Outcome for Patients with Malignant Pleural Mesothelioma Referred for Trimodality Therapy in Western Australia

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

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

Epidemiology and Clinical Aspects of Malignant Pleural Mesothelioma

Mesothelioma is a cancer predominantly of the pleural cavity. There is a clear association of exposure to asbestos with a dose dependent risk of mesothelioma. The incidence of mesothelioma in different countries reflect the historical patterns of commercial asbestos utilisation in the last century and predominant occupational exposures mean that mesothelioma is mostly seen in males. Modern imaging techniques and advances in immunohistochemical staining have contributed to an improved diagnosis of mesothelioma. There have also been recent advances in immune checkpoint inhibition, however, mesothelioma remains very challenging to manage, especially considering its limited response to conventional systemic anticancer therapy and that no cure exists. Palliative interventions and support remain paramount with a median survival of 9-12 months after diagnosis. The epidemiology and diagnosis of mesothelioma has been debated over previous decades, due to a number of factors, such as the long latent period following asbestos exposure and disease occurrence, the different potencies of the various forms of asbestos used commercially, the occurrence of mesothelioma in the peritoneal cavity and its heterogeneous pathological and cytological appearances. This review will describe the contemporary knowledge on the epidemiology of mesothelioma and provide an overview of the best clinical practice including diagnostic approaches and management.

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.

Types of surgery post-neoadjuvant chemotherapy for pleural mesothelioma

Introduction: The surgical arm of the Mesothelioma and Radical Surgery (MARS) trial involved a multimodal approach, with combined therapy consisting of chemotherapy, complete gross resection, and radiation therapy. However, the MARS trial did not compare surgery with chemotherapy, and the survival and quality of life outcomes of this trial's surgical arm were inferior to those of the non-surgical arm. Methods for achieving complete gross resection (macroscopic complete response [MCR]) include extrapleural pneumonectomy (EPP), wherein the pleura, lung, diaphragm, and pericardium are removed en bloc, and pleurectomy/decortication (P/D), wherein the affected lung is preserved. Nonetheless, the most effective therapy remains unclear.Areas covered: Here, surgery post-neoadjuvant chemotherapy for malignant pleural mesothelioma with either EPP or P/D has been discussed, along with trimodal and bimodal therapies.Expert opinion: With the development of post-P/D radiation therapy, it is currently possible to truly compare EPP with P/D. Moreover, R0 resection cannot be achieved with either EPP or P/D; thus, both must incorporate debulking, although the two procedures are largely incompatible. Therefore, there is a need to rebuild the status of surgery as a multimodal therapy.

Intracavitary cisplatin-fibrin chemotherapy after surgery for malignant pleural mesothelioma: A phase I trial

OBJECTIVES

Intracavitary chemotherapy is a promising concept to improve local tumor control for malignant pleural mesothelioma with reported high morbidity rates. We have demonstrated that administration of cisplatin loaded to fibrin increased local drug concentration and reduced systemic toxicity in preclinical models. We present a phase I trial of intracavitary cisplatin-fibrin after surgical tumor resection.

METHODS

A total of 12 patients (75% International Mesothelioma Interest Group stage III-IV) were treated with 4 dose levels of intracavitary cisplatin-fibrin (11-44 mg/m² body surface area) in a dose-escalating design. Cisplatin-fibrin was sprayed on the resected surfaces after pleurectomy/decortication. Blood and tissue samples were taken to assess toxicity and pharmacokinetics. Patients were regularly followed up.

RESULTS

No dose-limiting toxicity was observed. Major morbidity occurred in 4 patients (33%). The 30-day and 90-day mortality were both 0%. Of 80 adverse events, 9 were classified serious, but none of these were related to study treatment. Local cisplatin concentration in the chest wall tissue was high at all dose levels (median, 46.3 μg/g [12-133 μg/g]). In serum, median cisplatin area under the concentration time curve values were always below renal toxicity levels. The median overall survival with 95% confidence interval was 21 months (10-31 months). In 1 patient with epithelioid malignant pleural mesothelioma (International Mesothelioma Interest Group stage I), there was no sign of relapse 48 months after treatment (44 mg/m² body surface area).

CONCLUSIONS

The administration of intracavitary cisplatin-fibrin is safe with favorable pharmacokinetics. Although most patients had advanced disease, long-term outcomes are comparable to other multimodal concepts. A confirmation phase II trial is ongoing.

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.

Prediction modelling using routine clinical parameters to stratify survival in Malignant Pleural Mesothelioma patients undergoing cytoreductive surgery

INTRODUCTION

Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.

METHODS

Data were collected from subjects undergoing cytoreductive surgery for MPM from specialist centers in Hyõgo, Japan, and Sydney, Australia, between 1991 and 2016. The CART model was applied using the combination of clinical variables to stratify subjects into risk groups (1 through 4); survival characteristics were then compared.

RESULTS

Two hundred eighty-nine cases were included (205 from Australia, 84 from Japan). Overall median survival was 34.6 (interquartile range: 17.5-56.1) months; median age was 63.0 (interquartile range: 57.0-67.8) years, and 83.0% (n = 240) were male. There were no clinically meaningful differences between the two cohorts. Survival across the four risk groups was significantly different (p < 0.0001); the model stratified survival well with a Harrell's concordance statistic of 0.62 (95% confidence interval: 0.57-0.66) at 36 months. The group with the longest survival (median, 82.5 months) had: no weight loss, hemoglobin > 153 g/L and serum albumin > 43 g/L at time of referral to the surgical center.

CONCLUSIONS

Using routinely available clinical variables, the CART model was able to stratify surgical patients into risk groups with statistically different survival characteristics with fair to good performance. Presence of weight loss, anemia, and low albumin should confer caution when considering surgical therapy for MPM.

Extrapleural pneumonectomy: still indicated?

The optimal treatment of malignant pleural mesothelioma (MPM) has not yet been established and is still under investigation. Surgery is one of the pillars in the multimodality approach with the purpose of removing as much as visible tumor as possible and to relieve symptoms. To date, two major surgical procedures are available for removal or debulking of MPM that is considered to be resectable: [extended (e)] pleurectomy/decortication (P/D) and extrapleural pneumonectomy (EPP). Historically, EPP was regarded as the only way to achieve a macroscopic complete resection. However, in the last years, there is a shift in literature towards (e)P/D as the preferred surgical procedure whenever possible as several retrospective studies and meta-analyses showed a similar or lower long-term survival and higher perioperative mortality and postoperative morbidity in patients who been treated with EPP. On the other hand, no randomized-controlled trials regarding surgical treatment with (e)P/D or EPP exist and therefore level A evidence favoring one surgical procedure is lacking. In this review we provide a nuanced and well-considered answer to the question whether EPP is still indicated in the surgical treatment of MPM.

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?

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.

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.

Mesothelioma in Australia: a review

The incidence of malignant mesothelioma in Australia is among the highest in the world as a result of widespread use of asbestos by industry and in construction throughout the 20th century. The risk of developing malignant mesothelioma after asbestos exposure is dose-related; a transient, low dose exposure confers a correspondingly very low risk of disease. Malignant mesothelioma is a heterogeneous disease, partly explaining the limited role of biomarkers in screening and diagnosis. The prognosis remains poor, and early advice on medico-legal compensation and a collaborative team approach to managing malignant mesothelioma are both essential. Chemotherapy can have a modest treatment effect in some people. New therapies, such as immunotherapy, do not yet have a defined role in the treatment of malignant mesothelioma. As treatment options for malignant mesothelioma are limited and no cure is available, there is no established role for early detection or screening of at risk populations. A multidisciplinary approach to caring for patients with malignant mesothelioma and their carers is vital.

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.

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.

Comorbidity, postoperative morbidity and survival in patients undergoing radical surgery for malignant pleural mesothelioma

OBJECTIVES

We examined a series of malignant pleural mesothelioma (MPM) patients who underwent radical surgery to explore relationships among comorbidity, postoperative morbidity and survival.

METHODS

A retrospective analysis was carried out of all MPM patients operated on in a single centre from 2000 to 2015. The Charlson Comorbidity Index (CCI) was used to classify patients according to their underlying condition. Postoperative complications were scored according to WHO-derived criteria. Survival comparisons were performed by Cox analysis.

RESULTS

Ninety-one patients underwent extrapleural pneumonectomy (EPP), 47 underwent pleurectomy decortication (PD) and 25 underwent palliative pleurectomy. The mean CCI of PD patients was significantly higher compared with that of EPP patients (P= 0.044). The frequency of grade 3+ complications was similar between EPP and PD (27 vs 26%). However, EPP patients had a 6-fold higher frequency of pleural sepsis (24 vs 4%, P= 0.002) occurring up to 695 days postoperatively. Median overall survival was 19 months (95% CI 13-25) after EPP, 30 months (95% CI 20-35) after PD and 13 months (95% CI 5-32) after palliative pleurectomy. At multivariate analysis, CCI (P< 0.001), histology (P= 0.014) and pleural sepsis (P= 0.001), but not complete resection, were significantly associated with survival. There was a trend in favour of PD over palliative resection after adjusting for histology and CCI.

CONCLUSIONS

The CCI is an independent predictor of survival in MPM patients undergoing radical surgery. Owing to its significant frequency and adverse impact, pleural sepsis may contribute to a reduced life expectancy after EPP. Surgical treatment of MPM remains debatable.

Systemic Approach to Malignant Pleural Mesothelioma: What News of Chemotherapy, Targeted Agents and Immunotherapy?

Malignant pleural mesothelioma is a rare cancer with a cause-effect relationship to asbestos exposure. The prognosis is poor and chemotherapy seems the best treatment option. In the last two decades a deeper understanding of mesothelioma carcinogenesis and invasiveness mechanisms has prompted research efforts to test new agents in patients with malignant pleural mesothelioma, but the results have been modest. Attractive preclinical data disappointed in subsequent experimental phases. Other promising agents failed to improve patient outcomes due to high toxicity. Interesting suggestions have come from preliminary data on immunotherapy. Several trials are ongoing and the results are eagerly awaited. The aim of this review is to discuss the most recent news on systemic therapy for advanced malignant pleural mesothelioma.

Hemithoracic radiation therapy after extrapleural pneumonectomy for malignant pleural mesothelioma: Toxicity and outcomes at an Australian institution

INTRODUCTION

We aim to report the outcome of patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy (EPP) and adjuvant hemithoracic radiotherapy with or without chemotherapy at a single Australian institution.

METHOD

Between July 2004 and March 2013, 53 patients were referred for radiation treatment following EPP, of whom 49 were suitable for adjuvant treatment. Radiation treatment initially involved a 3D conformal, mixed electron/photon technique, delivering 45-50.4 Gy in 25-28 fractions (31 patients) and subsequently a nine-field intensity-modulated radiotherapy technique, delivering 50.4-54 Gy in 28-30 fractions (18 patients). Fifty-five per cent of patients also received pre-operative chemotherapy. We assessed toxicity, disease-specific and overall survival in patients who commenced radiation treatment.

RESULTS

Forty-one patients (84%) completed treatment as prescribed. Six patients stopped prematurely due to toxicity, and two with disease progression. Most patients discontinuing due to toxicity received over 90% of the prescribed dose. Common acute toxicities included nausea, fatigue, anorexia and dermatitis. Severe early toxicities were rare. Late toxicities were uncommon, with the exception of a persistent elevation in liver enzymes in those with right-sided disease. Neither clinical hepatitis nor radiation pneumonitis was documented. With a median follow up of 18.7 months, median disease-free and overall survival were 21.6 and 30.5 months, respectively, and 2-year overall survival was 57.3%.

CONCLUSION

Hemithoracic radiotherapy following EPP, although associated with significant early toxicity, is well tolerated. Most patients complete the prescribed treatment, and clinically significant late toxicities are rare.

An exception that proves the rule: recurrence free survival five years after extrapleural pneumonectomy for malignant pleural mesothelioma

Are case reports at all relevant and useful? A case report of an unusual case of mesothelioma prompts a discussion and concludes that they do have a role but that their observations and conclusions need to be treated with care.

Malignant pleural mesothelioma: current and future perspectives

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

Extrapleural pneumonectomy for malignant mesothelioma: an Italian multicenter retrospective study

BACKGROUND

This study assessed perioperative outcome and long-term survival in a large series of patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy (EPP) to identify prognostic factors allowing better patient selection.

METHODS

We retrospectively collected data from nine referral centers for thoracic surgery in Italy. Perioperative outcome and survival data were available for 518 malignant pleural mesothelioma patients (84.4% with epithelial tumors, 68.0% with pathologic stage 3 disease) who underwent EPP with intention-to-treat (R0/R1) between 2000 and 2010. Induction chemotherapy was administered in 271 patients (52.3%) and adjuvant therapy in 373 patients (72.0%), including radiotherapy in 213 patients (41.1%), adjuvant chemotherapy in 43 patients (8.3%), and both in 117 patients (22.6%).

RESULTS

In all, 136 patients (26.3%) had major complications after EPP, and 36 (6.9%) died within 90 days after surgery. The median overall survival was 18 months, with a 1-, 2-, and 3-year overall survival of 65%, 41%, and 27%, respectively. At multivariable analysis adjusted for age and disease stage, male sex (hazard ratio [HR] 1.47, 95% confidence interval [CI]: 1.12 to 1.92), nonepithelial histology (HR 1.96, 95% CI: 1.48 to 2.58), and trimodality treatment using induction chemotherapy (HR 0.61, 95% CI: 0.43 to 0.85) were significantly associated with survival. Development of a major complication also significantly worsened outcome (HR 1.85, 95% CI: 1.37 to 2.50).

CONCLUSIONS

The success of EPP in the context of a multimodality treatment depends on a series of patient characteristics. Female patients, patients with epithelial tumors, and patients who received induction chemotherapy will best benefit from EPP.

CD74: a new prognostic factor for patients with malignant pleural mesothelioma

Background:

The pro-inflammatory cytokine migration inhibitory factor (MIF) and its receptor CD74 have been proposed as possible therapeutic targets in several cancers. We studied the expression of MIF and CD74 together with calretinin in specimens of malignant pleural mesothelioma (MPM), correlating their expression levels with clinico-pathologic parameters, in particular overall survival (OS).

Methods:

Migration inhibitory factor, CD74, and calretinin immunoreactivity were investigated in a tissue microarray of 352 patients diagnosed with MPM. Protein expression intensities were semiquantitatively scored in the tumour cells and in the peritumoral stroma. Markers were matched with OS, age, gender, and histological subtype.

Results:

Clinical data from 135 patients were available. Tumour cell expressions of MIF and CD74 were observed in 95% and 98% of MPM specimens, respectively, with a homogenous distribution between the different histotypes. CD74 (P<0.001) but not MIF overexpression (P=0.231) emerged as an independent prognostic factor for prolonged OS. High expression of tumour cell calretinin correlated with the epithelioid histotype and was also predictive of longer OS (P<0.001). When compared with previously characterised putative epithelial-to-mesenchymal transition markers, CD74 correlated positively with tumoral PTEN and podoplanin expressions, but was inversely related with periostin expression.

Conclusions:

High expression of CD74 is an independent prognostic factor for prolonged OS in mesothelioma patients.

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.

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

BACKGROUND

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

CONCLUSION

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

The expression of Axl receptor tyrosine kinase influences the tumour phenotype and clinical outcome of patients with malignant pleural mesothelioma

BACKGROUND

Recent preclinical studies identified Axl, a tyrosine kinase receptor implicated in tumour progression and epithelial-to-mesenchymal transition, as a putative therapeutic target in malignant pleural mesothelioma (MPM), an invariably fatal malignancy with limited treatment options. Here, we studied the expression of Axl and its ligand Gas-6 (growth arrest signal-6) in primary specimens of MPM, correlating their expression levels with tumour phenotype and clinical outcomes.

METHODS

Two independent cohorts of consecutive patients diagnosed with MPM were studied: a derivation cohort composed of 63 cases and a validation set of 35 cases. Clinical variables including patients' demographics, tumour stage, histotype, performance status (PS), Axl and Gas-6 staining were tested for predicting overall survival (OS) using univariate and multivariate analyses.

RESULTS

In the derivation cohort, Axl (P=0.001) but not Gas-6 overexpression (P=0.35) emerged as a univariate prognostic factor for OS, together with stage (P=0.05), PS (P<0.001) hypoalbuminaemia (P<0.001) and anaemia (P<0.001). Multivariate analyses confirmed Axl overexpression (P=0.01), PS (P=0.01), hypoalbuminaemia (P<0.001) and anaemia (P=0.04) as independent predictors of OS. The prognostic role of Axl overexpression was externally validated in an independent cohort (P=0.03).

CONCLUSION

Overexpression of Axl is found in the majority of MPM specimens and influences patient's survival independently from other established prognostic factors. Such information may support patient selection for future trials.

Postmortem findings of malignant pleural mesothelioma: a two-center study of 318 patients

BACKGROUND

Malignant pleural mesothelioma (MPM) is an incurable cancer with a rising incidence. MPM is often perceived as a locally invasive cancer, and the exact cause of death is poorly understood.This two-center study describes the anatomic features of patients with MPM at postmortem.

METHODS

The Western Australia Mesothelioma Registry (Australia) and Coroner’s Office reports from the Avon region (England) were interrogated for the postmortem records of confirmed mesothelioma cases.

RESULTS

Postmortem records of 318 patients with pleural mesothelioma (169 from Western Australia and 149 from Avon) were identified. Most patients (91.5%) were men (mean age, 68.4 ± 11.5 years), and MPM was right-sided in 55.3%. Extrapleural dissemination of tumor was found in 87.7% of cases and lymph node involvement in 53.3%. Tumor dissemination in extra thoracicsites was common (55.4% of patients), and almost all organs were involved, including liver(31.9%), spleen (10.8%), thyroid (6.9%), and the brain (3.0%). Pulmonary emboli were found in 6% of cases and considered as directly contributing to death in 13 patients (4.1%). The precise cause of death could only be determined in 63 (19.8%) cases even after postmortem. The BMI was significantly lower in cases that had no identifiable anatomic cause of death at postmortem(18.8 ± 4.3 vs 21.0 ± 4.7, P = .034).

CONCLUSIONS

In this largest, to our knowledge, postmortem series on MPM, extrathoracic dissemination of mesothelioma was common and often under recognized. No anatomic cause of death was identified in the majority of patients even at autopsy, raising the possibility of physiologic and metabolic causes of death.

Outcome and prognostic factors of pleural mesothelioma after surgical diagnosis and/or pleurodesis

OBJECTIVE

The objective of this study was to evaluate long-term survival and prognostic factors in patients with malignant pleural mesothelioma.

METHODS

All consecutive patients referred for surgical diagnosis and/or pleurodesis for malignant pleural mesothelioma between 2000 and 2010 were studied. The following parameters were prospectively recorded: age, sex, tobacco consumption, asbestos exposure, type and duration of symptoms, American Society of Anesthesiologists (ASA) score, body mass index, preoperative C-reactive protein levels, white blood cells and platelet count, pachypleuritis on chest radiograph, type of diagnostic surgical procedure, histologic type, modality of pleurodesis, and chemotherapy. Survival was assessed on March 1, 2011.

RESULTS

A total of 170 patients were included. For the entire population, median survival was 12 months (95% confidence interval [CI], 10-15). Two-, 5-, and 7-year overall survival was 26% (95% CI, 19-35), 11% (95% CI, 6-21), and 5% (95% CI, 9-22), respectively. Asbestos exposure, age, ASA class III versus ASA classes I and II, nonepithelioid histology, C-reactive protein levels >3 mg/L, and white cell count >12,000/mm(3) influenced outcome in univariate analysis. Multivariate analysis showed that nonepithelioid histology (hazard ratio [HR], 2.76; 95% CI, 1.50-5.08); age (HR, 1.05; 95% CI, 1.01-1.08); C-reactive protein levels between 4 and 50 mg/L, and >51 (HR, 2.28; 95% CI, 1.18-4.42; and HR, 2.69; CI, 1.29-5.60, respectively); and leukocytosis >12,000/mm(3) (HR, 2.28; 95% CI, 1.22-4.25) were independent worse survival predictors.

CONCLUSIONS

Median survival in an unselected population of patients with malignant pleural mesothelioma treated nonsurgically is 12 months. Nonepithelioid histology, older age, abnormal C-reactive protein levels, and leukocytosis are independent predictors of worse survival.

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.

Malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumour that commonly affects the mesothelial surfaces of the pleural and peritoneal cavities, and occasionally, the tunica vaginalis and the pericardium. Formerly a rare tumour, MM is increasing in incidence in Australia due to the heavy nationwide use of asbestos from 1940 until the 1980s. The incidence is expected to peak in Australia in the next decade, mirroring the long latency period between asbestos exposure and development of MM. Diagnosis of MM can be difficult. Definitive pathological diagnosis is required and it often requires an experienced pathologist to differentiate MM from other benign or malignant processes. Treatment of MM requires a multidisciplinary approach, regardless of palliative or curative intent. Treatment options, such as surgery, chemotherapy, radiotherapy and active symptom control or a combination of these, may be used. Further research is needed to advance the therapeutic options for MM, and strategies to realize personalisation of therapy through discovery of predictive markers. In the Australian society where asbestos contamination of the built environment is very high, education and stringent public health measures are required to prevent a second wave of increased MM incidence.

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.

Audit of patients with mesothelioma treated with pemetrexed in a single institution in Western Australia

Malignant pleural mesothelioma (MPM) is a devastating malignancy that until recently has had no effective treatment. Pemetrexed in combination with cisplatin entered routine clinical practice following reports of efficacy in 2003. We performed a retrospective analysis of all patients with malignant mesothelioma at a single institution treated with pemetrexed in any combination or as monotherapy between 2004 and 2007. During this period, 62 patients received pemetrexed-based chemotherapy for MPM, most of whom were male (87%), treated in the palliative setting (84%) and received pemetrexed in combination with a platinum agent (95%). Pemetrexed was found to be well tolerated and produced clinical benefit and response rates similar to other published studies for its use in MPM in the phase IV or community practice settings. Patients with progressive disease as their best radiological response had very poor outcomes, while patients with stable disease had similar outcomes to those with responses. We confirmed that survival after commencement of pemetrexed-based chemotherapy remains under one year in this group of patients, somewhat less than the survival reported in phase III trials that currently inform clinical decision making. Further research is required to identify those patients who might benefit from pemetrexed based on molecular predictive markers.

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.

Surgical therapy of mesothelioma

The treatment of malignant pleural mesothelioma is controversial, particularly regarding the role of surgery. Though well accepted as a diagnostic modality, surgery is also frequently used to establish stage, provide palliation, and perhaps most controversially, to offer cytoreduction with the putative goal of delaying tumor progression and prolonging survival. Pleurectomy/decortication (PD) can achieve macroscopic complete resection; however, the ability to deliver effective postoperative radiation treatment is limited because of the risk of lung toxicity. Accordingly, it has been associated with higher rates of local recurrence compared to extrapleural pneumonectomy (EPP). Extrapleural pneumonectomy generally offers a more complete cytoreduction compared to PD but at the cost of increased morbidity and mortality. Adjuvant hemithoracic radiation is feasible following EPP and in most series local recurrence rates are lower after EPP than PD. There are no convincing data, however, to show that one procedure is superior to the other in terms of survival. Furthermore, no randomized data currently exist that demonstrate a survival benefit to any form of surgical cytoreduction over systemic treatment and supportive care. If cytoreductive surgery does have a beneficial effect on long-term survival, it will most likely be realized in patients with epithelioid tumors without nodal metastases.

Serum soluble mesothelin concentrations in malignant pleural mesothelioma: relationship to tumor volume, clinical stage and changes in tumor burden

PURPOSE

To examine the clinical utility of soluble mesothelin in patients with malignant pleural mesothelioma.

EXPERIMENTAL DESIGN

A total of 97 patients (female: 11; male: 86) were prospectively enrolled, longitudinal serum samples collected, and mesothelin concentrations determined. Baseline mesothelin levels were analyzed relative to tumor stage, presence of metastatic disease, the positron emission tomography (PET) parameters maximum standardized uptake value, tumor volume, total glycolytic volume, and survival. Changes in mesothelin level were correlated to objective response to chemotherapy, as assessed radiologically and by PET imaging, and with patient survival.

RESULTS

Baseline mesothelin levels greater than 5 nmol/L were a significant negative prognostic indicator (HR = 2.25; 95% CI, 1.20-4.21) and correlated with tumor stage and volume. In 55 patients who received chemotherapy, change in mesothelin correlated with radiological response (χ(2) = 11.32; P = 0.023) and change in metabolically active tumor volume (r = 0.58; P < 0.01). Median survival for patients with a reduction in mesothelin following chemotherapy (19 months) was significantly longer than for patients with increased mesothelin (5 months; P < 0.001).

CONCLUSION

These findings show the potential value of changes in mesothelin levels for prognostication and monitoring of treatment response in mesothelioma.

Surgical assessment of malignant pleural mesothelioma: have we reached a critical stage?

OBJECTIVE

The International Mesothelioma Interest Group (IMIG) classification is the most widely used staging system but is based on post-resectional parameters. We aimed to test the association between clinical and pathological staging and to identify possible discrepancies.

METHODS

We identified 164 consecutive patients (144 males and 20 females, with mean age 58 years) who underwent radical surgery (114 extrapleural pneumonectomy; 50 radical pleurectomy/decortication) for malignant pleural mesothelioma (MPM). The patients were clinically staged with CT + or - MRI (CT, computed tomography; MRI, magnetic resonance imaging).

RESULTS

Clinical T (cT) stage proved to be the same as pathological T (pT) stage in 44%; understaged in 46% and overstaged in 10%. Clinical N (cN) stage proved to be the same as pathological N (pN) stage in 56%; understaged in 31% and overstaged in 13%. Disease-free interval (DFI) was associated with cT stage (median DFI 29 months, SE 13, 95% CI 3-54 months for cT1; median 5, SE 3, 95% CI 3-6 months for cT4, p=0.02) but not clinical N stage (median DFI 12 months, SE 1, 95% CI 9-15 months for cN0; median DFI 11 months, SE 0.3, 95% CI 10-12 months for cN2, p=0.5) and was associated with both pT (median DFI 31 months, SE 17, 95% CI 0-64 months for pT1; median DFI 8 months, SE1, 95% CI 6-11 months for pT4, p=0.03) and pN stage (median DFI 14 months, SE 3, 95% CI 9-20 months for pN0; median DFI 10 months, SE 1, 95% CI 8-13 months for pN2, p=0.02). Overall survival was associated with cT stage (median survival 25 months, SE 3, 95% CI 20-30 months for cT1; median survival 11 months, SE 3, 95% CI 10-11 months for cT4, p=0.01) but not cN stage (median survival 15 months, SE 2, 95% CI 11-19 months for cN0; median survival 15 months, SE 2, 95% CI 12-19 months for cN2, p=0.49) and pN stage (median survival 22 months, SE 3, 95% CI 19-27 months for pN0; median survival 14 months, SE 1, 95% CI 12-17 months for pN2, p=0.01) but not pT stage (median survival 27 months, SE 4, 95% CI 19-35 months for pT1; median survival 12 months, SE 2, 95% CI 9-15 months for pT4, p=0.06). Pathological IMIG stage was associated with DFI and overall survival; however, preoperative IMIG stage was less useful.

CONCLUSIONS

There are deficiencies in the current staging system for MPM and discrepancies between clinical and pathological systems. Future improvements are needed in clinical descriptors of nodal status and pathological descriptors of T stage. Subsequent IMIG stage grouping also needs revision.