Guidelines of the European Respiratory Society and the European Society of Thoracic Surgeons for the management of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare tumour but with increasing incidence and a poor prognosis. In 2008, the European Respiratory Society/European Society of Thoracic Surgeons Task Force brought together experts to propose practical and up-to-dated guidelines on the management of MPM. To obtain an earlier and reliable diagnosis of MPM, the experts recommend performing thoracoscopy, except in cases of pre-operative contraindication or pleural symphysis. The standard staining procedures are insufficient in approximately 10% of cases. Therefore, we propose using specific immunohistochemistry markers on pleural biopsies. In the absence of a uniform, robust and validated staging system, we advice use of the most recent TNM based classification, and propose a three step pre-treatment assessment. Patient's performance status and histological subtype are currently the only prognostic factors of clinical importance in the management of MPM. Other potential parameters should be recorded at baseline and reported in clinical trials. MPM exhibits a high resistance to chemotherapy and only a few patients are candidates for radical surgery. New therapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach should be included in a prospective trial at a specialised centre.

Taurolidine and oxidative stress: a rationale for local treatment of mesothelioma.

Malignant mesothelioma is an asbestos-related, aggressive tumour, resistant to most anticancer therapies. Akt is a key mediator of mesothelioma cell survival and chemoresistance. This study aimed to clarify the mechanism by which taurolidine (TN), a known synthetic compound with antimicrobial and antineoplastic properties, leads to mesothelioma cell death. Apoptosis was studied by annexin V binding, cell cycle analysis, caspase-8 activation, poly(ADP-ribose) polymerase (PARP) cleavage and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL). Oxidative stress was measured by nitrite production and DNA oxidative damage. Protein expression and phosphorylation were evaluated by immunoprecipitation and immunoblotting. TN induces cell death of mesothelioma cells, but not of non-neoplastic human mesothelial cells. After TN treatment of mesothelioma cells, Akt but not extracellular signal-regulated kinase (Erk) 1/2 activity is inhibited a in time- and dose-dependent manner. Protein phosphatase (PP)1alpha and PP2A are activated several hours after drug addition. Apoptosis induced by TN is driven by oxidative stress and cell exposure to sulfydryl donors, such as glutathione monoethylester and l-N-acetylcysteine, significantly reduced pro-apoptotic effects and Akt inhibition. Conversely, expression of constitutively activated Akt did not affect cytoxicity elicited by TN, which retained its ability to inhibit the kinase. TN induces mesothelioma cell death via oxidative stress, accompanied by inhibition of Akt signalling. This provides a promising molecular rationale for TN as local treatment of malignant mesothelioma.

[Evaluation of a series of serum mesothelin in patients with pleural malignant mesothelioma]. / Valutazione di dosaggi seriati di mesotelina sierica in pazienti affetti da mesotelioma maligno della pleura.

Pleural Malignant Mesothelioma (MM) is a highly aggressive neoplasm with a poor survival rate, hard diagnosis and treatment. The incidence of MM in Western Europe countries is expected to increase drammatically in the next 10-15 years. In spite of this drammatic scenario, at this time the only instruments for screening and early diagnosis are based on radiological tests with evident ethical and economical problems. For this reason, some authors are evaluating biological indicators with the significance of screening and early diagnosis markers. One of the most promising marker is serum mesothelin (SMRP). SMRP levels appeares to be significantly related to MM and its clinical (diagnostic/prognostic) usefulnes has been suggested. The purpose of this research is to show SMRP trend in relation both to the course of the disease and the response to therapies in some Epithelioid MM patients. The analysis of SMRP levels in these patients suggests that it may be a useful marker for monitoring the response to treatment. In fact, it was observed that SMRP increases in patients who did not respond to therapy, it tends to remain stable when therapies results into a clinical stabilization, while it decreases after surgical procedure and in case of clinical improvement.

[Serum mesothelin dosages in follow-up of previously exposed workers]. / Il dosaggio della mesotelina sierica nel follow-up dei lavoratori ex esposti ad amianto.

High dosages of Serum Mesothelin have been demonstrated to be significantly associated to Pleural Malignant Mesothelioma. We recently demonstrated that Serum Mesothelin may be clinically helpful both for diagnostic and prognostic purposes, with the best cut-off corresponding to 1 nM. We also discovered that high levels of Serum Mesothelin are significantly associated to Lung Cancer. The usefulness of this marker in secondary prevention has been suggested, though never demonstrated. We therefore started a long-term prospective cohort study including previously asbestos-exposed workers. These subjects periodically underwent both radiological tests and serum mesothelin dosages. As a mid-term goal of this longitudinal study we decided to check the variability of mesothelin dosages, comparing baseline and follow-up values, as well as the possible correlation with age, duration of exposure, smoking, any abnormality of respiratory functional tests (RFT) and/or radiological tests. At baseline, Mesothelin mean value was 0.66 +/- 0.4 (range 0.08-2.2 nM). Both age (p = 0.04) and abnormal thoracic TC (p = 0.04) were significantly correlated with increased serum mesothelin levels and increasing age. No association was found between baseline mesothelin levels and duration of asbestos exposure (p = 0.5), smoking habits (p = 0.2), abnormal RFT, DLCO (carbon monoxide diffusing capacity) or thoracic X-ray. No significant variation was observed between mesothelin values at baseline and at follow-up (p = 0.2).

In vivo effect of human granulocyte-macrophage colony-stimulating factor (GM-CSF) on neutrophil GM-CSF receptors.

The effect of in vivo administration of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on neutrophils GM-CSF receptor, was investigated in patients with neoplastic diseases and normal hematopoiesis. Patients were divided into two groups. Group A received a single dose of rhGM-CSF (5 micrograms/kg/day) and receptor studies were performed 90 min and 48 h after treatment. Group B received three doses, administered subcutaneously every 24 h and receptor studies were performed 90 min after first injection and 24 h after the last. Before treatment neutrophils only displayed high-affinity receptors (KD 85 +/- 53 pM; number of receptors/cell 1318 +/- 567). The first injection of rhGM-CSF produced a transient leucopenia and the internalization of GM-CSF receptor on neutrophils in both groups of patients: 90 min after s.c. administration receptors could not be detected with conventional binding studies. In group A patients, 48 h after a single dose of rhGM-CSF, receptors, albeit with a decreased affinity (KD = 240 +/- 131 pM; number of receptors/cell 783 +/- 494) were again expressed. In group B patients, 24 h after the last rhGM-CSF injection, low intermediate affinity receptors not present before treatment appeared (KD 720 +/- 175 pM; number of receptor/cell 1222 +/- 179). They were associated with a low number of high affinity receptors (KD = 9 +/- 4 pM; number of receptors/cell 106 +/- 44). These observations indicate that more than one type of GM-CSF receptor may exist on neutrophils. It may be suggested that in vivo the regulation of the GM-CSF receptor is different from that in vitro and is related to the presence of the cytokine in patient blood.

Malignant mesothelioma in 2004: How advanced technology and new drugs are changing the perspectives of mesothelioma patients. Highlights from the VIIth Meeting of the International Mesothelioma Interest Group.

Malignant mesothelioma (MMe) is a seemingly uncommon tumour whose incidence has in fact increased steadily and progressively over the last 30 years. Indeed, an actual "epidemic" is expected in the next 20 years, with over 1300 new cases a year till 2020 at least. Despite unquestionable improvement in the diagnostic methods at our disposal and the availability of new treatment strategies, the prognosis of MMe patients remains dramatically poor. For all the above reasons, translational research is the key to success; indeed, ever increasing knowledge of the molecular mechanisms underlying MMe pathogenesis could lead (and is actually leading) to new, hopefully more active, treatment options. To foster discussion among investigators working in this field, and to exchange different viewpoints concerning the newest advances in MMe pathogenesis and treatment, the VII International Mesothelioma Interest Group (IMIG) meeting was held in Brescia (Italy) between 24 and 26 June 2004 in cooperation with the Italian Group for the Study and Therapy of MMe (GIMe). The aim of this report is to summarize the most significant advances in the different disciplines applied to MMe presented and discussed during the IMIG meeting and how these advances will be changing the perspective of patients with MMe.

Tnp-alpha determination in serum and pleural effusion in patients with lung-cancer.

The relationship between Tumor Necrosis Factor-alpha (TNF-alpha) in the serum and pleural fluid of lung cancer patients and the extent and the histological cell type was studied. TNF-(a)lpha level was determined in the serum of 68 patients with lung cancer [51 non-small cell lung cancer (NSCLC) and 17 small cell lung cancer (SCLC)] and in pleural fluid of 30 patients with lung cancer (22 NSCLC, 11 of them positive for neoplastic cells and 8 SCLC, 7 of them positive). Sera of 31 healthy subjects and the pleural fluid of 15 non-malignant pleural effusions were tested as controls. TNF-alpha serum level was increased in patients with lung cancer (healthy subjects 7.8+/-3.3 pg/ml; lung cancer 16.2+/-9.1 pg/ml), in NSCLC as well as SCLC and a relationship with the extent of the disease was found in both the histological types. In pleural fluid, no differences of TNF-alpha level were observed between neoplastic and benign inflammatory effusion, between SCLC and NSCLC or between cases positive and negative for the presence of neoplastic cells. Serum TNF-alpha may be an indicator of tumour burden; conversely, TNF-alpha in pleural fluid, was unable to discriminate between neoplastic and benign effusion.

Basic fibroblast growth factor in mesothelioma pleural effusions: correlation with patient survival and angiogenesis.

The expression of angiogenic factors may represent useful markers for diagnosis and prediction of disease outcome. Basic fibroblast growth factor (b-FGF) is a potent angiogenic factor which promotes in vitro growth of endothelial cells and in vivo vessel formation. We investigated the expression of b-FGF in patients affected with malignant and non-malignant pleural diseases and presenting clinically with non-specific signs and symptoms. We also studied the relationships between the expression of b-FGF in patients with malignant pleural mesothelioma (MM) and tumour aggressiveness, assessed as tumour vessel density (TVD), or patient survival. Basic-FGF was measured by immunoassay in the serum and pleural effusions (PE) of 37 patients. Of these, MM was diagnosed in 15/37 patients while the remaining patients had either peripheral lung adenocarcinoma (PLA) or benign inflammatory pleural disease (BPD). The mean b-FGF level measured 8.5+/-6.1 pg/ml in the PE of the malignant group (MM + PLA) and 23.9+/-19.8 in the PE of the non-malignant group (BPD) (p=0.001). The mean b-FGF level was significantly lower in the PE of MM patients (6.9+/-5.2 pg/ml) compared to BPD patients (p=0.004). Linear regression analysis showed a significant inverse correlation (r=-0.59; p=0.041) between b-FGF levels found in MM PE and patient survival. A noteworthy relationship between high serum b-FGF levels and reduced survival was also observed (r=-0.57; p=0.052). Interestingly, both serum (r=0.48; p=0.114) and PE (r=0.26; p=0.413) b-FGF levels in MM patients correlated poorly with TVD. Our data indicate that b-FGF is significantly more expressed in non-malignant compared to malignant PE, this difference being particularly evident between MM and BPD. Our results also suggest that high b-FGF levels correlate with poor MM patient survival through mechanisms which may be independent of b-FGF angiogenic potential.

Prognostic significance of presence and reduplication of basal lamina in malignant pleural mesothelioma.

The prognosis of patients with malignant pleural mesothelioma (MM) is dependent more on tumor extension and differentiation than on therapeutic effects. Reduplication of the basal lamina (RBL) is an ultrastructural feature of some benign and malignant tumors that has been inversely correlated with aggressiveness and was recently described in MM. To investigate whether RBL is important for predicting the survival of patients with MM, transmission electron microscopy was used to identify the presence of basal lamina or RBL in biopsy specimens obtained by thoracoscopy from 35 patients. Cox's regression analysis was used to study the relation of these ultrastructural features to survival. Better outcomes were found for patients whose tumors expressed either basal lamina (HR 0.48; 95% CI, 0.09-2.47) or RBL (HR 0.38; 95% CI 0.12-1.22) compared with the reference category, where basal lamina or RBL was not found. The expression of basal lamina and RBL is an important novel prognostic factors in MM. HUM PATHOL 31:1341-1345.

Palliative and therapeutic activity of IL-2 immunotherapy in unresectable malignant pleural mesothelioma with pleural effusion: Results of a phase II study on 31 consecutive patients.

Malignant pleural mesothelioma is often unresectable at diagnosis, is refractory to cytotoxic agents and is frequently complicated by pleural effusion. The expected survival range for patients with or without involvement of visceral pleura is respectively 1-9 and 9-12 months; mesothelioma-related pleural effusion severely impairs the patients' quality of life and easily relapses after conservative treatments. Intrapleural administration of IL-2 is reported to be effective both in tumor-associated malignant pleurisy and on primary mesothelioma, whereas few data exist about IL-2 systemic administration. In order to assess the palliative and therapeutic activity of IL-2 in unresectable pleural malignant mesothelioma with pleural effusion, we performed a phase II study on 31 consecutive patients (M/F 16/15; median age 61 years, range 40-84; PS ECOG 0 n=7; ECOG 1 n=15; ECOG 2 n=9; stage IA n=13; IB n=9; II n=7; IV=2) who received first-line therapy with intrapleural repeated instillation of 9000000 I.U. IL-2 twice/weekly for 4 weeks, after needle thoracenthesis. In nonprogressing patients, 3000000 I.U. IL-2 were subcutaneously administered thrice weekly for up to 6 months. Toxicity (WHO criteria) with intrapleural IL-2 consisted of grade 3 fever in 6/31 (19%) patients and of cardiac toxicity (failure) grade 3 in one patient (3%); toxicity during subcutaneous treatment was mild to moderate, mainly a flu-like syndrome. In 28/31 (90%) of patients there was no further or minimal (asymptomatic) pleural fluid collection (according to Paladine criteria); pleurisy relapsed only in 1/28 patients after 19 months. Tumor objective response (WHO criteria), evaluated by CT, occurred in seven patients (one CR and six PR; ORR 22%); ten patients achieved SD and 14 patients progressed. Median overall survival was 15 months (range 5-39) in all patients. IL-2 intrapleural administration followed by low-dose IL-2 subcutaneously in pleurisy-complicated malignant mesothelioma is feasible and active both in palliation of pleural effusion and on primary tumor, with manageable toxicity. The overall survival observed in nonprogressing patients warrants further randomized studies with IL-2 aimed to the patient outcome.

Simian virus 40 is not a cofactor in the pathogenesis of environmentally induced malignant pleural mesothelioma in Turkey.

Malignant pleural mesothelioma (MPM) continues to be a public health problem in Turkey, where exposure to environmental asbestos and fibrous zeolite (erionite) is the main cause of the disease. However, less than 5% of exposed individuals develop the disease, and numerous cases of MPM are documented each year in which the patient has no known exposure to either of these minerals. Thus, additional unknown factors act independently or as co-carcinogens in the development of MPM. Simian Virus 40 (SV40) may act as a co-carcinogen with asbestos in the pathogenesis of occupationally induced MPM. To determine if SV40 plays a role in the development of MPM in Turkey, we used PCR analysis to investigate if SV40 DNA sequences were present in 29 mesothelioma specimens from patients previously exposed to asbestos or erionite. PCR analysis revealed that all 29 tissue specimens from our patients did not contain SV40 DNA. 15 specimens from patients suffering from tuberculosis pleuresy were also SV40 negative. One mesothelioma and one osteosarcoma from Italy tested positive for SV40. Our results indicate that inorganic fibers, asbestos, and erionite remain the only known causal factors of mesothelioma in Turkey. The absence of SV40 in Turkish specimens and its presence in Italian specimens may be related to the fact that SV40-contaminated vaccines were not administered in Turkey.

Simian virus 40 and human cancer.

Deoxyribonucleic acid (DNA) oncoviruses can induce neoplastic transformation by interfering with proliferative proteins. Simian virus 40 (SV40) has been shown to induce brain tumors, osteosarcoma, lymphoid tumors and malignant mesothelioma in hamsters and SV40-like DNA sequences corresponding to the Rb-pocket binding domain of SV40 T-antigen (Tag) have been detected in the same human tumors. Since only a small percentage of people exposed to asbestos fibers develop a malignant mesothelioma, SV40 has been suspected to co-operate with the fibers in the neoplastic transformation or even to itself induce the onset of malignant mesothelioma in patients without expositive history. The mechanism that seems to be involved in the SV40-induced carcinogenesis process is mediated by interaction of Tag, both with p53 and Rb proteins, leading to their functional inactivation that is responsible for the removal of their inhibitory cell cycle effect which determines the increase of the number of cells entering the G1-S phase. Up to now the source of SV40 human infections has not yet been completely identified even though administration from 1957-1965 of SV40 contaminated polio vaccines is highly suspected. Horizontal infection by sexual transmission has been also hypothesized. Due to the important public health implications further investigations are required in order to establish both the source and the carcinogenetic role of simian virus 40 in humans.

Immunobiology and immune defense mechanisms of mesothelioma cells.

Malignant mesothelioma (MM) is an aggressive tumor whose incidence is expected to rise in future years. Patients with this neoplasm have a poor prognosis. Immunotherapy has been shown to be effective in some neoplasms (e.g. melanoma), significantly improving their prognosis but we do not yet have sufficient data on the capability of MM cells to elicit an immune response. A "three step" event is required to determine an immune response: adhesion, recognition, and costimulation between the antigen presenting cells and the immunoeffector cells. Lack of one of these three steps leads to a defective immune response. The most important mechanism determining the defective immune response to the tumor cells is supposed to be the deficiency of the molecules involved in this "three step event", the release of immuno-depressant factors by the tumor cells and/or the tumor infiltrating cells and the lack of surface immunogen epitopes. Investigations on MM cells are not univocal, suggesting that, at least in some cases, an effective immune response to this neoplasm can occur. Blocking the release of immunodepressant factors by malignant mesothelioma cells and identification of effective, specific immunogen epitopes seem to be the most promising objective to achieve.

Recurrent chromosome 6 abnormalities in malignant mesothelioma.

The long latency period between asbestos exposure and the onset of malignant mesothelioma (MM) suggests that a multistep tumorigenesis process occurs whilst the capability of asbestos fibres to interfere directly with chromosomes focuses on the critical role of the chromosomal abnormalities in this neoplasm. The aim of our study was to identify any recurrent chromosomal changes in ten primary MM cell cultures derived from pleural effusions of patients with MM from the same geographic area and environmental and/or occupational exposure to asbestos fibers. Cytogenetic analysis was performed in accordance with International System for Human Cytogenetic Nomenclature. Our results confirmed a great number of cytogenetic abnormalities in MM cells. Recurrent loss of the long arms of chromosome 6 (6q-) was the most frequent abnormality detected (four epithelial and two mixed subtypes) while, on the whole, abnormalities of chromosome 6 were found in nine out of ten cases whereas chromosome 6 was normal only in the case with fibromatous subtype. Monosomy 13 and 17 was found in five cases, monosomy 14 in four cases and 22 in three cases. Since deletion of 6q- was detected even in relatively undisturbed karyotype, we hypothesize a multistep carcinogenic process in which deletion of 6q- is an early event in the development and progression of malignant mesothelioma.

Human malignant mesothelioma of the pleura: new perspectives for diagnosis and therapy.

The ability to immortalize human mesothelioma cells in vitro with simian virus (SV) 40 and the fact that SV40 induces mesotheliomas in hamsters prompted us to look for SV40 deoxyribonucleic acid (DNA) sequences in human mesotheliomas. In a previous study, we found that over half (29/48) of human malignant pleural mesotheliomas contained SV40-like sequences whereas only a few (3/47) control samples contained the same detectable sequences. The SV40 genome encodes the 90 KD nuclear large T-antigen (Tag) and the 17 KD small-t antigen (tag), responsible for SV40's transforming and oncogenic properties. These antigens block tumour suppressor gene products, such as p53. We considered the possibility of reverting this effect by adding exogenous wild-type p53 and thus restoring normal cell functions. For this purpose, we developed a recombinant adenovirus carrying complementary DNA (cDNA) for wild type p53 (AdCMV.p53) and infected mesothelioma cell lines with this virus. Inhibition of proliferation, halting of the cell cycle and massive apoptosis was observed in all mesothelioma cell lines tested. In addition, proliferation of human mesothelioma tumours into nude mice was inhibited by in vivo adenovirus-mediated p53 transgene expression. We also report preliminary evidence of expression, by immunoreactivity, of the extracellular matrix protein tenascin in human malignant pleural mesotheliomas. It was interesting to find predominant tenascin positivity at the tumour's invasive edge and in areas of tumour vascularization. This preliminary report suggests that adenovirus-mediated p53 hyperexpression counteracts transforming properties of the large T-antigen and suggests that gene therapy may be useful in treating human malignant mesothelioma.

The biological activities of simian virus 40 large-T antigen and its possible oncogenic effects in humans.

Simian virus 40 (SV40) is an oncogenic virus which induces tumors in hamsters and transforms human cells in tissue culture. Between 1955 and 1963, polio vaccines and adenovaccines were contaminated with SV40; therefore, millions of people were exposed to this oncogenic virus. The SV40 proteins responsible for in vivo oncogenesis and in vitro cell transformation are encoded by the early region of the virus. These proteins are called T (tumor) antigens (Tags), because animals with tumors induced by SV40 have antibodies against these viral proteins. Recently, we and other research laboratories have found SV40 in specific types of human tumors: mesothelioma, ependymoma and choroid plexus tumors, osteosarcoma and sarcoma. The same tumor types will develop in hamsters which have been injected systemically with SV40. SV40 causes cell transformation in tissue culture and tumors in animals, because SV40 Tag binds and inactivates the cellular tumor suppressor gene products, Rb and p53. We found that SV40 Tag binds p53 and Rb in human mesotheliomas, possibly contributing to the malignant phenotype.

The detection of simian virus 40 in human tumors by polymerase chain reaction.

Simian virus (SV) 40 is a deoxyribonucleic acid (DNA) virus that induces mesotheliomas, ependymomas, bone tumors, and lymphomas in hamsters. In recent years SV40 sequences have been detected in approximately 60% of mesotheliomas and ependymomas, in 33% of bone tumors and sarcomas, and in 13% of lymphomas. Because the amount of human specimens available for molecular studies is usually minimal, the method most commonly used to demonstrate SV40 in human specimens is the polymerase chain reaction (PCR). PCR is a highly sensitive and useful technique. In the PCR reaction, different sets of primers are used for targeting different regions of DNA. The regions of the SV40 genome targeted by PCR include the large T-antigen, the small t-antigen, the origin of replication, and viral protein-1 capsid protein. The use of these different sets of primers to test human tumor specimens for SV40 produce a different percentage of positive results. This is because these experiments revealed that some primers are more specific than others which may also detect sequences belonging to other DNA papovaviruses. Therefore, the combined use of different sets of primers is recommended when it is important to distinguish SV40 from other related papovaviruses such as BK and JC, which can also be occasionally present in human cells. Furthermore, these experiments demonstrated that polymerase chain reaction analyses for simian virus 40 can be performed better and easier when using deoxyribonucleic acid extracted from fresh and/or frozen tissue. Deoxyribonucleic acid from paraffin embedded specimens should not be used routinely for simian virus 40 testing because of the high risk of obtaining false negative results. However, these paraffin derived deoxyribonucleic acids can be used reliably in molecular laboratories specialized in these type of analyses. This paper describes the methods that we have developed to test simian virus 40 in human specimens.

Estrogen receptor ß activation impairs mitochondrial oxidative metabolism and affects malignant mesothelioma cell growth in vitro and in vivo.

Estrogen receptor (ER)-ß has been shown to possess a tumor suppressive effect, and is a potential target for cancer therapy. Using gene-expression meta-analysis of human malignant pleural mesothelioma, we identified an ESR2 (ERß coding gene) signature. High ESR2 expression was strongly associated with low succinate dehydrogenase B (SDHB) (which encodes a mitochondrial respiratory chain complex II subunit) expression. We demonstrate that SDHB loss induced ESR2 expression, and that activated ERß, by over-expression or by selective agonist stimulation, negatively affected oxidative phosphorylation compromising mitochondrial complex II and IV activity. This resulted in reduced mitochondrial ATP production, increased glycolysis dependence and impaired cell proliferation. The observed in vitro effects were phenocopied in vivo using a selective ERß agonist in a mesothelioma mouse model. On the whole, our data highlight an unforeseen interaction between ERß-mediated tumor suppression and energy metabolism that may be exploited to improve on the therapy for clinical management of malignant mesothelioma.

Will antiangiogenic agents be a future for mesothelioma therapy?

BACKGROUND: Malignant mesothelioma (MM) is an aggressive disease that is diagnosed mostly in locally advanced or metastatic stage. In this condition chemotherapy with the combination cisplatin and pemetrexed or ralitrexed represents the standard treatment as supported by a phase III study. However, chemotherapy has very limited effect on the improvement of survival of patients and very few of the MM patients survive more than 2 years. A better understanding of molecular mechanisms and pathways involved in angiogenesis in MM is the basis for the development of new drugs targeted against these pathways responsible for the proliferation and survival of tumor cells. OBJECTIVE: This review discusses the role of angiogenic factors in tumourigenesis with a particular focus on MM and it summarizes the results of clinical trials on the drugs targeting angiogenic pathways in MM. METHODS: We have used original research articles, abstracts and oral presentations from ASCO (American Society of Clinical Oncology) and the website of clinical trials http://www.ClinicalTrials.gov. RESULTS/CONCLUSIONS: This review summarizes the results of antiangiogenic agents under evaluation in clinical trials. A better understanding of the angiogenic pathways activated in MM will hopefully provide new therapeutic options for these patients in the future.