Greillier L, Marco S, Barlesi F.

Service d’Oncologie Multidisciplinaire et Innovations Thérapeutiques, Université de la Méditerranée-Assistance Publique Hôpitaux de Marseille, Marseille, France.

Abstract

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis, whose exposure to asbestos fibers is the main etiology. The incidence of MPM is anticipated to increase worldwide during the first half of this century. MPM is notoriously refractory to most treatments, and the only standard of care is cisplatin and antifolate first-line chemotherapy. The urgent need for additional therapeutic agents, in parallel with advances in the knowledge of the molecular events of oncogenesis, has resulted in the development of the so-called ‘targeted agents’ that specifically inhibit critical pathways in malignant cells and in their microenvironment. We carried out a comprehensive review of the literature from January 2000 to May 2010 on studies that assessed targeted agents for the systemic treatment of MPM. Although tyrosine kinase inhibitors directed against the epidermal growth factor and the platelet-derived growth factor receptors did not show significant clinical activity in phase II studies, some other targeted therapies seemed promising, notably histone deacetylase inhibitors and antiangiogenic agents. However, none of these has yet reached daily practice. That is the reason why efforts must continue in the area of clinical and translational research for MPM.

Yano S, Li Q, Wang W, Yamada T, Takeuchi S, Nakataki E, Ogino H, Goto H, Nishioka Y, Sone S.

Division of Medical Oncology, Cancer Research Institute, Kanazawa University. Kanazawa, Ishikawa 920-0934.

Abstract

Malignant pleural mesothelioma (MPM), arises from the mesothelial cells, is difficult to be diagnosed at an early stage, and is refractory to conventional chemotherapy and radiotherapy. Therefore, the establishment of novel effective therapies is necessary to improve the prognosis for many patients with this disease. Recent studies have demonstrated that angiogenesis plays a significant role in MPM progression, suggesting the importance of tumor vessels as therapeutic targets. To explore molecular pathogenesis and evaluate the efficacy of vascular targeting therapy in MPM, we developed orthotopic implantation SCID mouse models of MPM. We found that selective VEGF inhibitors were effective only in the treatment of high-VEGF-producing MPM models. On the other hand, multiple kinase inhibitor E7080, with inhibitory activity against various angiogenic cytokine receptors, suppressed the progression and prolonged survival of both high-VEGF-producing and low-VEGF-producing MPM models. Further understanding of the functional characteristics of tumor angiogenesis may be essential to improve targeting therapies in MPM. In this review, we introduce current status of clinical strategies and novel therapeutic approaches against angiogenesis in MPM.

Ramalingam SS, Belani CP, Ruel C, Frankel P, Gitlitz B, Koczywas M, Espinoza-Delgado I, Gandara D.

Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, Georgia, USA. suresh.ramalingam@emory.edu

Abstract

Background: Belinostat (PXD 101) is a novel inhibitor of class I and II histone deacetylases. This class of compounds has demonstrated anticancer activity in malignant mesothelioma. We conducted a phase II study of belinostat in patients with relapsed malignant pleural mesothelioma.

Methods: Patients with advanced mesothelioma, progression with one prior chemotherapy regimen and Eastern Cooperative Oncology Group performance status 0-2 were eligible. Belinostat was administered at 1000 mg/m intravenously over 30 minutes on days 1-5 of every 3 week cycle. The primary end point was response rate. The Simon two-stage design was used. Disease assessments were performed every two cycles.

Results: Thirteen patients were enrolled. Baseline characteristics were: median age of 73 years; Eastern Cooperative Oncology Group performance status 0 (n = 4), 1 (8) and 2 (1). A median of two cycles of therapy were administered. Disease stabilization was seen in two patients. No objective responses were noted and the study did not meet criteria to proceed to the second stage of accrual. Median survival was 5 months with a median progression-free survival of 1 month. Salient toxicities included nausea, emesis, fatigue, and constipation. One patient died as a consequence of cardiac arrhythmia which was deemed ‘possibly’ related to therapy.

Conclusions: Belinostat is not active as monotherapy against recurrent malignant pleural mesothelioma. Evaluation of combination strategies or alternate dosing schedules may be necessary for further development of this novel agent in mesothelioma.

Pass HI, Brewer GJ, Dick R, Carbone M, Merajver S.

Department of Cardiothoracic Surgery, New York University School of Medicine, New York, New York 10016, USA. harvey.pass@med.nyu.edu

Abstract

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.

Salzberg M, Kirson E, Palti Y, Rochlitz C.

University Hospital Basel, Switzerland. msalzberg@pharmabrains.ch

Abstract

Background: The transmission of electric fields using insulated electrodes has demonstrated that very low-intensity, properly tuned, intermediate-frequency electric fields, termed tumor-treating fields (TTFields), selectively stunts tumor cell growth and is accompanied by a decrease in tumor angiogenesis.

Patients and Methods: This open, prospective pilot study was designed to evaluate the safety, tolerability, and efficacy profile of TTFields treatment in patients with locally advanced and/or metastatic solid tumors using the NovoTTF100A^TM device. All 6 patients were heavily pre-treated with several lines of therapy; no additional standard treatment option was available to them. TTFields treatment using continuous NovoTTF-100A lasted a minimum of 14 days and was very well tolerated.

Results: No related serious adverse events occurred. Outcomes showed 1 partial response of a treated skin metastasis from a primary breast cancer, 3 cases where tumor growth was arrested during treatment, and 1 case of disease progression. One mesothelioma patient experienced lesion regression near TTFields with simultaneous tumor stability or progression in distal areas.

Conclusion: Although the number of patients in this study is small, the lack of therapy toxicity and the efficacy observed in data gathered to date indicate the potential of TTFields as a new treatment modality for solid tumors, definitely warranting further investigation.

Nikolinakos P, Heymach JV.

Department of Thoracic/Head and Neck Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009, USA. jheymach@mdanderson.org

Abstract

Cediranib (AZD2171; Recentin, AstraZeneca, Wilmington, Delaware) is a once-daily oral tyrosine kinase inhibitor that targets vascular endothelial growth factor receptors 1, 2, and 3, c-KIT, and platelet-derived growth factor receptors. In preclinical testing it inhibits tumor angiogenesis and inhibits tumor growth in a wide range of tumor models. Phase 1 studies show cediranib to be generally well tolerated as monotherapy at doses of 45 mg/d or less, with a pharmacokinetic profile that supports once-daily oral administration and toxic effects consistent with those seen in other agents that target the vascular endothelial growth factor pathway. Encouraging results from phase 1 studies as monotherapy or in combination with chemotherapy have prompted further investigation in several thoracic malignancies, including ongoing trials in malignant mesothelioma, small cell lung cancer, and an ongoing phase 2/3 trial in non-small cell lung cancer (NSCLC) in combination with chemotherapy. The NSCLC trials include patients with squamous cell histologic features and treated brain metastases, populations for which bevacizumab is currently not indicated. These trials will determine whether cediranib will join the growing armamentarium of therapeutic options for thoracic malignancies and broaden the number of patients with NSCLC who could potentially benefit from antiangiogenic therapy.

Giesel FL, Choyke PL, Mehndiratta A, Zechmann CM, von Tengg-Kobligk H, Kayser K, Bischoff H, Hintze C, Delorme S, Weber MA, Essig M, Kauczor HU, Knopp MV.

Radiologie, German Cancer Research Center (DKFZ), INF 280, 69120 Heidelberg, Germany; Ohio State University, Columbus, OH.

Abstract

Rationale and Objectives: Malignant mesothelioma (MM) of the pleura is an aggressive and often fatal neoplasm. Because MM frequently demonstrates marked angiogenesis, it may be responsive to antiangiogenic therapy, but effective methods for selecting and monitoring of patients are further needed. We employed dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and quantitative immunohistochemistry (IHC) to characterize the microvascularity of MM using both a physiologic and ultrastructural method.

Materials and Methods: Nineteen patients diagnosed with MM were enrolled and DCE-MRI was performed before antiangiogenic treatment. For each patient, tumor regions were characterized by their DCE-MRI–derived pharmacokinetic parameters (Amp, kep, kel), which were also compared to those of normal tissue (aorta, liver, spleen, and muscle). In addition, quantitative IHC of representative samples was performed with CD-34 staining to compare the calculated microvessel density (MVD) results with DCE-MRI results.

Results: MM demonstrated markedly abnormal pharmacokinetic properties compared with normal tissues. Among the parameters tested, Amp was significantly different in MM (P ≤ .001) compared to normal organs. Despite the observation that the MVD of mesotheliomas in this series was high compared to other tumors, DCE-MRI pharmacokinetic parameters had a moderately positive correlation with MVD (r = 0.5).

Conclusions: DCE-MRI and IHC can be used in patients with MM to visualize tumor microvascularity and to characterize tumor heterogeneity. DCE-MRI and IHC results positively correlated, though moderately, but these two methods present as essential tumor biomarkers. This multimodal characterization may be useful in selecting possible tumor subtypes that would benefit from antiangiogenic therapy.

Keywords: Angiogenesis, malignant mesothelioma, dynamic contrast enhanced MRI, pharmacokinetic analysis, microvascular density, CD-34

Amati M, Tomasetti M, Scartozzi M, Mariotti L, Ciuccarelli M, Valentino M, Governa M, Santarelli L.

Università Politecnica delle Marche, Dipartimento di Patologia Molecolare e Terapie Innovative, Clinica di Medicina del Lavoro, Tronto 10/a, 0020 Torrette, AN. m.amati@univpm.it

Abstract

Improved detection methods for diagnosis of asymptomatic malignant pleural mesothelioma (MPM) are essential for an early and reliable detection and treatment of this disease. Thus, focus has been on finding tumour markers in the blood. 94 asbestos-exposed subjects, 22 patients with MM, and 54 healthy subjects were recruited for evaluation of the significance of 8-hydroxy-2′-deoxy-guanosine (80HdG) in white blood cells and plasma concentrations of soluble mesothelin-related peptides (SMRPs), angiogenic factors (PDGFbeta, HGF, bFGF, VEGFbeta), and matrix proteases (MMP2, MMP9, TIMP1, TIMP2) for potential early detection of MM. The area under ROC curves (AUC) indicates that 80HdG levels can discriminate asbestos-exposed subjects from controls but not from MPM patients. Significant AUC values were found for SMRP discriminating asbestos-exposed subjects from MPM patients but not from controls. VEGFbeta can significantly differentiate asbestos-exposed subjects from control and cancer groups. No diagnostic value was observed for MMP2, MMP9, TIMP1, TIMP2. The sensitivity and specificity results of markers were calculated at defined cut-offs. The combination of 80HdG, VEGFbeta and SMRPs best distinguished the individual groups, suggesting a potential indicator of early and advanced MPM cancers. The combination of blood biomarkers and radiographic findings could be used to stratify the risk of mesothelioma in asbestos-exposed populations.

Porret E, Madelaine J, Galateau-Sallé F, Bergot E, Zalcman G.

Service de Pneumologie, Pôle Coeur-Poumons-Vaisseaux, Université Basse-Normandie, CHU de Caen, France.

Abstract

Malignant pleural mesothelioma (MPM) is a rare tumour due to occupational asbestos exposure. The incidence of MPM will continue to increase until 2020-2030. The incidence reaches 100 cases/million/year in occupationally exposed populations as opposed to 1 case/million/year in the general population, leading to 800 to 1,000 cases per year in France. The molecular carcinogenesis of MPM is incompletely understood but alterations to genes NF2, c-met, WT1 RASSF and p16 have been described. These genes are involved in cell invasion and motility, cell division and apoptosis control. Histological diagnosis remains difficult and depends on immunohistochemical analysis as described by the French Mesopath group. Clinical diagnosis relies on thoracoscopy and large pleural biopsies, with increasing use of CT-PET for the evaluation of disease extent. Therapeutic strategy includes prophylactic irradiation following drainage or thoracoscopy to prevent tumour nodule development along drainage channels and puncture sites. In selected patients, extensive extra-pleural pneumonectomy can be performed with curative intent. First line chemotherapy is based on a combination of pemetrexed and cisplatin that has demonstrated an improvement in overall survival and quality of life in phase 3 trials. Antiangiogenic agents such as bevacizumab (Avastatin) may be of interest but need to be tested in phase 3 trials. The Mesothelioma Avastatin Pemetrexed Study (MAPS) is ongoing, coordinated by the French Thoracic Cancer Intergroup (IFCT).

Egleton RD, Brown KC, Dasgupta P.

Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, 1 John Marshall Drive, Huntington, WV 25755, USA.

Abstract

Nicotinic acetylcholine receptors (nAChRs) constitute a heterogeneous family of ion channels that mediate fast synaptic transmission in neurons. They have also been found on non-neuronal cells such as bronchial epithelium and keratinocytes, underscoring the idea that they have functions well beyond neurotransmission. Components of cigarette smoke, including nicotine and NNK [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone], are agonists of nAChRs. Given the association of tobacco use with several diseases, the non-neuronal nAChR signaling pathway has considerable implications for cancer and cardiovascular disease. Recent studies have shown that alpha7 is the main nAChR subunit that mediates the proliferative effects of nicotine in cancer cells. As a result, alpha7 nAChR might be a valuable molecular target for therapy of cancers such as lung cancer and mesothelioma. Future studies involving the design of nAChR antagonists with improved selectivity might identify novel strategies for the treatment of tobacco-related cancers. Here we review the cellular roles of non-neuronal nAChRs, including regulation of cell proliferation, angiogenesis, apoptosis, migration, invasion and secretion.