Pemetrexed plus carboplatin in elderly patients with malignant pleural mesothelioma: combined analysis of two phase II trials

Current drug therapy for pleural mesothelioma

Pleural mesothelioma (PM) is a rare and highly aggressive malignancy originating from the pleural lining, with a median overall survival of merely 1 year. This cancer primarily arises from mesothelial cells following exposure to carcinogenic, biopersistent mineral fibers, particularly asbestos. The histological subtypes of mesothelioma are epithelioid (approximately 60%), sarcomatoid (20%), and biphasic (20%), exhibiting epithelioid and sarcomatoid characteristics. Classification is important for prognosis and guides the therapeutic strategy. Due to the typical late presentation, most patients with PM are ineligible for localized treatments such as surgery or radiotherapy. Systemic therapy, including cytotoxic chemotherapy, targeted therapies, and immunotherapy, is thus critical for managing advanced PM. For unresectable PM, decisions regarding systemic treatment are guided by patient suitability and histological characteristics. First-line therapies for advanced PM currently include the cisplatin-pemetrexed combination and the nivolumab-ipilimumab regimen. Historically, cisplatin-pemetrexed has been administered as first-line treatment, though recent advancements have introduced new therapies that significantly prolong patient survival. Innovative approaches combining immunotherapy and chemotherapy offer promising avenues for further improvement. Future treatment strategies should incorporate novel paradigms, such as combination chemo-immunotherapy, targeted agents, and potential cellular therapies, alongside companion biomarkers tailored to the histologic and molecular diversity of mesothelioma. This review explores the latest advancements in drug therapy for PM and provides an overview of current systemic treatment options.

Targeted Therapy in Mesotheliomas: Uphill All the Way

Mesothelioma (MM) is an aggressive and lethal disease with few therapeutic opportunities. Platinum-pemetrexed chemotherapy is the backbone of first-line treatment for MM. The introduction of immunotherapy (IO) has been the only novelty of the last decades, allowing an increase in survival compared to standard chemotherapy (CT). However, IO is not approved for epithelioid histology in many countries. Therefore, therapy for relapsed MM remains an unmet clinical need, and the prognosis of MM remains poor, with an average survival of only 18 months. Increasing evidence reveals MM complexity and heterogeneity, of which histological classification fails to explain. Thus, scientific focus on possibly new molecular markers or cellular targets is increasing, together with the search for target therapies directed towards them. The molecular landscape of MM is characterized by inactivating tumor suppressor alterations, the most common of which is found in CDKN2A, BAP1, MTAP, and NF2. In addition, cellular targets such as mesothelin or metabolic enzymes such as ASS1 could be potentially amenable to specific therapies. This review examines the major targets and relative attempts of therapeutic approaches to provide an overview of the potential prospects for treating this rare neoplasm.

Pleural Mesothelioma in the Era of Immunotherapy

Over the course of the last decade, immunotherapy has revolutionised the management of a great number of cancer types. The treatment of pleural mesothelioma, a rare and highly aggressive cancer, is also being transformed by immunotherapy. The recent combination of ipilimumab and nivolumab improved overall survival compared with platinum-based chemotherapy, irrespective of the histology, establishing immunotherapy as a front-line standard of care in advanced pleural mesothelioma. Yet, most patients do not derive long-term benefit from any of the available therapies, and we note a significant lack of predictive and prognostic biomarkers. After progressing on first-line therapy, patients have limited therapeutic options, and data are scarce about optimal sequencing. In this perspective, we discuss the current management of pleural mesothelioma, defining what we consider to be the therapeutic sequence based on performance status and tumour histology. We also highlight promising ongoing trials that could further shape the management of this rare disease.

One Third of Malignant Pleural Mesothelioma Shows High Immunohistochemical Expression of MSLN or CXCR4 Which Indicates Potent Candidates for Endo-Radiotherapy

Malignant pleural mesothelioma (MPM) is a mainly asbestos-related tumour associated with a very poor prognosis. Therapeutic approaches include multimodal therapy and chemotherapeutics, with cisplatin being the drug of choice, but response rates of only up to 14% indicate very poor outcomes. Effective treatment options are lacking. Besides the diagnostic usage of radioligands in positron emission tomography (PET)/computed tomography (CT), the endo-radioligand therapy with Lu177 has been proven as a powerful tool in cancer therapy. Mesothelin (MSLN) and C-XC chemokine receptor 4 (CXCR4) are membrane-bound proteins, expressed in certain cancers, and thus are promising targets for endo-radiotherapy. A significant portion of high MSLN- or CXCR4-expressing tumors within the MPM may open the field for this sophisticated treatment approach in the near future. Formalin-fixed, paraffin-embedded (FFPE) tumour specimens from 105 patients suffering from MPM and treated at the Lung Cancer Centre of Essen and at the Helios Klinikum Emil von Behring Berlin were screened. The tumour samples were arranged in tissue microarrays. We immunohistochemically stained the tumour samples against MSLN and CXCR4. The protein expressions of the stainings were scored by a pathologist by using a semiquantitative method. The data obtained were correlated with the clinical outcome. Overall, 77.1% of the analysed tumours showed CXCR4 protein expression (25.7% of them at high expression level (Score 3)). 48.6% of all samples showed an overall strong staining (Score ≥ 2), 59% of the investigated tumours showed MSLN protein expression (10.5% of them at high expression (Score 3)), and 36.2% of all samples showed an overall strong staining (Score ≥ 2). Our results show significant tissue expression levels, for both CXCR4 and MSLN protein, in a major portion of clinical MPM samples. One-third of patients showed outstanding immunoexpression of at least one of these markers, making them interesting candidates for radioligand-based PET/CT diagnostics and follow-up and furthermore may profit from endo-radiotherapy.

Appropriate Supervised Machine Learning Techniques for Mesothelioma Detection and Cure

Mesothelioma is a dangerous, violent cancer, which forms a protecting layer around inner tissues such as the lungs, stomach, and heart. We investigate numerous AI methodologies and consider the exact DM conclusion outcomes in this study, which focuses on DM determination. K-nearest neighborhood, linear-discriminant analysis, Naive Bayes, decision-tree, random forest, support vector machine, and logistic regression analyses have been used in clinical decision support systems in the detection of mesothelioma. To test the accuracy of the evaluated categorizers, the researchers used a dataset of 350 instances with 35 highlights and six execution measures. LDA, NB, KNN, SVM, DT, LogR, and RF have precisions of 65%, 70%, 92%, 100%, 100%, 100%, and 100%, correspondingly. In count, the calculated complication of individual approaches has been evaluated. Every process is chosen on the basis of its characterization, exactness, and calculated complications. SVM, DT, LogR, and RF outclass the others and, unexpectedly, earlier research.

Cancer-Associated Fibroblasts Regulate Kinase Activity in Mesothelioma Cell Lines via Paracrine Signaling and Thereby Dictate Cell Faith and Behavior

BACKGROUND

Malignant pleural mesothelioma (MPM) has an infaust prognosis due to resistance to systemic treatment with platin-analoga. MPM cells modulate the immune response to their benefit. They release proinflammatory cytokines, such as TGF-ß, awakening resting fibrocytes that switch their phenotype into activated fibroblasts. Signaling interactions between cancer cells and cancer-associated fibroblasts (CAFs) play an integral part in tumor progression. This study aimed to investigate the role CAFs play in MPM progression, analyzing the impact this complex, symbiotic interaction has on kinase-related cell signaling in vitro.

METHODS

We simulated paracrine signaling in vitro by treating MPM cell lines with conditioned medium (CM) from fibroblasts (FB) and vice versa. NCI-H2052, MSTO-211H, and NCI-H2452 cell lines representing the three mayor MPM subtypes, while embryonal myofibroblast cell lines, IMR-90 and MRC-5, provide a CAFs-like phenotype. Subsequently, differences in proliferation rates, migratory behavior, apoptosis, necrosis, and viability were used as covariates for data analysis. Kinase activity of treated samples and corresponding controls were then analyzed using the PamStation12 platform (PamGene); Results: Treatment with myofibroblast-derived CM revealed significant changes in phosphorylation patterns in MPM cell lines. The observed effect differs strongly between the analyzed MPM cell lines and depends on the origin of CM. Overall, a much stronger effect was observed using CM derived from IMR-90 than MRC-5. The phosphorylation changes mainly affected the MAPK signaling pathway.; Conclusions: The factors secreted by myofibroblasts in fibroblasts CM significantly influence the phosphorylation of kinases, mainly affecting the MAPK signaling cascade in tested MPM cell lines. Our in vitro results indicate promising therapeutic effects by the use of MEK or ERK inhibitors and might have synergistic effects in combination with cisplatin-based treatment, improving clinical outcomes for MPM patients.

GOECP/SEOR clinical guidelines on radiotherapy for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare tumor with poor prognosis and rising incidence. Palliative care is common in MPM as radical treatment with curative intent is often not possible due to metastasis or extensive locoregional involvement. Numerous therapeutic advances have been made in recent years, including the use of less aggressive surgical techniques associated with lower morbidity and mortality (e.g., pleurectomy/decortication), technological advancements in the field of radiotherapy (intensity-modulated radiotherapy, image-guided radiotherapy, stereotactic body radiotherapy, proton therapy), and developments in systemic therapies (chemotherapy and immunotherapy). These improvements have had as yet only a modest effect on local control and survival. Advances in the management of MPM and standardization of care are hampered by the evidence to date, limited by high heterogeneity among studies and small sample sizes. In this clinical guideline prepared by the oncological group for the study of lung cancer of the Spanish Society of Radiation Oncology, we review clinical, histologic, and therapeutic aspects of MPM, with a particular focus on all aspects relating to radiotherapy, including the current evidence base, associations with chemotherapy and surgery, treatment volumes and planning, technological advances, and reradiation.

Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma

AIMS

To carry out a dosimetric comparison and constraints feasibility proof of adjuvant radiotherapy through helical tomotherapy or volumetric modulated arc therapy (VMAT) for malignant pleural mesothelioma patients after pleurectomy/decortication.

MATERIALS AND METHODS

Retrospective calculations were carried out on previously acquired simulations. A whole-pleura volume with 50.4 Gy in 28 fractions was prescribed, simulating a no residual tumour situation. Calculations were carried out using an anisotropic analytical algorithm with a 2.0 mm grid. Beam-on time, planning target volume (PTV) coverage, homogeneity index and organ at risk exposure were compared.

RESULTS

Sixteen patient plans were calculated per device. Constraints were met overall by both modalities. For helical tomotherapy and VMAT plans, median beam-on times were 13.8 (11.6-16.1) min and 6.4 (6.1-7.0) min; P = 0.006. The median left-sided radiotherapy PTV D₉₈ were 48.1 (48.0-48.8) Gy and 47.6 (46.5-48.3) Gy; P = 0.023. No significant difference for right-sided radiotherapy was found. PTV D₂ for left-sided radiotherapy was higher with VMAT (P = 0.014). For right-sided radiotherapy, helical tomotherapy showed higher doses (P = 0.039). No homogeneity index differences for left-sided radiotherapy (P = 1.00) and right-sided radiotherapy (P = 0.598) were seen. Significant organ at risk exposure differences were found on left-sided radiotherapy whole-lung V_20, as well as D₅₀ (both P = 0.008). Higher contralateral lung and ipsilateral kidney exposures were found with VMAT plans for both treatment sides.

CONCLUSION

Adjuvant radiotherapy after pleurectomy/decortication in malignant pleural mesothelioma patients, with a VMAT- or helical tomotherapy-based platform, is dosimetrically feasible. Lung sparing was mostly improved with helical tomotherapy. Technique selection must be carried out according to availability and clinical criteria.

Pleural mesothelioma (PM) - The status of systemic therapy

Pleural mesothelioma (PM) remains a malignancy with poor prognosis. Despite initial disappointing response rates to single-agent chemotherapy, upfront platinum and anti-folate-based combination chemotherapy has remained the backbone of treatment for PM for the last three decades. The role of maintenance chemotherapy remains unclear; switch-maintenance gemcitabine has shown improvements in progression-free but not overall survival. The addition of antiangiogenic agents to chemotherapy yielded modest improvements in survival, both upfront in combination with platinum-pemetrexed, and in the relapsed setting. Immunotherapy, particularly PD-(L)1 inhibitors, has shown important but variable effectiveness in relapsed PM when used as monotherapy, and is an important salvage treatment after first-line chemotherapy. Furthermore, the randomized phase 3 trial of ipilimumab-nivolumab versus platinum-pemetrexed chemotherapy demonstrated improved overall survival favouring ipilimumab-nivolumab (HR 0.74, 96.6% CI 0.60-0.91; p = 0.0020), establishing this regimen as the new standard first-line treatment for PM, particularly in those with non-epithelioid histology. Increased interest in PM genomics has led to development of novel personalized therapeutics, such as those targeting DNA repair and EZH2 pathways, however with variable outcomes in trials. Targeting the membrane glycoprotein mesothelin and arginine deprivation are other important strategies under ongoing investigation. The field of PM is changing and new treatments bring hope to a largely lethal and poor prognostic malignancy. Despite these developments, current challenges include understanding the role of combination and multimodality treatments, drivers of resistance to treatment, and establishing predictive biomarkers to improve patient selection and treatment sequencing.

The minimum standard of care for managing malignant pleural mesothelioma in developing nations within the Asia-Pacific Region

Malignant pleural mesothelioma (MPM) is an incurable malignancy associated with high symptom burden and poor prognosis. The relationship between asbestos exposure and MPM incidence is well-established. The incidence rate of MPM in Australia and New Zealand is among the highest globally. Matching the experience of other nations with legal restrictions on asbestos, incidence is expected to fall. In contrast, the incidence of MPM is rising in the developing nations of the Asia-Pacific as consumption and mining (albeit to a lesser extent) of asbestos continues. The incidence of MPM in these nations is currently low or unknown, reflecting insufficient latency periods since industrial use of asbestos, deficient resources for accurate diagnosis, and lack of occupational disease or cancer registries. The landscape of treatment for MPM is rapidly changing with combination immunotherapy now demonstrating improved survival in the first-line setting. Considering vast global inequity in access to anticancer treatments, establishing minimum standard of care for MPM in developing nations is of greater significance. Here, we review the evidence that form the basis of our minimum-standard recommendations for diagnosis, systemic treatment, management of recurrent pleural effusions, and symptom management. We also briefly review evidence-based treatment that may be considered for those with access.

Immune checkpoint inhibitors for unresectable malignant pleural mesothelioma

Unresectable malignant pleural mesothelioma (MPM) is an aggressive disease with a 5-year survival rate of approximately 10%. Recent data suggest that MPM is an immunologically active tumor, in which checkpoint inhibition through the blockade of the anti-cytotoxic T lymphocyte antigen-4 (-CTLA-4) or anti-programmed cell death 1 (PD-1) could play a major therapeutic role. Initially, clinical trials evaluated immune checkpoint inhibitors (ICIs) in the salvage setting after platinum-based chemotherapy with mixed results in terms of efficacy. More recently, the combination of the anti-CTLA-4 agent ipilimumab plus the anti-PD-1 agent nivolumab was tested in the front-line setting, and reported a superior survival as compared to platinum/pemetrexed. While other clinical trials ore ongoing in order to investigate ICIs for MPM, it seems now evident that we have entered a new "era" for the treatment of MPM. In the future, a few issues need to be solved with regard to the use of ICIs for MPM. Among them, there is the identification of biomarkers of sensitivity to immunotherapy that may help enrich the patient population who could benefit the most from treatment, while avoiding for some other patients the potential occurrence of immune-related side effects from therapies that are anticipated to be ineffective.

Bevacizumab plus cisplatin/pemetrexed then bevacizumab alone for unresectable malignant pleural mesothelioma: A Japanese safety study

Aims

Malignant pleural mesothelioma (MPM) is an aggressive malignancy with poor prognosis and limited treatment options. Cisplatin plus pemetrexed is the only approved first‐line treatment for patients with unresectable MPM. Recently, promising outcomes were observed with first‐line bevacizumab combined with cisplatin/pemetrexed, leading to the recommendation of this regimen as a first‐line treatment option for patients with MPM. Bevacizumab plus cisplatin/pemetrexed has been shown to be safe and effective in non–small cell lung cancer, however, there are no efficacy or safety data in Japanese patients with MPM treated with this regimen. We conducted a multicenter study to evaluate tolerability and safety for Japanese patients with chemotherapy‐naïve, unresectable MPM.

Methods

Eligible patients (n = 7) received bevacizumab plus cisplatin/pemetrexed (up to six cycles), then single‐agent bevacizumab until disease progression or onset of unacceptable adverse events (AEs), according to the 3+3 design analogy.

Results

One patient (14.3%) reported an AE (gastric ulcer) meeting tolerability criteria. All patients experienced gastrointestinal disorders, including nausea (grade 1/2 only, n = 6, 85.7%) and constipation (grade 1/2 only, n = 5, 71.4%). Five patients (71.4%) had grade 3 hypertension. Two patients discontinued treatment due to gastric ulcer (n = 1) and proteinuria (n = 1). At data cut‐off, four patients had stable disease, two had partial response and one had non‐complete response/non‐progressive disease due to the absence of target lesions.

Conclusions

Bevacizumab plus cisplatin/pemetrexed then bevacizumab was well tolerated in Japanese patients with MPM.

Randomized Study of Maintenance Pemetrexed Versus Observation for Treatment of Malignant Pleural Mesothelioma: CALGB 30901

BACKGROUND

The role of maintenance therapy for malignant pleural mesothelioma (MPM) is unknown. We performed a randomized phase II trial to determine if continuation of pemetrexed after first-line pemetrexed and platinum would improve progression-free survival (PFS).

PATIENTS AND METHODS

Eligible patients with unresectable MPM, without disease progression following 4 to 6 cycles of pemetrexed and platinum were randomized 1:1 to observation or continuation of pemetrexed until progression, stratified by number of cycles (< 6 or 6), cis- or carboplatin containing regimen, and histology. Study size was calculated based on the assumption that observation would produce a median PFS of 3 months and pemetrexed would yield median PFS of 6 months.

RESULTS

A total of 72 patients were registered from December 2010 to June 2016. The study closed early after 53 patients were randomized; 49 eligible (22 on the observation arm and 27 on the pemetrexed arm) were included in the analysis. The median PFS was 3 months (95% confidence interval [CI], 2.6-11.9 months) on observation and 3.4 months (95% CI, 2.8-9.8 months) on pemetrexed (hazard ratio [HR], 0.99; 95% CI, 0.51-1.90; P = .9733). The median overall survival (OS) was 11.8 months (95% CI, 9.3-28.7 months) for observation, and 16.3 months (95% CI, 10.5-26.0 months) for pemetrexed (HR, 0.86; 95% CI, 0.44-1.71; P = .6737). Grade 3 or 4 toxicities on the pemetrexed arm included anemia (8%), lymphopenia (8%), neutropenia (4%), and fatigue (4%). A higher baseline level of soluble mesothelin-related peptide was associated with worse PFS (HR, 1.86; 95% CI, 1.00-3.46; P = .049).

CONCLUSION

Maintenance pemetrexed following initial pemetrexed and platinum chemotherapy does not improve PFS in patients with MPM.

Clinical Implementation of a Free-Breathing, Motion-Robust Dynamic Contrast-Enhanced MRI Protocol to Evaluate Pleural Tumors

OBJECTIVE. The purpose of this study was to develop a motion insensitive clinical dynamic contrast-enhanced MRI (DCE-MRI) protocol to assess the response of pleural tumors in clinical trials. MATERIALS AND METHODS. Thirty-two patients with pleura-based lesions were administered contrast material and imaged with gradient-recalled echo DCE-MRI sequence variants: either a traditional cartesian k-space acquisition (FLASH), a time-resolved imaging with stochastic trajectories acquisition (TWIST), or a radial stack-of-stars acquisition (radial) sequence in addition to other standard-of-care imaging sequences. Each image acquisition's sensitivity to motion was evaluated by comparing the motion of the thoracic border in 3D throughout the acquisition. One-way ANOVA was used to compare the image quality between different acquisitions. The 95% CIs were calculated for mean thoracic border displacement. The effects of motion on kinetic parameter estimation were explored with simulations according to clinically acquired data. RESULTS. Radial was the most motion-robust sequence with subvoxel mean displacement in the superior-inferior direction (0.4 ± 1.2 [SD] mm). FLASH showed intermediate displacement (4.6 ± 2.0 mm), whereas TWIST was most sensitive to motion (6.4 ± 3.4 mm). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images acquired with the radial sequence were on par or better than the FLASH and TWIST sequences when reconstructed with an improved density compensation algorithm. Simulations showed that motion on scans showing pleural-based lesions can lead to markedly inaccurate kinetic parameter estimation and inappropriate kinetic model convergence within a nested model analysis. CONCLUSION. A practical radial k-space trajectory sequence that provides motion-insensitive pharmacokinetic parameters was incorporated as part of the DCE-MRI protocol of pleural tumors. Validation and usefulness in clinical trials assessing response to therapy is needed.

Clinical Trials Eligibility of Patients With Malignant Pleural Mesothelioma: Use of Novel Therapies and Outcomes

INTRODUCTION

Studies of bevacizumab and pembrolizumab in the treatment of malignant pleural mesothelioma suggest anticancer efficacy; clinical trial populations are not reflective of real-world patients. We aimed to determine the proportion of real-world patients who would be eligible for trials, identify patients who participated in clinical trials, and examine treatment and outcome data.

PATIENTS AND METHODS

Consecutive patients with unresectable malignant pleural mesothelioma seen at our center from January 2012 to July 2018 were assessed with regards to their eligibility for Mesothelioma Avastin Cisplatin Study (MAPS) and KEYNOTE-028 clinical trials. Prognostic information, treatment use, and overall survival (OS) data were also collected.

RESULTS

A total of 133 patients were included: 50% and 37%, respectively, did not meet trial eligibility for MAPS or KEYNOTE-028, most commonly owing to age ≥75 (23%), Eastern Cooperative Oncology Group performance status of ≥2 (21%), concomitant medication (21%), or comorbidity (12%). MAPS eligibility did not correlate with use of bevacizumab (P = .30) or improved OS (P = .87). Eligibility for KEYNOTE-028 correlated with pembrolizumab use (P < .001), but not improved OS (P = .21). Patients who received an investigational anticancer therapy on any clinical trial had improved OS: 32.4 (95% CI, 23.9-40.9) months versus 20.5 (95% CI, 15.8-25.3) months (P = .01).

CONCLUSION

Only ≤63% of our patients were eligible for these trials, highlighting the differences between real-world patients and the highly select trial population. Our patients who participated in clinical trials had superior OS, further emphasizing the selection bias in the trial population.

Screening of Pleural Mesothelioma Cell Lines for Kinase Activity May Identify New Mechanisms of Therapy Resistance in Patients Receiving Platin-Based Chemotherapy

Background

Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumor associated with a dismal prognosis. Multimodal therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons underlying the rather poor efficacy of platinum compounds remain largely unknown. Kinase activity might influence cellular response to these regimens.

Materials and Methods

For this exploratory study, we screened MPM cell lines (NCI-H2452, NCI-H2052, and MSTO-211H) differing in response to cisplatin and benign control fibroblasts (MRC-5) for overall phosphorylation patterns as well as kinase activity with respect to cellular response to cisplatin-based therapeutics. We analysed the cell lines for cellular kinases in a high-throughput manner using the highly innovative technique PamGene. Cell state analysis including apoptosis, necrosis, and cell viability was performed by using enzyme activity and fluorescent-based assays.

Results

Cisplatin alters cellular phosphorylation patterns affecting cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis. In cisplatin-responsive cell lines, phosphorylation of AKT1 and GSK3B was decreased but could not be influenced in cisplatin-resistant NCI-H2452 cells. Cisplatin-responsive cell lines showed increased phosphorylation levels of JNK1/2/3 but decreased phosphorylation in cisplatin-resistant NCI-H2452 cells.

Conclusion

Kinase phosphorylation and activity might play a crucial role in cellular response to cytostatic agents. Cisplatin influences phosphorylation patterns with distinct features in cisplatin-resistant cells. These alterations exert a significant impact on cell cycle, migration, adhesion, signal transduction, immune modulation, and apoptosis of the respective tumor cells. Based on our results, the induction of p38 or JNK1/3, or inhibition of AKT1 by, for example, BIA-6, might offer a positive synergistic effect by induction of an apoptotic response to cisplatin-based treatment, thus potentially enhancing the clinical outcome of MPM patients.

Tumour Treating Fields in combination with pemetrexed and cisplatin or carboplatin as first-line treatment for unresectable malignant pleural mesothelioma (STELLAR): a multicentre, single-arm phase 2 trial

BACKGROUND

Tumour Treating Fields (TTFields) are a regional, antimitotic treatment for solid tumours, which is based on the delivery of low-intensity alternating electric fields. The aim of the STELLAR study was to test the activity of TTFields delivered to the thorax in combination with systemic chemotherapy for the front-line treatment of patients with unresectable malignant pleural mesothelioma.

METHODS

STELLAR was a prospective, single-arm, phase 2 trial done at 12 European academic and non-academic sites (five in Italy, three in Poland, one in France, one in Belgium, one in Spain, and one in the Netherlands) for treatment-naive patients with histologically confirmed unresectable malignant pleural mesothelioma. Patients were aged at least 18 years, had an Eastern Cooperative Oncology Group performance status of 0-1, and at least one measurable or evaluable lesion according to modified Response Evaluation Criteria in Solid Tumors for mesothelioma. Patients received continuous TTFields at a frequency of 150 kHz to the thorax and concomitant chemotherapy with intravenous pemetrexed (500 mg/m² on day 1) plus intravenous platinum (either cisplatin 75 mg/m² on day 1 or carboplatin area under the curve 5 on day 1) every 21 days for up to six cycles. Patients not progressing after completion of chemotherapy received TTFields as maintenance treatment until progression, patient or physician decision, or unacceptable toxic effects. The primary endpoint of the trial was overall survival. Survival analyses were done in the intention-to-treat population, and safety analyses were done in all patients who received at least 1 day of TTFields treatment. This trial is registered with ClinicalTrials.gov, NCT02397928.

FINDINGS

Between Feb 9, 2015 and March 21, 2017, 80 patients were enrolled in the study. Median follow-up was 12·5 months (IQR 7·4-16·6). Median overall survival was 18·2 months (95% CI 12·1-25·8). The most common grade 3 or worse adverse events were anaemia (nine [11%] patients), neutropenia (seven [9%]), and thrombocytopenia (four [5%]). Skin reaction was the only adverse event associated with TTFields and was reported as grade 1-2 in 53 (66%) patients, and as grade 3 in four (5%) patients. No treatment-related deaths were observed.

INTERPRETATION

The trial showed encouraging overall survival results, with no increase in systemic toxicity. TTFields (150 kHz) delivered to the thorax concomitant with pemetrexed and platinum was an active and safe combination for front-line treatment of unresectable malignant pleural mesothelioma. Further investigation in a randomised trial is warranted.

FUNDING

Novocure.

Approved and emerging treatments of malignant pleural mesothelioma in elderly patients

Introduction: Malignant pleural mesothelioma (MPM) is a rare neoplasm with asbestos exposure as the dominant etiologic agent. Owing to the long latent period following exposure, MPM is often diagnosed late in life. Despite this, elderly patients are under-represented in clinical trials. To date, data regarding the tolerability and efficacy of anticancer treatments for elderly patients affected by MPM are still lacking.Areas covered: The current state-of-the-art of approved treatments employed in the treatment of MPM elderly patients is reviewed and discussed, with a look to emerging therapies. A structured search of bibliographic databases for peer-reviewed research literature and of main meeting abstracts using a focused review question was undertaken.Expert opinion: Even though the median age of MPM patients enrolled in the most recent experimental trials is increasing, no specific analysis has been reported so far in the elderly. Moreover, no data are available for the 'oldest of the elderly' (>75 years). Treatment of elderly patients with MPM is one of the major challenges to the clinician. There is a clear need of large, well-conducted retrospective studies and above all of prospective investigations in this patient population, both in the first-and in the second-line setting.

Emerging therapies in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare cancer of the pleural surfaces frequently related to asbestos exposure. It is characterized by a poor prognosis even for patients treated with trimodality therapy, including surgery, chemotherapy and radiotherapy. Moreover, the majority of patients are not candidates for surgery due to disease advanced stage or medical comorbidities. For these patients, the survival rate is even lower and few therapeutic options are currently available. Nevertheless, many interesting novel approaches are under investigation, among which immunotherapy represents one of the most promising emerging strategies. In this review, we will discuss the role of new therapeutic options, particularly immunotherapy, and present the results of the most important and promising clinical trials.

Immune checkpoint inhibition for the treatment of mesothelioma

INTRODUCTION

Combination chemotherapy is currently standard care for advanced mesothelioma. Checkpoint blockade is a promising new treatment.

AREAS COVERED

This review covers clinical use and biomarkers of checkpoint blockade. Medline search used keywords 'mesothelioma' combined with 'checkpoint blockade' OR 'PD-L1' OR 'PD1' OR 'anti-CTLA4'; the search terms AND 'clinical trial' or AND 'biomarker*' were added. Handsearching covered abstracts from relevant meetings from 2016 to 2018 and reference lists. Data informed a narrative review.

EXPERT OPINION

Single agent anti-CTLA4 blockade is inactive in mesothelioma. Single agent PD-1 blockade as second or subsequent treatment gives 20-29% partial responses; no randomized comparisons against placebo or chemotherapy are available. Biomarkers of response have been difficult to identify. There is no consensus as to whether tumor PD-L1 expression predicts outcomes. Combination checkpoint inhibitors (CTLA4 and PD1 blockade) provide a small incremental increase in response rates and progression-free survival. Chemoimmunotherapy is the next frontier.

Patterns of care and survival of older patients with malignant pleural mesothelioma

OBJECTIVE

Malignant pleural mesothelioma (MPM) is a cancer that primarily affects older adults. However this patient population is frequently under-represented in clinical studies. Therefore, we studied the impact of advancing age on treatment utilisation and clinical outcomes in an extensive series of minimally selected MPM patients.

MATERIALS AND METHODS

Patients with MPM receiving compensation from the New South Wales (NSW) Dust Diseases Authority (2002-2009) were assessed. They were categorised by age (<70 years, 70-80 years or > 80 years) and chi-square testing was used to assess the relationship between clinical and demographic variables, age, treatment and overall survival (OS).

RESULTS

We identified 910 patients; 41% were aged <70 years, 40% were aged 70-80 years, and 19% were aged >80 years old. Median OS decreased with increasing age: 13.5 months in <70 years, 9.5 months in 70-80 years and 7.1 months in >80 years as did chemotherapy use (66%, 35% and 8% respectively). Radical surgical intervention, adjuvant, and palliative radiotherapy were less frequently used with advanced age. A Kaplan Meier analysis revealed that there was a significant survival advantage (p < .001) for patients <70 and 70-80 years receiving chemotherapy (16.8 vs 7.0 months; 13.9 vs 5.8 months respectively), but not for patients >80 years.

CONCLUSION

Advancing age group of NSW patients with MPM was associated with reduced treatment utilisation and a decline in OS. Prospective studies are warranted to verify if current treatment guidelines are relevant for the older adults with MPM.

Multimodality treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare disease of the pleura and is largely related to asbestos exposure. Despite recent advancements in technologies and a greater understanding of the disease, the prognosis of MPM remains poor; the median overall survival rate is about 6 to 9 months in untreated patients. The main therapeutic strategies for MPM are surgery, chemotherapy, and radiation therapy (RT). The two main surgical approaches for MPM are extrapleural pneumonectomy (EPP), in which the lung is removed en bloc, and pleurectomy/decortication, in which the lung stays in situ. Chemotherapy usually consists of a platinum-based chemotherapy, such as cisplatin, often combined with a folate antimetabolite, such as pemetrexed. More recently, immunotherapy has emerged as a possible therapeutic strategy for MPM. Evidence suggests that single-modality treatments are not an effective therapeutic approach for MPM. Therefore, researchers have started to explore different multimodality treatment approaches, in which often combinations of surgery, chemotherapy, immunotherapy, and RT are investigated. There is still no definitive answer to the question of which multimodality treatment combinations are most effective in improving the poor prognosis of MPM. Research into the effects of trimodality treatment approaches have found that radical approaches such as EPP and hemithoracic RT post-EPP are less effective than was previously assumed. In general, there are still a great number of unanswered questions and unknown factors regarding the ideal treatment approach for MPM. Hopefully, more research into multimodality therapy will provide insight into which combination of treatment modalities is most effective.

Inhibition of MDM2 via Nutlin-3A: A Potential Therapeutic Approach for Pleural Mesotheliomas with MDM2-Induced Inactivation of Wild-Type P53

Previously, our group demonstrated that nuclear expression of E3 ubiquitin ligase (MDM2) in malignant pleural mesothelioma (MPM) is significantly associated with decreased overall survival. A possible explanation may be that overexpression of MDM2 leads to a proteasomal degradation of TP53 that eventually results in a loss of TP53-induced apoptosis and senescence. It is well known from other tumor entities that restoration of TP53 activity, e.g., by MDM2 inhibition, results in an instant TP53-induced stress and/or DNA damage response of cancer cells. Nutlin-3A (a cis-imidazoline analogue) has been described as a potent and selective MDM2 inhibitor preventing MDM2-TP53-interaction by specific binding to the hydrophobic TP53-binding pocket of MDM2. In the present study, the effects of MDM2 inhibition in MPM via Nutlin-3A and standard platinum based chemotherapeutic agents were comparatively tested in three MPM cell lines (NCI-H2052, MSTO-211H, and NCI-H2452) showing different expression profiles of TP53, MDM2, and its physiological inhibitor of MDM2—P14/ARF. Our in vitro experiments on MPM cell lines revealed that Nutlin-3A in combination with cisplatin resulted in up to 9.75 times higher induction of senescence (p=0.0050) and up to 5 times higher apoptosis rate (p=0.0067) compared to the commonly applied cisplatin and pemetrexed regimens. Thus Nutlin-3A, a potent inhibitor of MDM2, is associated with a significant induction of senescence and apoptosis in MPM cell lines, making Nutlin-3A a promising substance for a targeted therapy in the subgroup of MPM showing MDM2 overexpression.

Immunohistochemically detectable metallothionein expression in malignant pleural mesotheliomas is strongly associated with early failure to platin-based chemotherapy

Background

Malignant pleural mesothelioma (MPM) is a biologically highly aggressive tumor arising from the pleura with a dismal prognosis. Cisplatin is the drug of choice for the treatment of MPM, and carboplatin seems to have comparable efficacy. Nevertheless, cisplatin treatment results in a response rate of merely 14% and a median survival of less than seven months. Due to their role in many cellular processes, methallothioneins (MTs) have been widely studied in various cancers. The known heavy metal detoxifying effect of MT-I and MT-II may be the reason for heavy metal drug resistance of various cancers including MPM.

Methods

105 patients were retrospectively analyzed immunohistochemically for their MT expression levels. Survival analysis was done by Cox-regression, and statistical significance determined using likelihood ratio, Wald test and Score (logrank) tests.

Results

Cox-regression analyses were done in a linear and logarithmic scale revealing a significant association between expression of MT and shortened overall survival (OS) in a linear (p=0.0009) and logarithmic scale (p=0.0003). Reduced progression free survival (PFS) was also observed for MT expressing tumors (linear: p=0.0134, log: p=0.0152).

Conclusion

Since both, overall survival and progression-free survival are negatively correlated with detectable MT expression in MPM, our results indicate a possible resistance to platin-based chemotherapy associated with MT expression upregulation, found exclusively in progressive MPM samples. Initial cell culture studies suggest promoter DNA hypomethylation and expression of miRNA-566 a direct regulator of copper transporter SLC31A1 and a putative regulator of MT1A and MT2A gene expression, to be responsible for the drug resistance.

Folic acid phenotype (FAP) is a superior biomarker predicting response to pemetrexed-based chemotherapy in malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare tumor linked to a dismal prognosis. Even the most effective chemotherapeutical regime of pemetrexed combined with cisplatin leads to a remission-rate of only about 40%. The reasons for the rather poor efficacy remain largely unknown.

RESULTS

Phenotypes were significantly associated with progression (p=0.0279) and remission (p=0.0262). Cox-regression revealed significant associations between SLC19A1/TYMS-ratio (p=0.0076) as well as FPGS/TYMS-ratio (p=0.0026) and OS. For differentiation by risk-groups, COXPH identified a strong correlation (p=0.0008).

METHODS

56 MPM specimens from patients treated with pemetrexed were used for qPCR analysis. Phenotypes and risk groups were defined by their expression levels of members of the folic acid metabolism and correlated to survival and objective response.

CONCLUSION

Our results indicate that the balance between folic acid uptake, activation and metabolism plays a crucial role in response to pemetrexed-based chemotherapy and the prognosis of MPM patients. Implementing this marker profile in MPM stratification may help to individualize MPM-therapy more efficiently.

Treatment of Malignant Pleural Mesothelioma: American Society of Clinical Oncology Clinical Practice Guideline

Purpose To provide evidence-based recommendations to practicing physicians and others on the management of malignant pleural mesothelioma. Methods ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, pathology, imaging, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2017. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 222 relevant studies to inform the evidence base for this guideline. Recommendations Evidence-based recommendations were developed for diagnosis, staging, chemotherapy, surgical cytoreduction, radiation therapy, and multimodality therapy in patients with malignant pleural mesothelioma. Additional information is available at www.asco.org/thoracic-cancer-guidelines and www.asco.org/guidelineswiki .

Chemotherapy treatment in malignant pleural mesothelioma: a difficult history

Malignant pleural mesothelioma (MPM) is a rare neoplasm that typically arises from mesothelial surfaces of the pleural cavity. Despite treatment improvements, it carries a dismal prognosis. The majority of patients either have unresectable disease or are not candidates for surgery due to medical comorbidities or old age. For such patients, chemotherapy (CT) represents the gold-standard treatment. To date, combination CT with cisplatin plus pemetrexed represents the most widely used regimen in first-line setting for patients with unresectable MPM. Other first-line options are currently available, including the use of raltitrexed instead of pemetrexed combined with platinum. In this review, we discuss the role of CT in MPM mainly focusing on the results of the trials conducted in first-line setting.

Novel systemic therapy against malignant pleural mesothelioma

Malignant pleural mesothelioma is an aggressive tumor of the pleura with an overall poor prognosis. Even with surgical resection, for which only a subset of patients are eligible, long term disease free survival is rare. Standard first-line systemic treatment consists of a platinum analog, an anti-metabolite, and sometimes anti-angiogenic therapy, but there is currently no well-established standard therapy for refractory or relapsed disease. This review focuses on efforts to develop improved systemic therapy for the treatment of malignant pleural mesothelioma (MPM) including cytotoxic systemic therapy, a variety of tyrosine kinase inhibitors and their downstream effector pathways, pharmacologic targeting of the epigenome, novel approaches to target proteins expressed on mesothelioma cells (such as mesothelin), arginine depletion therapy, and the emerging role of immunotherapy. Overall, these studies demonstrate the challenges of improving systemic therapy for MPM and highlight the need to develop therapeutic strategies to control this disease.

miRNA regulation is important for DNA damage repair and recognition in malignant pleural mesothelioma

Platin-containing regimes are currently considered as state-of-the-art therapies in malignant pleural mesotheliomas (MPM) but show dissatisfying response rates ranging from 6 to 16% only. Still, the reasons for the rather poor efficacy remain largely unknown. A clear stratification of patients based on new biomarkers seems to be a promising approach to enhance clinical management, which would be a long-needed improvement for MPM patients but does not seem likely soon unless new biomarkers can be validated. Twenty-four formalin-fixed, paraffin-embedded (FFPE) tumour specimens were subjected to a miRNA expression screening of 800 important miRNAs using digital quantification via the nCounter technique (NanoString). We defined a small subset of miRNAs regulating the key enzymes involved in the repair of platin-associated DNA damage. Particularly, the TP53 pathway network for DNA damage recognition as well as genes related to the term "BRCAness" are the main miRNA targets within this context. The TP53 pathway network for DNA damage recognition as well as genes related to the term "BRCAness" are the main players for risk stratification in patients suffering from this severe disease. Taking the specific molecular profile of the tumour into account can help to enhance the clinical management prospectively and to smooth the way to better response prediction.

microRNAs are differentially regulated between MDM2-positive and negative malignant pleural mesothelioma

Background

Malignant pleural mesothelioma (MPM) is a highly aggressive tumour first-line treated with a combination of cisplatin and pemetrexed. MDM2 and P14/ARF (CDKN2A) are upstream regulators of TP53 and may contribute to its inactivation. In the present study, we now aimed to define the impact of miRNA expression on this mechanism.

Material and Methods

24 formalin-fixed paraffin-embedded (FFPE) tumour specimens were used for miRNA expression analysis of the 800 most important miRNAs using the nCounter technique (NanoString). Significantly deregulated miRNAs were identified before a KEGG-pathway analysis was performed.

Results

17 miRNAs regulating TP53, 18 miRNAs regulating MDM2, and 11 miRNAs directly regulating CDKN2A are significantly downregulated in MDM2-expressing mesotheliomas. TP53 is downregulated in MDM2-negative tumours through miRNAs with a miSVR prediction score of 11.67, RB1 with a prediction score of 8.02, MDM2 with a prediction score of 4.50 and CDKN2A with a prediction score of 1.27.

Conclusion

MDM2 expression seems to impact miRNA expression levels in MPM. Especially, miRNAs involved in TP53-signaling are strongly decreased in MDM2-positive mesotheliomas. A better understanding of its tumour biology may open the chance for new therapeutic approaches and thereby augment patients' outcome.

Malignant pleural mesothelioma: an update on investigation, diagnosis and treatment

Malignant pleural mesothelioma is an aggressive malignancy of the pleural surface, predominantly caused by prior asbestos exposure. There is a global epidemic of malignant pleural mesothelioma underway, and incidence rates are predicted to peak in the next few years.This article summarises the epidemiology and pathogenesis of malignant pleural mesothelioma, before describing some key factors in the patient experience and outlining common symptoms. Diagnostic approaches are reviewed, including imaging techniques and the role of various biomarkers. Treatment options are summarised, including the importance of palliative care and methods of controlling pleural effusions. The evidence for chemotherapy, radiotherapy and surgery is reviewed, both in the palliative setting and in the context of trimodality treatment. An algorithm for managing malignant pleural effusion in malignant pleural mesothelioma patients is presented. Finally new treatment developments and novel therapeutic approaches are summarised.

FAS and FASL genetic polymorphisms impact on clinical outcome of malignant pleural mesothelioma

Background

FAS-670 A>G (rs1800682) and FASL-844 C>T (rs763110) polymorphisms have been previously correlated with clinical outcome of non-small cell lung cancer (NSCLC) and breast and bladder cancers. We investigated the influence of these polymorphisms on clinical outcome of malignant pleural mesothelioma (MPM) patients.

Patients and methods

In this cohort study (NCT02269878), 68 epithelioid MPM Egyptian patients treated with first-line platinum-based chemotherapy were recruited in the period between April 2014 and May 2015. The genotype analysis was performed using TaqMan^® single-nucleotide polymorphism genotyping assay. The association between the selected polymorphisms and response rate, progression-free survival (PFS) and overall survival (OS) at 18 months was evaluated.

Results

The median age of patients was 55 years and 45.6% of them received platinum in combination with pemetrexed, while 54.4% received platinum in combination with gemcitabine. FASL-844 CC genotype was more common than expected in early-stage tumor (P=0.042). It was found that there was no association between the investigated polymorphisms and response rate or 18-month OS. However, the PFS rate at 18 months for FASL-844 CC genotype carriers was 45% versus 10.6% for FASL-844 CT/TT genotypes carriers (log-rank: 6.2; P=0.013). Also, the number of platinum-based cycles and tumor stage were found to be significant variables for PFS by univariate analysis (P≤0.001 and P=0.006, respectively). Stratified Cox regression showed that the carriers of FASL-844 CT/TT genotypes were still more susceptible to disease progression than carriers of FASL-844 CC genotype (adjusted HR =3.77, 95% CI: 1.34–10.62, P=0.012).

Conclusion

The results of this study suggest that FASL-844 C/T polymorphism could predict PFS in MPM patients receiving platinum-based chemotherapy; therefore, this should be further evaluated as a potential marker for the prediction of clinical outcome in patients with MPM.

Screening of Pleural Mesotheliomas for DNA-damage Repair Players by Digital Gene Expression Analysis Can Enhance Clinical Management of Patients Receiving Platin-Based Chemotherapy

Background: Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumour leading to a dismal prognosis. Multimodality therapy consisting of platinum-based chemotherapy is the treatment of choice. The reasons for the rather poor efficacy of platinum compounds remain largely unknown.

Material and Methods: For this exploratory mRNA study, 24 FFPE tumour specimens were screened by digital gene expression analysis. Based on data from preliminary experiments and recent literature, a total of 366 mRNAs were investigated using a Custom CodeSet from NanoString. All statistical analyses were calculated with the R i386 statistical programming environment.

Results: CDC25A and PARP1 gene expression were correlated with lymph node spread, BRCA1 and TP73 expression levels with higher IMIG stage. NTHL1 and XRCC3 expression was associated with TNM stage. CHECK1 as well as XRCC2 expression levels were correlated with tumour progression in the overall cohort of patients. CDKN2A and MLH1 gene expression influenced overall survival in this collective. In the adjuvant treated cohort only, CDKN2A, CHEK1 as well as ERCC1 were significantly associated with overall survival. Furthermore, TP73 expression was associated with progression in this subgroup.

Conclusion: DNA-damage response plays a crucial role in response to platin-based chemotherapeutic regimes. In particular, CHEK1, XRCC2 and TP73 are strongly associated with tumour progression. ERCC1, MLH1, CDKN2A and most promising CHEK1 are prognostic markers for OS in MPM. TP73, CDKN2A, CHEK1 and ERCC1 seem to be also predictive markers in adjuvant treated MPMs. After a prospective validation, these markers may improve clinical and pathological practice, finally leading to a patients' benefit by an enhanced clinical management.

New therapeutic strategies for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignant disease affecting the mesothelium, commonly associated to asbestos exposure. Therapeutic actions are limited due to the late stage at which most patients are diagnosed and the intrinsic chemo-resistance of the tumor. The recommended systemic therapy for MPM is cisplatin/pemetrexed regimen with a mean overall survival of about 12months and a median progression free survival of less than 6months. Considering that the incidence of this tumor is expected to increase in the next decade and that its prognosis is poor, novel therapeutic approaches are urgently needed. For some tumors, such as lung cancer and breast cancer, druggable oncogenic alterations have been identified and targeted therapy is an important option for these patients. For MPM, clinical guidelines do not recommend biological targeted therapy, mainly because of poor target definition or inappropriate trial design. Further studies are required for a full comprehension of the molecular pathogenesis of MPM and for the development of new target agents. This review updates pre-clinical and clinical data on the efficacy of targeted therapy and immune checkpoint inhibition in the treatment of mesothelioma. Finally, future perspectives in this deadly disease are also discussed.

The Third Italian Consensus Conference for Malignant Pleural Mesothelioma: State of the art and recommendations

Malignant Pleural Mesothelioma (MPM) remains a relevant public health issue, and asbestos exposure is the most relevant risk factor. The incidence has considerably and constantly increased over the past two decades in the industrialized countries and is expected to peak in 2020-2025. In Italy, a standardized-rate incidence in 2011 among men was 3.5 and 1.25 per 100,000 in men and women, respectively, and wide differences are noted among different geographic areas. The disease remains challenging in terms of diagnosis, staging and treatment and an optimal strategy has not yet been clearly defined. The Third Italian Multidisciplinary Consensus Conference on Malignant Pleural Mesothelioma was held in Bari (Italy) in January 30-31, 2015. This Consensus has provided updated recommendations on the MPM management for health institutions, clinicians and patients.

Malignant pleural mesothelioma: an update on diagnosis and treatment options

Malignant pleural mesothelioma (MPM) represents a significant diagnostic and therapeutic challenge and is almost always a fatal disease. Imaging abnormalities are common, but have a limited role in distinguishing mesothelioma from metastatic pleural disease. Similarly, minimally invasive biomarkers have shown promise but also have limitations in the diagnosis of mesothelioma. In experienced centers, cytology and immunohistochemistry are now sufficient to diagnose the epithelioid subtype of mesothelioma, which can reduce the need for more invasive diagnostic investigations. Prognosis of MPM is modestly impacted by oncological treatments. Chemotherapy with cisplatin and pemetrexed is considered the standard of care, though the addition of bevacizumab to the platinum doublet may be the new standard of care. New targeted therapies have demonstrated some promise and are being addressed in clinical trials. This review focuses on the current data on the diagnostic and therapeutic issues of MPM.

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

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

Multimodality therapy for malignant pleural mesothelioma: surgery plus chemoradiotherapy?

Malignant pleural mesothelioma, well known for its association with asbestos exposure, is an aggressive cancer of the pleura with poor prognosis if left untreated. There is no defined standard of care, but with curative surgery-based multimodality therapy, long-term survival has been documented. In addition to radiation and/or chemotherapy, multimodality therapy includes one of two operations (extrapleural pneumonectomy or radical pleurectomy/decortication) performed with the goal of resecting all gross disease. Ongoing trials are evaluating various treatment strategies involving radical resection, chemotherapy, radiation, intracavitary chemotherapy, photodynamic therapy and immunologic/biologic agents. Improvement in early diagnosis, targeted treatment and adjuvant therapy to control micrometastatic disease are needed to improve outcomes for patients with this challenging disease.

Malignant pleural mesothelioma: new hope in the horizon with novel therapeutic strategies

Malignant pleural mesothelioma (MPM) is a rare but aggressive malignancy of the pleura, with a strong causal link to asbestos exposure. MPM incidence has been increasing in recent years and it is not expected to fall off in the next two decades. Prognosis of MPM patients is modest since the vast majority of patients are diagnosed at advanced stage and because platinum-based chemotherapy remains the cornerstone of treatment, with no standard second line treatment. Most current efforts to improve outcomes are based on a better understanding of the stromal compartment and deregulated pathways leading ultimately to the design of clinical trials based on novel therapeutic approaches such as immunotherapy or molecular-directed compounds. This review seeks to update the last clinical trials investigating novel agents in unresectable MPM.

Prognostic factors in elderly patients with malignant pleural mesothelioma: results of a multicenter survey

BACKGROUND

The incidence of malignant pleural mesothelioma (MPM) in elderly patients is increasing. There are no specific guidelines for their management.

METHODS

The clinical records of elderly patients (⩾70 years old) with MPM referred from January 2005 to November 2011 to six Italian Centres were reviewed. Age, gender, histology, International Mesothelioma Interest Group (IMIG) stage, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), Charlson Comorbidity Index (CCI) and treatment modalities were analysed and correlated to overall survival (OS).

RESULTS

In total, 241 patients were identified. Charlson Comorbidity Index was ⩾1 in 92 patients (38%). Treatment was multimodality therapy including surgery in 18, chemotherapy alone in 180 (75%) and best supportive care in 43 cases (18%). Chemotherapy was mainly pemetrexed based. Median OS was 11.4 months. Non-epithelioid histology (HR 2.32; 95% CI 1.66-3.23, P<0.001), age ⩾75 years (HR 1.44; 95% CI 1.08-1.93, P=0.014), advanced (III-IV) stage (HR 1.47; 95% CI 1.09-1.98, P=0.011) and CCI⩾1 (HR 1.38; 95% CI 1.02-1.85, P=0.034) were associated to a shorter OS. Treatment with pemetrexed was associated with improved OS (HR 0.40; 95% CI 0.28-0.56, P<0.001).

CONCLUSIONS

Non-epithelioid histology, age ⩾75 years, advanced IMIG stage and presence of comorbidities according to CCI were significant prognostic factors in elderly patients with MPM. Treatment with pemetrexed-based chemotherapy was feasible in this setting. Prospective dedicated trials in MPM elderly patients selected according to prognostic factors including comorbidity scales are warranted.