A review of chemotherapy trials for malignant mesothelioma

Diagnostic and Therapeutic Pathway in Diffuse Malignant Peritoneal Mesothelioma

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare form of mesothelioma that carries a very poor prognosis. The 5-year overall survival is about 20% (±5.9). Survival is optimal for patients suitable for cytoreductive surgery (CRS) with Hyperthermic Intraperitoneal Chemotherapy (HIPEC), with a median OS ranging from 34 to 92 months. However, selecting patients for surgery remains a complex task and requires a careful preoperative workup, rational analysis of prognostic profiles, and risk prediction models. Systemic chemotherapy could be offered: (1) in the adjuvant setting for high-risk patients; (2) for patients not eligible for CRS; and (3) for those with recurrent disease. It mainly includes the combination of Platin compound with Pemetrexed or immunotherapy. The biology of DMPM is still largely unknown. However, progress has been made on some fronts, such as telomere maintenance mechanisms, deregulation of apoptosis, tyrosine kinase pathways, and mutation of BRCA1-associated protein 1 (BAP1). Future perspectives should include translational research to improve our understanding of the disease biology to identify druggable targets. We should also clear the role of immune checkpoint inhibitors and investigate new locoregional technologies, such as pressurized intraperitoneal aerosol chemotherapy (PIPAC) or normothermic intraperitoneal chemotherapy (NIPEC).

Diffuse malignant peritoneal mesothelioma: A review

Diffuse malignant peritoneal mesothelioma (DMPM) is an unusual and life-threatening locally invasive tumor. The morbidity and mortality of the disease are associated with progressive local effects in the abdominal cavity, such as abdominal distention, painful sensations, and early saturation with reduced oral intake, which eventually lead to intestinal obstruction and cachexia. Computed tomography (CT) has been widely used as a first-line diagnostic tool for DMPM. In addition, the most sensitive immunohistochemical markers of DMPM include WT 1, D2-40, and calmodulin. This paradigm has altered with the advancements in the immunohistochemical analysis of BRCA1-Associated Protein 1 (BAP1) the lack of BAP1 expression shows the diagnosis of malignancy. DMPM is resistant to conventional chemotherapies. Therefore, the gold standard for the treatment of DMPM is the combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). The overexpression of the phosphatidylinositol 3-kinase (PI3K)/AKT serine/threonine kinase 1 (AKT)/mammalian target of rapamycin (mTOR) signaling pathway drives the malignant phenotype of DMPM, thereby showing promising potential for the treatment of DMPM. The coordinated activities among multiple RTKs are directly involved in the biological processes of DMPM, suggesting that the combined inhibition of the PI3K and mTOR signaling pathways might be an effective measure. This treatment strategy can be easily implemented in clinical practice. However, the combined inhibition of ERBB1(HER1)/ERBB2 (HER2) and ERBB3 (HER3) requires further investigations. Thus, based on these, the discovery of novel targeted therapies might be crucial to improving the prognosis of DMPM patients.

A new prognostic index for overall survival in malignant pleural mesothelioma: the rPHS (regimen, PS, histology or stage) index

OBJECTIVE

Existing prognostic indices for malignant pleural mesothelioma do not incorporate the recent advances in oncology care. The purpose of this study was to provide a prognostic index for overall survival in malignant pleural mesothelioma patients treated with chemotherapy with pemetrexed or best supportive care in the recent clinical setting.

METHODS

A retrospective cohort study was performed in two hospitals in Japan (2007-13). The primary outcome was overall survival. The Cox proportional hazards model was used for multivariable analyses to identify prognostic factors. A final model was chosen based on both clinical and statistical significance.

RESULTS

A total of 283 patients (chemotherapy: n = 228, best supportive care: n = 55) were enrolled in the study. On multivariate analysis, regimen including platinum plus pemetrexed, a performance status >0, non-epithelial histological type and Stage IV disease predicted poor overall survival in chemotherapy patients. As hazard ratios of individual risk factors were approximately similar, a prognostic index for overall survival was constructed by counting the risk factors. Median overall survival in chemotherapy patients decreased by each one-point increase in this count: 1030 days for zero; 658 days for one; 373 days for two; 327 days for three; 125 days for four. Internal validation using the bootstrapping technique showed robustness of the model (c-index, 0.677; 95% confidence interval, 0.624-0.729). Further, the discrimination was consistent in best supportive care patients (c-index, 0.799; 95% confidence interval, 0.725-0.874).

CONCLUSIONS

This novel index can provide clinicians and malignant pleural mesothelioma patients with a better framework for discussing prognosis at the time of diagnosis.

Bowman-Birk protease inhibitor from soybeans enhances cisplatin-induced cytotoxicity in human mesothelioma cells

Malignant mesothelioma (MM) is an aggressive cancer with no effective treatment options. Enforced expression of the gap junction (GJ) component connexin 43 (Cx43) increases the sensitivity of MM cells to cisplatin. Bowman-Birk protease inhibitor (BBI) induces the restoration of Cx43 in several types of tumor cells. In this study, we examined the capability of BBI to enhance the cytotoxic effect of cisplatin in MM cells via the induction of Cx43. Human MM H28 cells were used. Cell viability was evaluated by a WST-1 assay and proteasomal activity was determined by fluorometric analysis. Protein and mRNA levels were determined by immunoblot analysis and real-time RT-PCR, respectively. GJ function mediated by Cx43 was evaluated using the scrape-loading method. BBI effectively inhibited H28 cell growth in a dose-dependent manner (200-400 μg/ml). In parallel with the growth inhibition, Cx43 levels (mRNA and protein) and GJ function were elevated by BBI treatment. Knockdown of BBI-induced Cx43 by an antisense nucleotide treatment almost cancelled the growth inhibition. BBI enhanced cisplatin-induced cytotoxicity in H28 cells, and down-regulation of Cx43 by the antisense nucleotide treatment abrogated the enhancing effect of BBI. The induction of Cx43 by BBI contributed to Src inactivation and subsequent induction of Bax. Furthermore, an Src inhibitor (SU6656) also enhanced cisplatin-induced cytotoxicity in H28 cells. These results suggest that BBI improves the cytotoxic efficacy of cisplatin in H28 cells via the inhibition of Src signaling.

Targeted proteasome inhibition by Velcade induces apoptosis in human mesothelioma and breast cancer cell lines

INTRODUCTION

Thoracic malignancies and human breast cancer (HBC) continue to be aggressive solid tumors that are poor responders to the existing conventional standard chemotherapeutic approaches. Malignant pleural mesothelioma (MPM) is an asbestos-related tumor of the thoracic pleura that lacks effective treatment options. Altered ubiquitin proteasome pathway is frequently encountered in many malignancies including HBC and MPM and thus serves as an important target for therapeutic intervention strategies. Although proteasome inhibitor Velcade (Bortezomib) has been under clinical investigation for a number of cancers, limited preclinical studies with this agent have thus far been conducted in HBC and MPM malignancies.

PURPOSE

To study the biological and molecular responses of MPM and HBC cells to Velcade treatments, and to identify mechanisms involved in transducing growth inhibitory effects of this agent.

METHODS

Flow-cytometric analyses coupled with western immunoblotting and gene-array methodologies were utilized to determine mechanisms of Velcade-dependent growth suppression of five MPM (H2595, H2373, H2452, H2461, and H2714) and two breast cancer (MDA MB-468, SKBR-3) cell lines.

RESULTS

Our data revealed significant reduction in cell growth properties that were dose and time dependent. Velcade treatment resulted in G2M phase arrest, increased expression of cyclin-dependent kinase inhibitor p21 and pro-apoptotic protein Bax. Pretreatment of mesothelioma cells with Velcade showed synergistic effect with cisplatin combination regimens. High-throughput gene expression profiling among Velcade treated and untreated mesothelioma cell lines resulted in identification of novel transducers of apoptosis such as CARP-1, XAF1, and Troy proteins.

CONCLUSIONS

Velcade targets cell cycle and apoptosis signaling to suppress MPM and HBC growth in part by activating novel transducers of apoptosis. This pilot study has paved way for further in-depth analysis of the downstream target molecules associated with presensitization of mesothelioma cells in finding effective therapeutic treatment options for both mesothelioma and recalcitrant breast cancers.

Malignant pleural mesothelioma: medical treatment update

Malignant pleural mesothelioma (MPM) is a disease usually unaffected by current therapeutic strategies, but for the majority of patients, the use of systemic chemotherapeutic drugs remains the only therapeutic option available. During the past 15-20 years, many phase II and a few phase III clinical trials have studied a large variety of drugs such as anthracyclines, alkylating agents, platinum compounds, taxanes, vinka alkaloids, and antifolates as single agents and in combination, with the aim to increase responses and survival. The combination of pemetrexed and cisplatin tested in the largest phase III randomized trial of malignant pleural mesothelioma ever conducted has become the current standard of care. New targeted therapeutic approaches with a variety of anti-growth factor drugs are currently undergoing investigation worldwide.

Asbestos-related occupational lung diseases in NSW, Australia and potential exposure of the general population

Asbestos is a fibrous silicate which is recognized as causing a variety of lung disorders including malignant mesothelioma of the pleura, lung cancer and asbestosis. Asbestos use has been banned in most developed countries but exposure still occurs under strict regulation in occupational settings and also occasionally in domestic settings. Although the hazards of asbestos are well known in developed countries, awareness of its adverse health effects is less in other parts of the world, particularly when exposure occurs in non-occupational settings. Experience of asbestos use and its adverse heath effects in developed countries such as Australia have resulted in development of expertise in the diagnosis and treatment of asbestos-related diseases as well as in screening and this can be used to help developing countries facing the issue of asbestos exposure.

Soluble mesothelin-related protein in an asbestos-exposed population: the dust diseases board cohort study

RATIONALE

Soluble mesothelin-related protein (SMRP) is raised in epithelial-type malignant mesothelioma (MM), but the utility of SMRP in screening for MM is unknown.

OBJECTIVES

We aimed to evaluate SMRP in an asbestos-exposed cohort.

METHODS

A total of 538 subjects were studied. Those with elevated SMRP (> or =2.5 nM) underwent further investigation including positron emission tomography/computed tomography.

MEASUREMENTS AND MAIN RESULTS

Mean (+/-SD) SMRP in healthy subjects exposed to asbestos (n = 223) was 0.79 (+/-0.45) nM. Fifteen subjects had elevated SMRP, of whom one had lung cancer, which was successfully resected. Another with lung cancer was undetected by SMRP. No subjects were diagnosed with MM. Mean SMRP in healthy subjects was significantly lower than in subjects with pleural plaques alone (P < 0.01).

CONCLUSIONS

This is the first large-scale prospective study of SMRP for screening for malignancy in asbestos-exposed individuals. A high false-positive rate was observed. SMRP seems unlikely to prove useful in screening for MM.

Response to the methylation inhibitor dihydro-5-azacytidine in mesothelioma is not associated with methylation of p16INK4a: results of cancer and leukemia group B 159904

INTRODUCTION

The molecular mechanisms of oncogenesis in mesothelioma involve the loss of negative regulators of cell growth including p16INK4a. Absence of expression of the p16INK4a gene product is exhibited in virtually all mesothelioma tumors and cell lines examined to date. Loss of p16INK4a expression has also been frequently observed in more common neoplasms such as lung cancer as well. In a wide variety of these malignancies, including lung cancer, p16INK4a expression is known to be inactivated by hypermethylation of the first exon. This project (CALGB 159904) intended to test the hypothesis that in mesothelioma loss of p16INK4a via methylation would correlate with response to the cytidine analog and methylation inhibitor dihydro-5-azacytidine (DHAC).

METHODS

Using tissue samples from CALGB 8833 and 9031, two clinical studies which used DHAC based therapy in mesothelioma, this study tested the hypothesis that tumors possessing methylation of p16INK4a would have a better response and survival following DHAC treatment than their nonmethylated counterparts.

RESULTS

Methylation of p16INK4a was identified in 4 of the 20 specimens. Although there was a trend towards improved survival the result was not statistically significant.

CONCLUSIONS

There was no significant correlation between the presence of p16INK4a methylation and response to DHAC therapy or overall survival.

Active symptom control with or without chemotherapy in the treatment of patients with malignant pleural mesothelioma (MS01): a multicentre randomised trial

BACKGROUND

Malignant pleural mesothelioma is almost always fatal, and few treatment options are available. Although active symptom control (ASC) has been recommended for the management of this disease, no consensus exists for the role of chemotherapy. We investigated whether the addition of chemotherapy to ASC improved survival and quality of life.

METHODS

409 patients with malignant pleural mesothelioma, from 76 centres in the UK and two in Australia, were randomly assigned to ASC alone (treatment could include steroids, analgesic drugs, bronchodilators, palliative radiotherapy [n=136]); to ASC plus MVP (four cycles of mitomycin 6 mg/m2, vinblastine 6 mg/m2, and cisplatin 50 mg/m2 every 3 weeks [n=137]); or to ASC plus vinorelbine (one injection of vinorelbine 30 mg/m2 every week for 12 weeks [n=136]). Randomisation was done by minimisation, with stratification for WHO performance status, histology, and centre. Follow-up was every 3 weeks to 21 weeks after randomisation, and every 8 weeks thereafter. Because of slow accrual, the two chemotherapy groups were combined and compared with ASC alone for the primary outcome of overall survival. Analysis was by intention to treat. This study is registered, number ISRCTN54469112.

FINDINGS

At the time of analysis, 393 (96%) patients had died (ASC 132 [97%], ASC plus MVP 132 [96%], ASC plus vinorelbine 129 [95%]). Compared with ASC alone, we noted a small, non-significant survival benefit for ASC plus chemotherapy (hazard ratio [HR] 0.89 [95% CI 0.72-1.10]; p=0.29). Median survival was 7.6 months in the ASC alone group and 8.5 months in the ASC plus chemotherapy group. Exploratory analyses suggested a survival advantage for ASC plus vinorelbine compared with ASC alone (HR 0.80 [0.63-1.02]; p=0.08), with a median survival of 9.5 months. There was no evidence of a survival benefit with ASC plus MVP (HR 0.99 [0.78-1.27]; p=0.95). We observed no between-group differences in four predefined quality-of-life subscales (physical functioning, pain, dyspnoea, and global health status) at any of the assessments in the first 6 months.

INTERPRETATION

The addition of chemotherapy to ASC offers no significant benefits in terms of overall survival or quality of life. However, exploratory analyses suggested that vinorelbine merits further investigation.

Characterization of human mesothelioma cell lines as tumor models for suicide gene therapy

BACKGROUND

The median survival time of patients with malignant pleural mesothelioma (MPM) remains poor. Therefore, novel therapeutic options are in high demand, and well characterized model systems for in vitro/vivo screening have to be established.

MATERIAL AND METHODS

For this purpose, 3 MPM cell lines (H-Meso-1, MSTO211H, and NCI-H28) were characterized and tested for susceptibility to recombinant adeno-associated virus 2 (rAAV2)-based vectors which have the potential for a loco-regional application.

RESULTS

Using multiplex fluorescence in situ hybridization, several recurrent chromosomal aberrations were observed for each of the MPM cell lines. Tumorigenicity of H-Meso-1 and MSTO-211H cells was shown in an intraperitoneal NOD/SCID mouse model, whereas NCI-H28 cells did not yield any tumors. Although all 3 cell lines were readily susceptible to rAAV2 vectors, differences in susceptibility were observed (H-Meso-1 > NCI-H28 > MSTO-211H). Furthermore, the efficacy of a potential suicide gene therapy using an rAAV2 suicide vector-transduced MPM cell line was determined in a proof-of-feasibility in vivo experiment.

CONCLUSION

The characterized cell lines described here may serve as a model for in vitro and in vivo preclinical gene therapy for the treatment of MPM using rAAV2 suicide vectors.

A retrospective analysis of malignant pleural mesothelioma patients treated either with chemotherapy or best supportive care between 1990 and 2005 A single institution experience

The aim of this study was to investigate the efficacy and safety profile of chemotherapy (CT) compared to best supportive care (BSC) in patients with histopathologically confirmed diffuse malignant pleural mesothelioma (DMPM). A total of 161 patients between 1990 and 2004 treated either with CT (109 patients) or BSC (52 patients) depending on patients choice were evaluated in this analyses. Chemotherapy protocols included a combination of cisplatin, mitomycin C and recombinant interferon alpha 2a (CM-In), or cisplatin, mitomycin C and ifosfamide (CMI), or cisplatin and gemcitabine (CG). We found a significant difference in the median survivals of the patients with CT compared to BSC, 11.3 months versus 8.0. Objective response rate was 28/109 (25.7%) with 3.7% of complete response rate. Stable disease rate was 39/109 (35.8%). There was a significant difference between median survivals of patients with objective response (17 months) and median survivals of patients with progressive diseases (6 months) and also with stable diseases (16 months). There was a significant difference between the stable disease and the progressive disease. Stages 3 and 4 patients of epithelial cell type having received chemotherapy live longer than those not having received chemotherapy (12 months versus 4). There was no significant difference between the survivals of the different chemotherapy regimens. The toxicity with CT regimens were mild and well-tolerated. We conclude that CT prolongs survival compared to BSC in patients with DMPM. Survivals of patients with objective response prolong considerably with CT compared BSC. We observed that stages 3 and 4 patients with epithelial cell type got benefit from CT. Especially, of epithelial cell type stages 1 and 2 should receive multimodal treatment.

Radiotherapy for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma is a relatively uncommon disease, but the incidence is increasing and is expected to peak in many developed countries in the next two decades. The management of patients with malignant mesothelioma is controversial. Very few patients are suitable for any potentially curative treatment and the effectiveness of radical therapy with surgery, radiotherapy and/or chemotherapy in curing patients or prolonging survival is uncertain. The role of radiotherapy is controversial although it has been used as part of multimodal therapy. The present review will try to clarify these uncertainties.

OBJECTIVES

To assess the effectiveness and safety of radiotherapy on patients with malignant pleural mesothelioma in any stage of the disease.

SEARCH STRATEGY

Both electronic and handsearches were conducted. All randomised controlled clinical trials were searched in electronic databases such as: Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE. Handsearching was aimed at the identification of evidence by reviewing journals not indexed in databases, proceedings of conferences and/or scientific meetings.

SELECTION CRITERIA

All randomised controlled clinical trials using radiotherapy for malignant pleural mesothelioma in any stage, alone or combined with other therapies in patients of either sex and any age, were included. Studies without a control group were excluded.

DATA COLLECTION AND ANALYSIS

There were no studies that fulfilled the inclusion criteria.

MAIN RESULTS

To date we have not found any reports of randomised comparisons of radiotherapy alone or combined for patients with malignant pleural mesothelioma.

AUTHORS' CONCLUSIONS

As radiotherapy has never been compared to chemotherapy or surgery or to best supportive care (as part of combination therapy) in a prospective, randomised trial, no data exist supporting one or the other treatment as a better option for patients with malignant pleural mesothelioma. There is a need for multicentre controlled randomised trials assessing the role of radiotherapy in the radical treatment of malignant pleural mesothelioma. The studies should be limited to patients with malignant pleural mesothelioma, classified by stage, cytology and type of radiotherapy. The type of radiotherapy should be defined in advance and variables of radiotherapy dose definition and delivery should be carefully controlled.

Human neoplastic mesothelial cells express voltage-gated sodium channels involved in cell motility

Given the pivotal role of ion channels in neoplastic transformation, the aim of the present study has been to assess possible differences in the expression patterns of voltage-gated monovalent cationic (Na(+) and K(+)) currents between normal and neoplastic mesothelial cells (NM, MPM, respectively), and to evaluate the role of specific ion channels in mesothelioma cells proliferation, apoptosis, and motility. To achieve this aim, membrane currents expressed in NM and MPM cells derived from surgically-removed human specimens were investigated by means of patch-clamp electrophysiology. NM cells were found to express three main classes of K(+) currents, which were defined as K(IR), maxiK(Ca), and K(V) currents on the basis of their biophysical and pharmacological properties. Each of these K(+) currents was absent in MPM cells; by contrast, MPM cells revealed the novel appearance of tetrodotoxin (TTX)-sensitive voltage-gated Na(+) currents undetected in normal mesothelial cells. Reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR analysis of MPM cells transcripts showed significant expression of the mRNAs encoding for Na(V)1.2, and Na(V)1.6, and Na(V)1.7 (and less so for Na(V)1.3, Na(V)1.4, and Na(V)1.5) main voltage-gated sodium channel (VGSC) alpha-subunit(s). Interestingly, blockade of VGSCs with TTX decreased mesothelioma cell migration in in vitro motility assays; on the other hand, TTX failed to interfere with cell viability, proliferation, and apoptosis progression triggered by UV exposure. In summary, the results of the present study suggest that VGSCs expression in MPM cells may favor the increased motility of the neoplastic cells, a phenotypic feature often associated with the malignant phenotype.

A phase II study evaluating the cisplatin and epirubicin combination in patients with unresectable malignant pleural mesothelioma

Few chemotherapeutic agents have demonstrated their efficacy in malignant mesothelioma. The cisplatin plus doxorubicin combination has one of the highest response rates. Epirubicin is an anthracyclin, analogous to doxorubicin, with a different toxicologic pattern. As there are no data on the activity of the combination cisplatin plus epirubicin in malignant mesothelioma, the European Lung Cancer Working Party (ELCWP) designed a phase II study with response rate as primary objective. Sixty-nine eligible patients with malignant pleural mesothelioma were centrally registered. The majority of the patients were male (n=59), had a Karnofsky performance status of 80 or more (n=62) and presented with an epithelial histologic subtype (n=43). Median age was 62 years. In nine patients, metastases were documented at the initial work-up, mainly in bone, lung and skin. Three hundred and twenty-four cycles of chemotherapy were administered. The main toxicities were nausea and vomiting, neutropenia and alopecia. Among 63 assessable patients, response rate was 19.0% (95% confidence interval [CI] 9-29%). Median survival was 13.3 months. In multivariate analysis, poor prognostic factors for survival were neutrophil count and CALGB groups 4-6. In conclusion, cisplatin plus epirubicin appears as an effective regimen in malignant mesothelioma, with a favourable toxicity profile. However, it does not demonstrate superior activity to other active regimens in this disease.

Measuring quality of life in patients with pleural mesothelioma using a modified version of the Lung Cancer Symptom Scale (LCSS): psychometric properties of the LCSS-Meso

Health-related quality of life (QOL) assessment is a key component in patient assessment and the development of therapies for malignant pleural mesothelioma. However, no mesothelioma-specific instrument was available. The Lung Cancer Symptom Scale (LCSS), a site-specific instrument used to assess QOL in patients with lung cancer, was identified as an instrument that could be appropriate. A modified nine-item patient-reported and six-item observer-reported LCSS was incorporated into two clinical trials of pemetrexed in patients with pleural mesothelioma. Basic psychometric properties of feasibility, reliability, and validity were tested. Properties were stable or enhanced by deletion of the hemoptysis item. Feasibility was demonstrated with a high completion rate of 90% by 512 patients. Reliability was acceptable, with good internal consistency for the eight-item measure (alpha coefficient=0.86) and reasonably good for the five-item observer measure (alpha coefficient=0.66); there was also good stability for the patient measure using test-retest (r=0.87). Content validity was supported by a literature review and patient self-report of presenting symptoms (>90% of patients had three or more symptoms). Construct validity was well supported by finding better scores in the higher performance status groups and greater symptom improvement in patients with tumor response, good concordance with the LCSS conceptual model and good explanation of variance for summation items, and a high degree of convergence between the patient and observer forms (r=0.57). Criterion-related validity was supported by predicting survival time, time to progression, and tumor response rate; all three summary items and the total LCSS-Meso score were statistically significant predictors (p<0.005). The LCSS-Meso is a feasible, reliable, and valid instrument to assess health-related QOL in patients with pleural mesothelioma. One item, hemoptysis, was dropped from the original LCSS based on these findings.

Ifosfamide, mesna, and interferon-alpha2A combination chemoimmunotherapy in malignant mesothelioma: results of a single center in central anatolia

Our aim was to determine the efficacy of ifosfamide, mesna, and interferon alpha combination therapy in malignant mesothelioma (MM) patients. Fourty-two patients (39 evaluable) with histologically proven MM were enrolled into this study from January 1999 to October 2002. The drug schedule consisted of a combination of ifosfamide, 3000 mg/m2 1-3 d intravenous infusion (iv), the uroprotective agent mesna, 3000 mg/m2 1-3 d iv every 3 wk, and interferon alpha2a, 4.5 MU subcutaneously (sc) 3 d/wk for 6 mo as first-line chemotherapy. Overall, 140 cycles were administered to the 39 patients (median, 3.5 cycles; range, 1 to 6 cycles). Among the 39 patients, 8 partial remissions (PR) (21%) were observed. Thirteen patients (33%) had stable disease for at least 8 wk and 18 (46%) had progressive disease. Overall survival (OAS) and progression free survival (PFS) for all patients were 10.0 +/- 2.9 mo (95%CI 4.3-15.7) and 5.0 +/- 1.9 mo (95%CI 1.38-8.62), respectively. One and two year survival rates were calculated as 39% and 5%, respectively. All of the PR patients had the epithelial type of MM. Their survival time was 21.0 +/- 5.7 mo (95% CI 9.9-32.1) and significantly longer than that of nonresponders (p=0.0061). The toxicity of the drug combination was mild and well tolerated. There were no treatment-related deaths. Grade 3-4 neutropenia and febrile neutropenia were seen in 10 patients (26%) and 3 patients (8%), respectively. Chemotherapy was stopped in three patients because of renal function deficiency. One of these patients who had peritoneal MM required hemodialysis. In conclusion, this combination therapy showed encouraging antitumor activity with modest toxicity.

The palliative benefits of MVP (mitomycin C, vinblastine and cisplatin) chemotherapy in patients with malignant mesothelioma

BACKGROUND

With the rising incidence of malignant mesothelioma (MM), it is important to optimise treatment to control symptoms, maintain quality of life and, if possible, prolong life. We have analysed prospectively collected data to evaluate a frequently used palliative chemotherapy regimen.

PATIENTS AND METHODS

Between October 1986 and May 2002 all patients with inoperable pleural mesothelioma were considered for treatment with MVP (mitomycin C 8 mg/m2 every 6 weeks, vinblastine 6 mg/m2 every 3 weeks and cisplatin 50 mg/m2 every 3 weeks) chemotherapy. Symptoms were assessed by physician assessment at baseline and after each cycle of chemotherapy.

RESULTS

One hundred and fifty patients were treated with MVP for mesothelioma. Forty-three per cent had a performance status (PS) 2 or worse. The response rate was 15.3%, with 68.6% having stable disease. Sixty-nine per cent reported an improvement in symptoms; in particular there were good responses for pain (71%), cough (62%) and dyspnoea (50%). The most common grade 3/4 toxicity was neutropenia (22%). Median overall survival was 7 months, with 1-year survival 31% and 2-year survival 11%. Median survival for patients with PS 0/1 was 10 months, and was 6 months for patients with PS 2/3. Poor prognostic factors in univariate analysis included poor PS, weight loss, mixed or sarcomatoid histology, low haemoglobin and high white blood cell count. Excluding pathological subtype, the prognostic significance of poor PS and weight loss were retained in multivariate analysis.

CONCLUSIONS

Palliation of symptoms in MM is achievable with current cisplatin-based treatments.

Malignant pleural mesothelioma

Malignant pleural mesothelioma is an uncommon tumor; only about 3000 cases are diagnosed annually in the United States. Cases were described early in the 20th century, but their relationship to asbestos exposure was not documented until 1960. Since then, the incidence has appeared to increase, and numerous epidemiologic studies have confirmed that exposure to asbestos in a variety of settings and occupations is the most significant risk factor for the development of malignant pleural mesothelioma. More recently, the oncogenic virus SV40 has also been implicated as a potential etiologic agent. Surgery, radiotherapy, and chemotherapy have each been used in the treatment of mesothelioma, but generally with little impact on survival. New directions in therapy include aggressive multimodality programs for potentially resectable patients and targeted therapies, including antifolates, antiangiogenesis agents, and drugs directed at epidermal growth factor receptor for the majority of patients presenting with unresectable disease.

Measurement of mesothelioma on thoracic CT scans: a comparison of manual and computer-assisted techniques

Our purpose in this study was to evaluate the variability of manual mesothelioma tumor thickness measurements in computed tomography (CT) scans and to assess the relative performance of six computerized measurement algorithms. The CT scans of 22 patients with malignant pleural mesothelioma were collected. In each scan, an initial observer identified up to three sites in each of three CT sections at which tumor thickness measurements were to be made. At each site, five observers manually measured tumor thickness through a computer interface. Three observers repeated these measurements during three separate sessions. Inter- and intra-observer variability in the manual measurement of tumor thickness was assessed. Six automated measurement algorithms were developed based on the geometric relationship between a specified measurement site and the automatically extracted lung regions. Computer-generated measurements were compared with manual measurements. The tumor thickness measurements of different observers were highly correlated (r > or = 0.99); however, the 95% limits of agreement for relative inter-observer difference spanned a range of 30%. Tumor thickness measurements generated by the computer algorithms also correlated highly with the average of observer measurements (r > or = 0.93). We have developed computerized techniques for the measurement of mesothelioma tumor thickness in CT scans. These techniques achieved varying levels of agreement with measurements made by human observers.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments

This review summarises results of previously conducted clinical trials and subsequently presents data arising from all phase II-III studies on chemotherapy for malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear somewhat more promising. This applies especially to the antimetabolites, and in particular to pemetrexed which produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine--applied as a single agent or in combination with cisplatin--as well as vinorelbine appear to improve quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. Publication of results from a phase III trial of pemetrexed with cisplatin in a peer reviewed journal may soon establish a standard of care.

Mesothelial cell proliferation and apoptosis

Mesothelial cells line the pleural and peritoneal surfaces, where under normal conditions they proliferate and undergo cell death at a slow rate, thereby maintaining a constant number of cells. These tightly regulated processes are disrupted in malignancy. By developing a better understanding of the mechanisms that regulate cell proliferation and apoptosis in mesothelial and mesothelioma cells, we may be able to develop more effective therapeutic agents that target specific steps in these pathways to induce apoptosis more efficiently. This paper reviews our current knowledge of the signaling pathways involved in the regulation of mesothelial cell proliferation and apoptosis. The latest advancements in identifying proteins that play key roles in the resistance to apoptosis are highlighted.

The role of Alimta in the treatment of malignant pleural mesothelioma: an overview of preclinical and clinical trials

Malignant pleural mesothelioma (MPM) is a rare tumor, but its annual incidence is rapidly increasing. While most patients have locally advanced disease at presentation, to date there is no proven standard chemotherapy for MPM that has shown to increase survival in randomized studies. Therefore, the development of new therapeutic agents is urgent for this disease. Alimta is a novel, multitargeted antifolate with activity as single agent in patients with MPM. Recently, a phase III trial showed that the combination of Alimta with cisplatin resulted in a significantly increased efficacy compared with cisplatin alone. In addition, vitamin supplementation reduced treatment associated toxicities with no apparent affect on activity. This review summarizes preclinical and clinical data to define the future role of Alimta in the treatment of patients with MPM.

[Malignant mesothelioma--a diagnostic challenge]

Malignant mesothelioma is a rare neoplasm associated, in 80% of the cases, with exposure to asbestos fibres, with a latency period between 20 and 50 years. The treatment is palliative in most cases because of the extension of the disease at the time of diagnosis. Mesothelioma is a resistant tumour to chemotherapy and radiotherapy. Overall survival varies between 4 and 18 months, rarely over 5 years. The authors present a case of a 82-year-old man, ex-sailor, with prostatic neoplasm in hormonal "escape" phase, admitted with cough and dyspnea. The chest radiograph showed extensive right pleural effusion. The diagnostic hypothesis were metastatic, infectious and primitive neoplasm origin. Pleural biopsy revealed epithelial malignant mesothelioma confirmed by thoracoscopy, associated with prolongated occupational exposure to asbestos fibres. Without surgery indication the patient was submitted to chemotherapy with gencitabin and cisplatin associated with pleurodesis. Although he improved clinically, the presence of two malignant neoplasms, a rare situation in clinical practice, is associated with a poor prognosis, especially condicionated by the epithelial malignant mesothelioma in Butchart stage II. Finally, we discussed new differential diagnostic techniques with metastatic adenocarcinoma and target therapies under study.

BTS randomised feasibility study of active symptom control with or without chemotherapy in malignant pleural mesothelioma: ISRCTN 54469112

BACKGROUND

The incidence of mesothelioma is rising rapidly in the UK. There is no generally accepted standard treatment. The BTS recommends active symptom control (ASC). It is not known whether chemotherapy in addition prolongs survival or provides worthwhile palliation with acceptable toxicity. Palliation as recorded by patients has been fully reported for only two regimens: mitomycin, vinblastine, and cisplatin (MVP), and vinorelbine (N). The BTS and collaborators planned to conduct a phase III randomised trial comparing ASC only, ASC+MVP, and ASC+N in 840 patients with survival as the primary outcome measure. The aim of the present study was to assess the acceptability of the trial design to patients and the suitability of two standard quality of life (QL) questionnaires for mesothelioma.

METHODS

Collaborating centres registered all new patients with mesothelioma. Those eligible and giving informed consent completed EORTC QLQ-C30+LC13 and FACT-L QL questionnaires and were randomised between all three or any two of (1) ASC only, (2) ASC+4 cycles of MVP, and (3) ASC+12 weekly doses of N.

RESULTS

During 1 year, 242 patients were registered of whom 109 (45%) were randomised (55% of the 197 eligible patients). Fifty two patients from 20 centres were randomised to an option including ASC only. This translates into a rate of 312 per year from 60 centres interested in collaborating in the phase III trial. The EORTC QL questionnaire was superior to FACT-L in terms of completeness of data and patient preference. Clinically relevant palliation was achieved with ASC.

CONCLUSION

The planned phase III trial is feasible.

Factors influencing long-term survival in mesothelioma patients--results of the German mesothelioma register

Between 1987 and 2000, the German mesothelioma register recorded a total of 4,455 patients with malignant mesotheliomas. Survival times for 498 (11.2%) patients were available; 155 patients (study group, 3.5% of the total group) survived for more than 2 years and 343 patients (control group, 7.7% of the total group) survived for fewer than 24 months. Male patients were over-represented in both groups, with 13% of women in the study and 4.4% in the control group. The proportion of pleural mesotheliomas was more than 90% in both groups, with peritoneal cases comprising 6.5% in the study group and 3.2% in the control group. Histologically, the epithelioid subtype was represented in 58% of the study group, whereas the biphasic subtype predominated (67.6%) in the control group. Only 7% of tumours were of the sarcomatoid subtype. The average age of patients in the study group was 57.4 years, thus lower than in the control group (62.8 years). Lung dust analysis showed an increased pulmonary asbestos burden in 94% of all patients; significant differences between the study and control group were not observed. In the majority of the total group pleural effusions were the first symptoms. Therapeutic data were available in fewer than 40% of all cases. Surgical interventions were performed, partly in combination with radiation and chemotherapy and as alternative treatments. Significant deviations in survival time dependent on therapy applied could not be proved. By multivariate analysis (Cox proportional hazards regression model) favourable prognostic factors for long-term survival were epithelioid tumour subtype, comparatively young age (<60 years), and female gender ( P<0.05).

Preclinical evaluation of the nonsteroidal anti-inflammatory agent celecoxib on malignant mesothelioma chemoprevention

Malignant mesothelioma (MM) remains the most lethal pleural, peritoneal and pericardial cancer. Here, we characterize the effects of nonsteroidal anti-inflammatory agents (NSAIDs) on in vitro and in vivo experimental MM models. Unlike primary normal mesothelial cells, the selective cyclooxygenase (COX)-2 inhibitor celecoxib reduced the in vitro proliferation of several MM cells derived from previously untreated MM patients. Moreover, celecoxib significantly inhibited MM cell colony formation in soft agarose (63-78% at 5 x 10(-5) M; p < or = 0.05) and it elicited remarkable antitumor activity, leading to long-term survival in >37% of nude mice bearing intraperitoneal MM. Celecoxib was more efficient in inhibiting MM cell growth than acetylsalicylic acid (10(-6) M-10(-2) M), indometacin (10(-6) M-10(-2) M) and the COX-2 inhibitor NS-398 (10(-6) M-10(-4) M). Efficacy of these different compounds was not related to the amount of COX-2 protein levels present on MM cells. Celecoxib, in a dose- and time-dependent manner, induced MM cell apoptosis, which involved decreased Akt phosphorylation, loss of Bcl-2 and Survivin protein expression and caspase-3 activation. Furthermore, vascular endothelial growth factor (VEGF), an MM autocrine growth factor and Akt inducer, rescued celecoxib-induced apoptosis and Akt dephosphorylation. When the VEGF receptor (KDR/Flk-1) inhibitor, SU-1498, was used in combination with celecoxib, IC50 of celecoxib in vitro was reduced up to 65%. These data demonstrate that celecoxib may have antitumor properties in MM and provide a rationale for the therapeutic use of celecoxib in combination with a selective VEGF inhibitor.

Macrophage migration inhibitory factor and CXC chemokine expression in non-small cell lung cancer: role in angiogenesis and prognosis

PURPOSE

The purpose of this study was to determine whether expression of migration inhibitory factor (MIF) is increased in non-small cell lung cancer, and whether it correlates with angiogenesis and/or prognosis.

EXPERIMENTAL DESIGN

We measured vessel density, and levels of MIF, angiogenic CXC chemokines, and vascular-endothelial growth factor (VEGF; by ELISA) in tumor and normal lung tissue from 87 patients after resection of lung cancer. We compared vessel density with levels of MIF, VEGF, or angiogenic CXC chemokines in the corresponding tumor homogenate. Disease-free survival was analyzed in a Cox proportional hazards model.

RESULTS

Levels of MIF in lung cancer demonstrated a bimodal distribution, with some having "normal" values (relative to normal lung tissue) and a second cluster with markedly high values. The increased levels of MIF in lung cancer were statistically significant in both paired and unpaired comparisons (P < 0.05). The strongest correlation of vessel density was with the sum of angiogenic CXC chemokines. MIF correlated very strongly with levels of angiogenic CXC chemokines. Tumors in the high MIF group had a strong correlation between MIF level and vessel density. Risk of recurrence was associated with high levels of glutamic acid-leucine-arginine amino acid motif CXC chemokines, MIF, and/or VEGF in a Cox proportional hazards model.

CONCLUSIONS

MIF expression in non-small cell lung cancer occurs in a bimodal distribution, and is closely associated with tumor levels of angiogenic CXC chemokines and with vessel density. High levels of tumor-associated CXC chemokines, MIF, or VEGF are associated with risk of recurrence after resection of lung cancer.

Phase III study of pemetrexed in combination with cisplatin versus cisplatin alone in patients with malignant pleural mesothelioma

PURPOSE

Patients with malignant pleural mesothelioma, a rapidly progressing malignancy with a median survival time of 6 to 9 months, have previously responded poorly to chemotherapy. We conducted a phase III trial to determine whether treatment with pemetrexed and cisplatin results in survival time superior to that achieved with cisplatin alone.

PATIENTS AND METHODS

Chemotherapy-naive patients who were not eligible for curative surgery were randomly assigned to receive pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 on day 1, or cisplatin 75 mg/m2 on day 1. Both regimens were given intravenously every 21 days.

RESULTS

A total of 456 patients were assigned: 226 received pemetrexed and cisplatin, 222 received cisplatin alone, and eight never received therapy. Median survival time in the pemetrexed/cisplatin arm was 12.1 months versus 9.3 months in the control arm (P =.020, two-sided log-rank test). The hazard ratio for death of patients in the pemetrexed/cisplatin arm versus those in the control arm was 0.77. Median time to progression was significantly longer in the pemetrexed/cisplatin arm: 5.7 months versus 3.9 months (P =.001). Response rates were 41.3% in the pemetrexed/cisplatin arm versus 16.7% in the control arm (P <.0001). After 117 patients had enrolled, folic acid and vitamin B12 were added to reduce toxicity, resulting in a significant reduction in toxicities in the pemetrexed/cisplatin arm.

CONCLUSION

Treatment with pemetrexed plus cisplatin and vitamin supplementation resulted in superior survival time, time to progression, and response rates compared with treatment with cisplatin alone in patients with malignant pleural mesothelioma. Addition of folic acid and vitamin B12 significantly reduced toxicity without adversely affecting survival time.

Advances in the management of malignant mesothelioma

Malignant mesotheliomas are very aggressive tumors that originate from mesothelial cells, which form the serosal lining of the pleura, pericardial, and peritoneal cavities. Finding effective chemotherapeutic treatment for malignant mesothelioma is a challenge. There is no standard treatment because this tumor is relatively resistant to therapy. A resurgence of interest has been expressed in novel therapies and conventional treatments used in different ways. Several treatment modalities have been studied, including chemotherapy, radiotherapy, surgery, and immunotherapy. Chemotherapy can be administered systemically or directly into the pleura. This review presents the results of the most recent trials and highlights the most promising advances in the battle against this aggressive disease.

Diffuse malignant pleural mesothelioma: Part I. An overview of diagnosis, staging, and treatment options

Diffuse malignant mesothelioma is an uncommon, aggressive malignancy that occurs most often in the pleura of the lung. This article reviews the risk factors, incidence, signs, symptoms, diagnosis, staging, treatment options, and follow-up care of diffuse malignant pleural mesothelioma (DMPM). Curative approaches for treating DMPM are limited, and survival rates rarely exceed two years. Treatments such as surgery, chemotherapy, and radiotherapy have shown limited benefit in improving survival. Extrapleural pneumonectomy combined with multimodal treatments provides a potentially curative approach, and newer efforts in multimodality therapy are promising. Clinical trials utilizing intrapleural chemo-photodynamic, gene, and immunotherapies currently are under way.

The value of chest computer tomography and cervical mediastinoscopy in the preoperative assessment of patients with malignant pleural mesothelioma

BACKGROUND

Patients with localized malignant pleural mesothelioma (MPM) can be considered for surgical resection with or without additional treatment. For this approach it is imperative to select patients without mediastinal lymph node involvement. In this study cervical mediastinoscopy (CM) is compared with computer tomography (CT) scanning for its diagnostic accuracy in assessing mediastinal lymph nodes during preoperative workup.

METHODS

Computer tomography scans of the chest and CM were performed in 43 patients with proven unilateral MPM. The CT scans were reviewed by one radiologist and two chest physicians. At CM the lymph node samples were taken from stations Naruke 2, 3, 4, and 7. Computer tomography and CM results were compared with final histopathologic findings obtained at thoracotomy or, if this was not performed, at CM.

RESULTS

Computer tomography scanning revealed pathologic enlarged lymph nodes with a shortest diameter of at least 10 mm in 17 of 43 patients (39%). There was histopathologic evidence of lymph node metastases at CM in 11 of these patients (26%). This resulted in a sensitivity of 60% and 80%, a specificity of 71% and 100%, and a diagnostic accuracy of 67% and 93% for CT and CM, respectively.

CONCLUSIONS

Cervical mediastinoscopy is a valuable diagnostic procedure for patients with MPM who are considered candidates for surgical-based therapy. Results of CM are more reliable than those obtained by CT scanning. Our data confirm results of previous studies reporting that mediastinal lymph node involvement is a frequent event in MPM.