The effect of extent of local resection on patterns of disease progression in malignant pleural mesothelioma

Cytoreductive Surgical Treatment of Pleural Mesothelioma in a Porcine Model Using Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) and Radiofrequency Ablation (RFA)

A combination of surgery and chemotherapy is the most effective treatment available for Malignant Pleural Mesothelioma (MPM). However, both cause significant collateral damage and cannot eliminate residual microscopic disease. This investigation aimed to compare and determine the feasibility of utilizing Radiofrequency Ablation (RFA) and Magnetic-Resonance-guided Focused Ultrasound Surgery (MRgFUS) as alternative treatments for MPM. A large animal tumor model was developed in 13 Yorkshire female pigs using the MSTO211H cell line. Two pigs were initially used to determine the cyclosporine dose required for immunosuppression and tumor development. Subsequently, 11 other pigs underwent tumor development. Of these 11, 2 died during cell inoculation. Small tumor masses and adhesions were present in the other 9, indicating mesothelioma development. Five pigs then received RFA treatment, and 4 pigs received MRgFUS treatment. Tumor model development and effect of the two treatments were examined using MRI and by necropsy. RFA and MRgFUS both successfully ablated approximately the same sized area in the same treatment time. This study demonstrates that RFA and MRgFUS are feasible for tumor debulking, and while MRgFUS requires more pretreatment planning compared to RFA, MRgFUS is a completely noninvasive procedure.

Extrapleural pneumonectomies for pleural mesothelioma

Introduction: Malignant pleural mesothelioma (MPM) is a fatal malignancy for which there is no definitive cure. The most effective multimodality treatment in prolonging survival is still matter of debate. Surgery remains one of the cornerstones in the multimodality therapy for MPM. Extra-pleural pneumonectomy and pleurectomy/decortication are the two main curative-intent procedures; however, the superiority of one technique over the other is still debated. This review aims to assess short- and long-term results of extrapleural pneumonectomy for MPM.Areas covered: This article focuses on the role of extrapleural pneumonectomy in MPM. A systematic review was performed by using electronic databases to identify studies that included patients treated by this procedure for MPM. Endpoints included overall survival, disease-free survival, recurrence rate, perioperative mortality, and morbidity.Expert commentary: This paper offers an overview of the results that are currently obtained in patients undergoing extrapleural pneumonectomy for MPM. The benefit of surgical treatments in MPM is still debated and its primary goal should be the achievement of a macroscopic complete resection. Several alternative multimodality protocols exist, with specific advantages and drawbacks; therefore, individualization of care for each patient is fundamental. The complexity of the surgical treatment mandates that patients be referred to specialized centers.

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.

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.

Progress and challenges in Mesothelioma: From bench to bedside

Malignant Pleural Mesothelioma (MPM) is currently an incurable cancer with a typical survival of 1 year from the time of diagnosis. The recent genomic and transcriptomic characterization of MPM presents new opportunities and challenges for MPM researchers. Recent advances in clinical and laboratory diagnostics, and proposals for an updated, data-driven, staging system, also present new challenges for clinicians and hospital services involved in MPM care. The aim of this review is first to introduce the reader to the topic of MPM, a disease that is causally linked to prior, typically occupational, exposure to asbestos fibres. Secondly, we will discuss MPM from the clinical and laboratory perspectives, including reviews of current and evolving therapies and our present understanding of the molecular basis of the disease. Finally, we will attempt to identify critical knowledge gaps that currently prevent more effective treatment, including the challenges involved in early detection and chemoprophylaxis.

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.

The management of the diaphragm during radical surgery for malignant pleural mesothelioma

OBJECTIVES

Macroscopic complete resection with lung preservation is the objective of radical management of pleural mesothelioma (MPM). Total removal of visceral and parietal pleura (pleurectomy/decortication) almost invariably proceeds to an extended pleurectomy/decortication (EPD) to ensure macroscopic complete resection. We suspected this may not always be necessary.

METHODS

We reviewed 314 patients, 86.0% male, median age 62 years (range 14-81 years) undergoing radical surgery for MPM from 1999 to 2014, by either EPD or extrapleural pneumonectomy. The extent of diaphragmatic muscle involvement was recorded from postoperative pathology. Patients were divided into three groups: no involvement, non-transmural, transmural diaphragmatic invasion.

RESULTS

A total of 213 (68%) patients underwent EPD, 237 (75.5%) had epithelioid disease and 57.6% were node positive. There was no difference between the three groups in terms of age, cell type, laterality, neoadjuvant chemotherapy and operation. There was a higher degree of diaphragm involvement in females (P = 0.01) and in patients with positive lymph nodes (P = 0.01). No evidence of diaphragmatic involvement was found following pathological assessment of the resection specimen in 119 patients (37.9%). The incidence of abdominal disease progression was 23.9%. There was no correlation with degree of diaphragmatic invasion (ρ = 0.01 P = 0.88). Overall survival of those with abdominal progression was similar to those with progression elsewhere: 14.5 vs 13.0 months (P = 0.79), and with those with no progression (16.7 months, P = 0.189). There was no difference in survival when stratified by diaphragmatic involvement (P = 0.44).

CONCLUSIONS

In our cohort, there was no evidence of diaphragmatic invasion in over 30% of patients, and we have also failed to find evidence that peritoneal disease progression affects overall survival following radical management. It may therefore theoretically be unnecessary to resect the diaphragm in all cases, and a pleurectomy-decortication could suffice. However, there is an unknown risk of R2 resection which would prejudice survival, and as such we would advocate resecting the diaphragm in all cases to avoid an R2 resection.

Inhibition of NADPH oxidase 4 induces apoptosis in malignant mesothelioma: Role of reactive oxygen species

Malignant pleural mesothelioma (MPM) is an aggressive tumor that is characterized by dysregulated growth and resistance to apoptosis. Reactive oxygen species (ROS)-generating NADPH oxidase (Nox) family enzymes have been suggested to be involved in neoplastic proliferation. Both the antioxidant N-acetylcysteine (NAC) and the inhibitor of flavoprotein-dependent oxidase, diphenylene iodonium (DPI), inhibited the cell viability of MPM cells in a dose-dependent manner. To examine whether Nox-mediated ROS generation confers antiapoptotic activity and thus a growth advantage to MPM cells, we analyzed the mRNA expression of Nox family members using quantitative RT-PCR in 7 MPM cell lines and a normal mesothelial cell line. Nox4 mRNA was expressed in all of the examined MPM cell lines, whereas little or no Nox2, Nox3 and Nox5 mRNA expression was detected. In 2 MPM cell lines, Nox4 mRNA expression was significantly higher than that in a normal mesothelial cell line. siRNAs targeting Nox4 suppressed ROS generation and cell viability in the MPM cell lines. In addition, DPI treatment and knockdown of Nox4 attenuated phosphorylation of AKT and ERK. Taken together, our results indicate that Nox4-mediated ROS, at least in part, transmit cell survival signals and their depletion leads to apoptosis, thus highlighting the Nox4-ROS-AKT signaling pathway as a potential therapeutic target for MPM treatment.

Role of microRNAs in malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumor, mainly derived from the pleura, which is predominantly associated with exposure to asbestos fibers. The prognosis of MM patients is particularly severe, with a median survival of approximately 9-12 months and latency between exposure and diagnosis ranging from 20-50 years (median 30 years). Emerging evidence has demonstrated that tumor aggressiveness is associated with genome and gene expression abnormalities; therefore, several studies have recently focused on the role of microRNAs (miRNAs) in MM tumorigenesis. miRNAs are small non-protein coding single-stranded RNAs (17-22 nucleotides) involved in numerous cellular processes that negatively regulate gene expression by modulating the expression of downstream target genes. miRNAs are often deregulated in cancer; in particular, the differential miRNA expression profiles of MM cells compared to unaffected mesothelial cells have suggested potential roles of miRNAs as either oncogenes or tumor suppressor genes in MM oncogenesis. In this review, the mechanism of MM carcinogenesis was evaluated through the analysis of the published miRNA expression data. The roles of miRNAs as diagnostic biomarkers and prognostic factors for potential therapeutic strategies will be presented and discussed.

Pleural mesothelioma: an institutional experience of 66 cases

Background

Malignant mesothelioma of the pleura is an aggressive tumor known to be associated with asbestos. Histological diagnosis of mesothelioma is challenging and is usually aided by immunohistochemical markers.

Methods

During an 18-year period (1995-2012), 66 patients with pleural mesothelioma were diagnosed at the Samsung Medical Center in Seoul. We reviewed hematoxylin and eosin and immunohistochemical slides of pleural mesothelioma and evaluated their pathological and clinical features.

Results

The male-to-female ratio was 1.75:1, and age of patients ranged from 28 to 80 years with an average age of 56.84 years. Twenty-two out of 66 patients underwent curative pneumonectomy. Follow-up data was available in 60 patients (90.9%), and 50 of them (83.3%) died from the disease. The average overall survival was 15.39 months. Histologically, the epithelioid type was the most common, followed by the sarcomatoid and the biphasic types. Epidemiologic information was not available in most cases, and only one patient was confirmed to have a history of asbestos exposure.

Conclusions

Malignant mesothelioma of the pleura is a fatal tumor, and the therapeutic benefit of pneumonectomy remains unproven. The combination of calretinin, Wilms tumor 1, HMBE-1, and thyroid transcription factor-1 may provide high diagnostic accuracy in diagnosing mesothelioma.

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

PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Extra-pleural pneumonectomy versus no extra-pleural pneumonectomy for patients with malignant pleural mesothelioma: clinical outcomes of the Mesothelioma and Radical Surgery (MARS) randomised feasibility study

BACKGROUND

The effects of extra-pleural pneumonectomy (EPP) on survival and quality of life in patients with malignant pleural mesothelioma have, to our knowledge, not been assessed in a randomised trial. We aimed to assess the clinical outcomes of patients who were randomly assigned to EPP or no EPP in the context of trimodal therapy in the Mesothelioma and Radical Surgery (MARS) feasibility study.

METHODS

MARS was a multicentre randomised controlled trial in 12 UK hospitals. Patients aged 18 years or older who had pathologically confirmed mesothelioma and were deemed fit enough to undergo trimodal therapy were included. In a prerandomisation registration phase, all patients underwent induction platinum-based chemotherapy followed by clinical review. After further consent, patients were randomly assigned (1:1) to EPP followed by postoperative hemithorax irradiation or to no EPP. Randomisation was done centrally with computer-generated permuted blocks stratified by surgical centre. The main endpoints were feasibility of randomly assigning 50 patients in 1 year (results detailed in another report), proportion randomised who received treatment, proportion eligible (registered) who proceeded to randomisation, perioperative mortality, and quality of life. Patients and investigators were not masked to treatment allocation. This is the principal report of the MARS study; all patients have been recruited. Analyses were by intention to treat. This trial is registered, number ISRCTN95583524.

FINDINGS

Between Oct 1, 2005, and Nov 3, 2008, 112 patients were registered and 50 were subsequently randomly assigned: 24 to EPP and 26 to no EPP. The main reasons for not proceeding to randomisation were disease progression (33 patients), inoperability (five patients), and patient choice (19 patients). EPP was completed satisfactorily in 16 of 24 patients assigned to EPP; in five patients EPP was not started and in three patients it was abandoned. Two patients in the EPP group died within 30 days and a further patient died without leaving hospital. One patient in the no EPP group died perioperatively after receiving EPP off trial in a non-MARS centre. The hazard ratio [HR] for overall survival between the EPP and no EPP groups was 1·90 (95% CI 0·92-3·93; exact p=0·082), and after adjustment for sex, histological subtype, stage, and age at randomisation the HR was 2·75 (1·21-6·26; p=0·016). Median survival was 14·4 months (5·3-18·7) for the EPP group and 19·5 months (13·4 to time not yet reached) for the no EPP group. Of the 49 randomly assigned patients who consented to quality of life assessment (EPP n=23; no EPP n=26), 12 patients in the EPP group and 19 in the no EPP group completed the quality of life questionnaires. Although median quality of life scores were lower in the EPP group than the no EPP group, no significant differences between groups were reported in the quality of life analyses. There were ten serious adverse events reported in the EPP group and two in the no EPP group.

INTERPRETATION

In view of the high morbidity associated with EPP in this trial and in other non-randomised studies a larger study is not feasible. These data, although limited, suggest that radical surgery in the form of EPP within trimodal therapy offers no benefit and possibly harms patients.

FUNDING

Cancer Research UK (CRUK/04/003), the June Hancock Mesothelioma Research Fund, and Guy's and St Thomas' NHS Foundation Trust.

Expert opinions of the first italian consensus conference on the management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a very important public health issue. A large amount of data indicates a relationship between mesothelioma and asbestos exposure. The incidence has both considerably and constantly increased over the past 2 decades in the industrialized countries and is expected to peak in 2010-2020. In Italy, a standardized-rate incidence in 2002 among men was 2.98 per 100,000 and 0.98 per 100,000 among women, with wide differences from one region to another. Stage diagnosis and definition may be difficult. Management of patients with MPM remains complex, so an optimal treatment strategy has not yet been clearly defined. The First Italian Consensus Conference on Malignant Pleural Mesothelioma was held Bologna (Italy) in May 20, 2008. The Consensus Conference was given the patronage of the Italian scientific societies AIOM, AIRO, AIPO, SIC, SICO, SICT, SIAPEC-IAP, AIOT, GOAM, and GIME. This Consensus did not answer all of the unresolved questions in MPM management, but the Expert Opinions have nonetheless provided recommendations, presented in this report, on MPM management for clinicians and patients.

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.

Genetically engineered oncolytic Newcastle disease virus effectively induces sustained remission of malignant pleural mesothelioma

Malignant pleural mesothelioma is a highly aggressive tumor. Alternative treatment strategies such as oncolytic viral therapy may offer promising treatment options in the future. In this study, the oncolytic efficacy and induction of tumor remission by a genetically engineered Newcastle disease virus [NDV; NDV(F3aa)-GFP; GFP, green fluorescent protein] in malignant pleural mesothelioma is tested and monitored by bioluminescent tumor imaging. The efficacy of NDV(F3aa)-GFP was tested against several mesothelioma cell lines in vitro. Firefly luciferase-transduced MSTO-211H* orthotopic pleural mesothelioma tumor-bearing animals were treated with either single or multiple doses of NDV(F3aa)-GFP at different time points (days 1 and 10) after tumor implantation. Tumor burden was assessed by bioluminescence imaging. Mesothelioma cell lines exhibited dose-dependent susceptibility to NDV lysis in the following order of sensitivity: MSTO-211H > MSTO-211H* > H-2452 > VAMT > JMN. In vivo studies with MSTO-211H* cells showed complete response to viral therapy in 65% of the animals within 14 days after treatment initiation. Long-term survival in all of these animals was >50 days after tumor installation (control animals, <23 d). Multiple treatment compared with single treatment showed a significantly better response (P = 0.005). NDV seems to be an efficient viral oncolytic agent in the therapy of malignant pleural mesothelioma in an orthotopic pleural mesothelioma tumor model.

Second surgery for recurrence of malignant pleural mesothelioma after extrapleural pneumonectomy

BACKGROUND

Extrapleural pneumonectomy is a treatment option for malignant pleural mesothelioma (MPM), but disease recurrence is common. Among different therapeutic options for recurrence, we have found no reports for second surgical procedures.

METHODS

We retrospectively evaluated the types and outcomes of surgical management of solid recurrences of MPM, in a series of 74 patients treated with extrapleural pneumonectomy over a 20-year period.

RESULTS

Of 57 patients for whom follow-up data were available, 11 patients experienced recurrent disease in the form of a solid mass, 1.5 to 12 years after the initial treatment; 8 of these patients had sufficiently good clinical conditions to undergo a second surgery with curative intent. Chest wall resection was performed in 4 cases of parietal recurrence, radical retroperitoneal resection was done in 3 cases of retroperitoneal relapse, and segmental resection of the remaining lung was done in one case of pulmonary metastasis. In this latter case, although computed tomographic images showed a solid mass, at surgery the disease was found to have a serosal nature, precluding the possibility of a curative surgery. Median survival after the second surgery was 14.5 months (range, 6 to 29); no association between survival and site of recurrence, age or disease-free interval was found.

CONCLUSIONS

In this series, the second surgery did not offer the expected survival benefit of curative treatment strategies and should therefore be considered palliative. Second surgery may be a treatment option in a subset of patients who experience a solid recurrence of MPM that is symptomatic or near vital organs and who cannot undergo additional radiotherapy.

Multicenter phase II trial of neoadjuvant pemetrexed plus cisplatin followed by extrapleural pneumonectomy and radiation for malignant pleural mesothelioma

PURPOSE

Neoadjuvant pemetrexed plus cisplatin was administered, followed by extrapleural pneumonectomy (EPP) and hemithoracic radiation (RT), to assess the feasibility and efficacy of trimodality therapy in stage I to III malignant pleural mesothelioma.

PATIENTS AND METHODS

Requirements included stage T1-3 N0-2 disease, no prior surgical resection, adequate organ function (including predicted postoperative forced expiratory volume in 1 second > or = 35%), and performance status 0 to 1. Patients received pemetrexed 500 mg/m(2) plus cisplatin 75 mg/m(2) for four cycles. Patients without disease progression underwent EPP followed by RT (54 Gy). The primary end point was pathologic complete response (pCR) rate.

RESULTS

Seventy-seven patients received chemotherapy. All four cycles were administered to 83% of patients. The radiologic response rate was 32.5% (95% CI, 22.2 to 44.1). Fifty-seven patients proceeded to EPP, which was completed in 54 patients. Three pCRs were observed (5% of EPP). Forty of 44 patients completed irradiation. Median survival in the overall population was 16.8 months (95% CI, 13.6 to 23.2 months; censorship, 33.8%). Patients completing all therapy had a median survival of 29.1 months and a 2-year survival rate of 61.2%. Radiologic response of complete or partial response was associated with a median survival of 26.0 months compared with 13.9 months for patients with stable disease or progressive disease (P = .05).

CONCLUSION

This multicenter trial showed that trimodality therapy with neoadjuvant pemetrexed plus cisplatin is feasible with a reasonable long-term survival rate, particularly for patients who completed all therapy. Radiologic response to chemotherapy, but not sex, histology, disease stage, or nodal status, was associated with improved survival.

A phase II trial of tetrathiomolybdate after surgery for malignant mesothelioma: final results

BACKGROUND

Tetrathiomolybdate (TM) is an oral copper-depleting agent that has been shown to inhibit angiogenesis, and angiogenesis is a predictor of poor prognosis in malignant pleural mesothelioma. We hypothesized that cytoreduction of malignant pleural mesothelioma followed by TM will delay time to progression.

METHODS

Between November 2000 and August 2003, 30 patients with malignant pleural mesothelioma received postoperative TM beginning 4 to 6 weeks after surgery at a dose adjusted to keep ceruloplasmin between 5 and 15 mg/dL). Time to progression was compared with the 55 stage I and II patients and 109 stage III patients previously treated with cytoreduction by one of us (H.P.).

RESULTS

The 30 patients (25 men, 5 women; 13 stage I and II, 17 stage III), median age 67 years (range, 49-81 years), remained on TM a median of 14.9 months (range, 2 to 57 months). All patients reached target ceruloplasmin levels at a mean of 34 +/- 2 days (95% confidence interval, 30 to 39 days), and vascular endothelial growth factor levels at baseline (ceruloplasmin = 45.2 +/- 2 mg/dL) decreased from 2,086 +/- 390 pg/mL to 1,250 +/- 712 pg/mL (p < 0.002) at target ceruloplasmin (13 +/- 2 mg/dL; p < 0.0001 from baseline). The time to progression for all stage I or II TM patients was 20 months whereas that of 55 stage I or II non-TM-treated patients was 10 months (p = 0.046 versus TM). No differences in time to progression for the stage III TM patents from surgery were seen (7 months).

CONCLUSIONS

Tetrathiomolybdate has antiangiogenic effects in malignant pleural mesothelioma patients after resection of gross disease, and exhibits minimal toxicity and comparable efficacy to previous multimodality trials. Tetrathiomolybdate should be evaluated for efficacy in combination with standard malignant pleural mesothelioma regimens, as well as for postsurgical maintenance therapy.

Extrapleural pneumonectomy versus pleurectomy/decortication in the surgical management of malignant pleural mesothelioma: results in 663 patients

OBJECTIVE

The optimal procedure for resection of malignant pleural mesothelioma is controversial, partly because previous analyses include small numbers of patients. We performed a multi-institutional study to increase statistical power to detect significant differences in outcome between extrapleural pneumonectomy and pleurectomy/decortication.

METHODS

Patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy or pleurectomy/decortication at 3 institutions were identified. Survival and prognostic factors were analyzed by the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis.

RESULTS

From 1990 to 2006, 663 consecutive patients (538 men and 125 women) underwent resection. The median age was 63 years (range, 26-93 years). The operative mortality was 7% for extrapleural pneumonectomy (n = 27/385) and 4% for pleurectomy/decortication (n = 13/278). Significant survival differences were seen for American Joint Committee on Cancer stages 1 to 4 (P < .001), epithelioid versus non-epithelioid histology (P < .001), extrapleural pneumonectomy versus pleurectomy/decortication (P < .001), multimodality therapy versus surgery alone (P < .001), and gender (P < .001). Multivariate analysis demonstrated a hazard rate of 1.4 for extrapleural pneumonectomy (P < .001) controlling for stage, histology, gender, and multimodality therapy.

CONCLUSION

Patients who underwent pleurectomy/decortication had a better survival than those who underwent extrapleural pneumonectomy; however, the reasons are multifactorial and subject to selection bias. At present, the choice of resection should be tailored to the extent of disease, patient comorbidities, and type of multimodality therapy planned.

Outcomes after extrapleural pneumonectomy and intensity-modulated radiation therapy for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma is a locally aggressive tumor that is usually fatal. Extrapleural pneumonectomy (EPP) followed by hemithoracic irradiation has shown promise, but local failure remains a significant problem. To improve local control, we have used intensity-modulated radiation therapy (IMRT) as it allows better dose distribution to regions at risk of recurrence as well as reduced radiation to surrounding organs.

METHODS

One hundred consecutive patients underwent EPP. At a median interval of 2.5 months from surgery, 63 patients received IMRT (median dose 45 Gy) with curative intent. Chemotherapy was not routinely administered.

RESULTS

Tumors were right sided in 66 patients (66%) and nonepithelioid in 33 (33%). American Joint Committee on Cancer pathology stage was I in 6 patients (6%), II in 7 (7%), III in 72 (72%), and IV (T4) in 15 (15%). Fifty-four patients (54%) had ipsilateral nodal metastases. Perioperative mortality was 8%. Median overall survival (n = 100) was 10.2 months. For patients who received IMRT (n = 63), median overall and 3-year survival was 14.2 months and 20%. Of these, node-negative patients with epithelioid histology (n = 18) had median and 3-year survival of 28 months and 41%. Distant recurrences occurred in 33 of 61 evaluable patients (54%). Eight patients (13%) had local or regional recurrence, 5 of whom also recurred distally. Only 3 patients (5%) had recurrence within the irradiated field.

CONCLUSIONS

Intensity-modulated radiation therapy after EPP results in excellent local control for malignant pleural mesothelioma; however, distant metastases remain a significant problem and limit survival. This provides a strong rationale for combining aggressive local regimens with systemic therapy.

Management options for malignant pleural mesothelioma: clinical and cost considerations

Malignant pleural mesothelioma (MPM) is a resistant form of lung cancer that is often related to prior asbestos exposure. While surgical resection and radiotherapy techniques have been refined in recent years, neither has been proven to significantly extend patient survival compared with untreated controls. Until the release of pemetrexed in 2004, even combination chemotherapy regimens often resulted in a response rate of <20%. A recent phase III trial documented a 41.3% response rate for cisplatin plus pemetrexed. In the future, new multimodality regimens featuring novel targeted therapies directed against molecular targets, such as the vascular endothelial growth factor, hold the greatest promise for improved outcomes in MPM. The standard radiographic assessment of response to MPM therapy remains a poor surrogate for clinically relevant endpoints such as median survival. Furthermore, it is not currently known whether aggressive multimodality treatment for MPM will improve survival or quality of life above and beyond symptomatic care. Ongoing clinical trials are comparing chemotherapy and surgery with supportive care in an effort to define the role of different therapies in MPM. MPM treatment is a costly public health issue; after efficacy is proven, additional studies are needed to measure the cost effectiveness of MPM treatment regimens.

Emerging drugs for mesothelioma

Malignant mesothelioma is an aggressive, but relatively rare, malignancy, affecting the pleura and peritoneum. The prognosis for malignant pleural mesothelioma (MPM) is poor, with median survival in the range of 8-14 months, depending on stage and presentation of disease. Long-term results of available treatments are disappointing not only in terms of prognosis, but also of local control of the disease. Therefore, relief of symptoms and improvement of quality of life parameters are the short-term goals of therapy. In advanced disease not amenable to any local approach, such as surgery, combination chemotherapy represents the current standard of care. At present, the regimen of cisplatin/pemetrexed is the medical treatment of choice. This review summarizes standard chemotherapy options and focuses on the molecular basis of the newest biologically targeted therapies to be implemented in the near future, in the management of MPM.

Malignant pleural mesothelioma: a comprehensive review

BACKGROUND

The incidence of malignant mesothelioma continues to increase, but the disease remains difficult to detect early and treat effectively.

METHODS

The authors review the pathogenesis, incidence, clinical presentation, diagnosis, pathology, and both standard and experimental treatments for mesothelioma.

RESULTS

When possible, surgery (video-assisted thoracoscopy, pleurectomy/decortication, or extrapleural pneumonectomy) is utilized. Effects on underlying structures limit application of radiation therapy, but some systemic agents are beginning to enhance survival.

CONCLUSIONS

The disease is expected to increase in incidence till 2020, so awareness of this entity as a possible diagnosis should be heightened. In patients with advanced disease, several newer antitumor agents are already showing a capability of extending survival so it is not unreasonable to expect further progress in this area.

Radiotherapy for mesothelioma

Three to four thousand cases of malignant pleural mesothelioma will occur in the United States this year. Single-modality therapy with radiation plays a role for palliation. Radiation can prevent tumor recurrence at drain/instrumentation sites and provide symptomatic relief of pain and other complaints. Combinations of surgery and radiation also have been attempted with curative intent. The best local control has been found--EPP followed by radiotherapy. Locoregional tumor recurrence can be dramatically reduced with combinations of extrapleural pneumonectomy and radiation therapy. Survival in aggressively treated early-stage patients is excellent. However, the preponderance of death from distant metastases makes the development of better systemic therapy essential. Better therapy also must be developed for patients who are not candidates for extrapleural pneumonectomy.

Malignant mesothelioma

Malignant mesothelioma is an aggressive, treatment-resistant tumour, which is increasing in frequency throughout the world. Although the main risk factor is asbestos exposure, a virus, simian virus 40 (SV40), could have a role. Mesothelioma has an unusual molecular pathology with loss of tumour suppressor genes being the predominant pattern of lesions, especially the P16INK4A, and P14ARF, and NF2 genes, rather than the more common p53 and Rb tumour suppressor genes. Cytopathology of mesothelioma effusions or fine-needle aspirations are often sufficient to establish a diagnosis, but histopathology is also often required. Patients typically present with breathlessness and chest pain with pleural effusions. Median survival is now 12 months from diagnosis. Palliative chemotherapy is beneficial for mesothelioma patients with high performance status. The role of aggressive surgery remains controversial and growth factor receptor blockade is still unproven. Gene therapy and immunotherapy are used on an experimental basis only. Patterns identified from microarray studies could be useful for diagnosis as well as prognostication.

Hemithoracic radiation therapy after pleurectomy/decortication for malignant pleural mesothelioma

PURPOSE

To evaluate pleurectomy/decortication (P/D) and adjuvant radiotherapy (RT) in the treatment of malignant pleural mesothelioma (MPM).

METHODS AND MATERIALS

In a retrospective review, we included MPM patients treated with P/D and adjuvant RT at Memorial Sloan-Kettering Cancer Center from 1974 to 2003. When indicated, patients received intraoperative brachytherapy to residual tumor.

RESULTS

All 123 patients received external beam RT (median dose, 42.5 Gy; range, 7.2-67.8 Gy) to the ipsilateral hemithorax postoperatively. Fifty-four patients underwent brachytherapy (matched peripheral dose, 160 Gy). The median and 2-year overall survival for all patients was 13.5 months (range, 1-199 months) and 23%, respectively. One-year actuarial local control for all patients was 42%. Multivariate analysis for overall survival revealed radiation dose <40 Gy (p = 0.001), nonepithelioid histology (p = 0.002), left-sided disease (p = 0.01), and the use of an implant (p = 0.02) to be unfavorable. Two patients (1.6%) died from Grade 5 toxicity within 1 month of treatment.

CONCLUSIONS

Pleurectomy/decortication with adjuvant radiotherapy is not an effective treatment option for patients with MPM. Our results imply that residual disease cannot be eradicated with external RT with or without brachytherapy and that a more extensive surgery followed by external RT might be required to improve local control and overall survival.

Pleural mesothelioma: little evidence, still time to do trials

CONTEXT

The incidence of malignant pleural mesothelioma is increasing throughout most of the world. This cancer is uniformly fatal, and characterised by progressive breathlessness and unremitting pain in the chest wall. From the onset of symptoms, survival is from a few weeks to a few years. Desperation by patients and doctors has driven a search for effective treatments. Clinical benefits are marginal and evidence of a good quality is lamentably lacking.

STARTING POINT

David Sugarbaker is the world's leading proponent of extrapleural pneumonectomy (EPP), an operation in which all the pleura is removed with the lung, pericardium, and diaphragm. He has recently reported the complications of this radical surgery in a series of 496 operations (J Thorac Cardiovasc Surg 2004; 128: 138-46). Although EPP as part of trimodality therapy (preoperative chemotherapy and postoperative radiation) is thought to be the best that can be offered and is regarded as the standard of care for selected patients given the morbidity associated with it, evidence for benefit is needed to justify its wider use. WHERE NEXT? With the increase in the number of cases there is increasing awareness of the disease, leading to earlier diagnosis, and an expectation that something must be done. Survival is short and the treatments on offer are onerous. The only responsible approach from a scientific, compassionate, or economic view (and why not combine all three?) is to find evidence of effectiveness to avoid futile and distressing treatment when possible.