 4 (CXCR4), SDF-1α, β₁ integrin, α₃ integrin, and α₅ integrin expressions were analyzed by quantitative FACS analysis, ELISA and western blots. Apoptosis was assessed via Annexin-V-staining.

Results

The migration of MPM cells was stimulated by both fetal bovine serum and by stromal cell-derived factor 1α (SDF-1α). Low doses of photon irradiation (1 Gy and 2 Gy) suppressed clonogenicity, but promoted migration of both H28 and H226 cells through the SDF-1α/CXCR4 pathway. Hypermigration was inhibited by the administration of CXCR4 antagonist, AMD3100. In contrast, corresponding doses of carbon ion irradiation (0.3 Gy and 1 Gy) suppressed clonogenicity, but did not promote MPM cell migration.

Conclusion

Our findings suggest that the co-administration of photon irradiation and the CXCR4-antagonist AMD3100 or the use of carbon ions instead of photons may be possible solutions to reduce the risk of locoregional tumor recurrence after radiotherapy for MPM.

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.

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.

Trimodality strategy for treating malignant pleural mesothelioma: results of a feasibility study of induction pemetrexed plus cisplatin followed by extrapleural pneumonectomy and postoperative hemithoracic radiation (Japan Mesothelioma Interest Group 0601 Trial)

PURPOSE

We conducted a prospective multi-institutional study to determine the feasibility of trimodality therapy (TMT) comprising induction chemotherapy followed by extrapleural pneumonectomy (EPP) and radiation therapy in Japanese patients with malignant pleural mesothelioma (MPM).

METHODS

Major eligibility criteria were histologically confirmed diagnosis of MPM, including clinical subtypes T0-3, N0-2, M0 disease; no prior treatment for the disease; age 20-75 years; Eastern Cooperative Oncology Group performance status 0 or 1; predicted postoperative forced expiratory volume >1000 ml in 1 s; written informed consent. Treatment methods comprised induction chemotherapy using pemetrexed (500 mg/m(2)) plus cisplatin (60 mg/m(2)) for three cycles, followed by EPP and postoperative hemithoracic radiation therapy (54 Gy). Primary endpoints were macroscopic complete resection (MCR) rate for EPP and treatment-related mortality for TMT.

RESULTS

Forty-two eligible patients were enrolled: median age 64.5 (range 43-74) years; M:F = 39:3, clinical stage I:II:III = 14:13:15; histological type epithelioid were sarcomatoid; biphasic; others = 28:1:9:4. Of 42 patients, 30 completed EPP with MCR and 17 completed TMT. The trial met the primary endpoints, with an MCR rate of 71 % (30/42) and treatment-related mortality of 9.5 % (4/42). Overall median survival time and 2-year survival rate for 42 registered patients were 19.9 months and 42.9 %, respectively. Two-year relapse-free survival rate of 30 patients who completed EPP with MCR was 37.0 %.

CONCLUSION

This phase II study met the predefined primary endpoints, but its risk/benefit ratio was not satisfactory.

Modern management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a deadly disease that produces a significant worldwide health care burden. The majority of cases are associated with prior asbestos exposure, but recent studies have identified a possible genetic predisposition in a minority of patients. Historically, obtaining a pathologic diagnosis of MPM was challenging, but with current pathological techniques, a secure diagnosis is possible in the majority of patients. Curative therapy for MPM remains elusive, and the primary treatment option for fit patients is platinum-based chemotherapy. Encouraging recent reports suggest that there may be a benefit to the addition of bevacizumab to standard chemotherapy as well as with the use of immune checkpoint inhibitors in MPM. Selected patients may be considered for aggressive surgical approaches, but there is considerable controversy regarding the true benefit of surgery and multimodality therapy in this disease.

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.

Local and systemic therapies for malignant pleural mesothelioma

OPINION STATEMENT

Malignant pleural mesothelioma (MPM) is a challenging disease to treat with median overall survival times ranging between 9-17 months for all stages of disease. Recent clinical trials have improved our understanding of the biology of MPM. However, survival results are still not ideal. For early-stage MPM, patients should be evaluated for trimodality therapy in an experienced cancer center. If treating off-protocol, MPM patients should receive a surgical staging evaluation. The decision to proceed with surgical resection also should be considered after an extensive and thorough pulmonary and cardiac evaluation. If deemed a good surgical candidate, patients should receive surgical resection (pleurectomy/decortication or extrapleural pneumonectomy), adjuvant radiation therapy (hemithoracic external beam or intensity modulated radiation therapy), and either neoadjuvant or adjuvant chemotherapy (cisplatin-pemetrexed for 4 cycles). The optimal precise sequence of the trimodality is unclear and should be decided upon by a multidisciplinary consensus for each individual patient. In general, clinical trial participation should be encouraged. Several trials are currently underway to examine intraoperative therapies, vaccines, immunotherapy additions, and novel radiation therapy techniques. Advances in the field of MPM are reliant on participation in clinical trials and identifying biomarkers that are predictive for response to systemic therapies and prognostic for survival benefit.

Surgical Management of Malignant Pleural Mesothelioma: An Update of Clinical Evidence

To investigate the surgical management of malignant pleural mesothelioma, 2 randomized controlled trials have been completed. We discuss the findings from these trials and the current evidence of various surgical techniques to treat this challenging disease.

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.

Fast neutron radiotherapy in the treatment of malignant pleural mesothelioma

INTRODUCTION

Malignant pleural mesothelioma (MPM) is a fatal disease lacking standardized treatment. We describe the use of fast neutron radiation therapy in MPM patients referred to the Department of Radiation Oncology at the University of Washington Medical Center.

MATERIALS AND METHODS

Retrospective chart review of MPM patients receiving neutron radiotherapy treatment from 1980 to 2012.

RESULTS

A total of 30 MPM patients received fast neutron radiotherapy as part of their treatment regimen. Median age at diagnosis was 59.6 years (range, 46.6 to 72.3 y). Eighteen patients received fast neutron radiotherapy as a component of trimodality treatment. Median overall survival was 20.3 months (range, 5.5 to 73.3 mo) with 1 patient censored at 34.8 months and all other patients with confirmed dates of death. One patient receiving radiotherapy alone as a palliative measure died during radiation treatment. One patient was unable to tolerate radiotherapy and stopped before completing prescribed treatment. On univariate analysis, Brigham Stage at presentation was a significant predictor of survival (P<0.01). No significant differences in survival were observed when comparing patients who received trimodality treatment compared to those who did not.

CONCLUSIONS

Fast neutron radiotherapy may be utilized in the management of MPM patients. However, treatment with fast neutron radiotherapy did not significantly improvement outcome, even when used in a trimodality regimen.

Combination effect of photodynamic therapy using NPe6 with pemetrexed for human malignant pleural mesothelioma cells

To identify a possible new treatment modality for malignant pleural mesothelioma (MPM), we examined whether combination treatment consisting of pemetrexed chemotherapy and photodynamic therapy (PDT) using the photosensitizer NPe6, enhanced the antitumor effect in both in vitro and in vivo models. We also investigated preclinical treatment schedules. Four human malignant mesothelioma cell lines (MSTO‑211H, H2052, H2452 and H28) were assayed using the WST assay after treatment with pemetrexed and NPe6‑PDT. The treatment schedule for the combination treatment was examined using nude mice. Pemetrexed pre‑treatment enhanced the lethal effect of NPe6‑PDT in the four malignant mesothelioma cell lines, but NPe6‑PDT followed by pemetrexed treatment did not enhance cell lethality in the in vitro assay. Pemetrexed pre‑treatment did not enhance the intracellular accumulation of NPe6, which is one of the determinants of the antitumor effect of PDT. In nude mice injected with MSTO‑211H cells and then treated using a combination of pemetrexed and NPe6‑PDT (10 mg/kg NPe6, 10 J/cm(2) laser irradiation), the tumor volume decreased by 50% but subsequently increased, reaching the pre‑treatment value after 14 days. Pemetrexed treatment followed by NPe6‑PDT resulted in an 80% reduction in the tumor size and inhibited re‑growth. NPe6‑PDT followed by pemetrexed treatment resulted in a 60% reduction in tumor size but did not inhibit re‑growth. NPe6‑PDT induced the expression of thymidylate synthase (TS), which confers resistance to pemetrexed, and NPe6‑PDT followed by pemetrexed treatment did not enhance the treatment outcome in vivo. In conclusion, combination treatment, consisting of pemetrexed followed by NPe6‑PDT, should be further investigated as a new treatment modality for MPM. In the future, this combination treatment may contribute to a reduction in local recurrence and a prolonged survival period in patients with MPM.

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.

Systematic review on pleurectomy/decortication in the multimodality treatment of malignant pleural mesothelioma

SUMMARY 

Malignant pleural mesothelioma (MPM) is an aggressive tumor of pleural membranes with a dismal prognosis. Following diagnosis survival is usually less than 12 months. The treatment is therefore very often palliative. In selected cases with early stage disease surgical resection is possible. Several studies have now shown that combination treatment with chemotherapy (CHT), radiotherapy (RT) and radical surgery lead to an increased overall survival (OS). This review analyzes the long-term results of the two different types of radical surgery included in the multimodality treatment: extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D). Recent studies have shown P/D to have less morbidity with comparable or better OS compared with EPP while enabling more patients to complete multimodality treatment.

A phase II trial of prolonged, continuous infusion of low-dose gemcitabine plus cisplatin in patients with advanced malignant pleural mesothelioma

PURPOSE

Low-dose, prolonged infusion of gemcitabine has effects similar to standard doses in several cancers. We evaluated the toxicity and efficacy of low-dose gemcitabine in prolonged infusion plus cisplatin in patients with advanced pleural mesothelioma.

METHODS

Patients with mesothelioma received gemcitabine (250 mg/m(2)) in a 6-h infusion plus cisplatin (35 mg/m(2)) on days 1 and 8 every three weeks. We used the modified response evaluation criteria in solid tumours. This study is registered in clinical trials (NCT01869023).

RESULTS

We included 39 patients; 82.1 % were low risk according to the European Organisation for Research and Treatment of Cancer prognostic group. Partial response was observed in 53.8 % (21/39), stable disease in 33.3 % (13/39) and progression in 12.8 % (5/39). The median progression-free survival was 6.9 months (95 % CI 3.2-10.6 months), and the associated factors were the EORTC risk and histology. The median overall survival was 20.7 months (95 % CI 10.7-30.8 months). The functional, physical and emotional roles and dyspnoea, insomnia and pain symptom scales improved. The most commonly graded 3/4 side effects were neutropenia (24.4 %), lymphopenia (14.6 %), thrombocytopenia (14.7 %) and anaemia (12.2 %).

CONCLUSIONS

Low-dose, prolonged gemcitabine infusion plus cisplatin has acceptable toxicity and high efficacy with improved quality of life, representing an affordable regimen for the low-income population.

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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[Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity]

PURPOSE

To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.

PATIENTS AND METHODS

Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.

RESULTS

The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).

CONCLUSION

Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.

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.

Do we need a revised staging system for malignant pleural mesothelioma? Analysis of the IASLC database

INTRODUCTION

A number of staging systems have been proposed for malignant pleural mesothelioma (MPM) in the past, but few have utilized a TNM (tumor, node, metastasis) system. The International Association for the Study of Lung Cancer (IASLC) and the International Mesothelioma Interest Group (IMIG) previously developed a TNM-staging system which has been accepted by the International Union Against Cancer (UICC) and the American Joint Commission on Cancer (AJCC). The present study examines this staging system by analysing the updated IASLC database for patients with MPM.

METHODS

De-identified data from participating centres dated from 1995 to 2009 were submitted to the IASLC Statistical Center. Surgical procedures included those with a curative or palliative intent. Survival was measured from the date of pathologic diagnosis to the most recent contact or death. Endpoints included overall survival and analysis of potential prognostic factors.

RESULTS

Data was available for 3,101 patients from 15 centers, mostly from North America and Europe. After a median follow-up of 15 months, a number of clinicopathological and treatment-related prognostic factors were found to significantly influence overall survival. These included overall tumor stage based on the proposed TNM staging system, T category, N category, tumor histology, gender, age, and type of operation.

CONCLUSIONS

The IASLC database represents the largest, multicenter and international database on MPM to date. Analyses demonstrate that the proposed TNM staging system effectively distinguishes the T and N categories, but also highlight areas for potential revision in the future.