What is the survival after surgery for localized malignant pleural mesothelioma?

A Worsening Cough: An Unusual Presentation of Malignant Mesothelioma

Localized malignant pleural mesothelioma (LMPM) is a rare cancer with poor survival rates. Often affecting males with asbestos exposure, we report a case of a 56-year-old female with no history of occupational exposure presenting with a worsening cough. A radiological examination revealed left pleural effusion and pleural thickening. Cytological and pathological reports of pleural samples were consistent with malignant mesothelioma of epithelioid type, with the histological examination via video-assisted thoracoscopic surgery (VATS) consistent with a clear cell epithelioid mesothelioma. We discuss the rapid presentation of the disease with emphasis on considering the disease in young patients with no prior asbestos exposure.

Does hyperthermic povidone-iodine lavage increase the apoptotic rate of residual cancer cell in patients with malignant pleural mesothelioma?-a prospective pilot study

Background

Malignant pleural mesothelioma (MPM) is an incurable, late presenting primary cancer, conferring a survival of 8-14 months. Different intrapleural treatments have been tested as part of a multimodality approach to treat a select group of patients with limited disease, increasing survival. Recently, povidone-iodine has been shown to induce apoptosis in microscopic tumour cells in vitro, with no reported complications. This is the first in vivo study assessing the apoptotic rate caused by intraoperative hyperthermic betadine lavage using routine immunohistochemistry combined with transmission electron microscopy (TEM).

Methods

We included surgically fit patients aged >18, undergoing minimally invasive video-assisted thoracoscopic surgery (VATS) pleural biopsy between December 2016 and February 2018, for confirmed or presumed pleural malignancy. Parietal pleural biopsies were obtained at 7.5, 15 and 30 minutes after hyperthermic betadine lavage, and compared to pre-lavage biopsy samples, for apoptotic changes. Viable tumour samples underwent histological, immunohistochemical and ultrastructural analysis as well as TEM for features of apoptosis.

Results

N=6. Median age was 76 years. Median overall survival was 26.7 months. There was no statistical impact on survival of side of disease (left vs. right). There was no significant difference in expressions of markers of apoptotic index pre and post betadine treatment upon immunohistochemical analysis. There was no discernible effect on morphological features of apoptosis seen with betadine treatment, on TEM analysis. No side effects were identified post betadine lavage.

Conclusions

Although hyperthermic betadine lavage is a safe antiseptic solution with no toxicity when performed intraoperatively, it confers no effect on apoptotic rate or necrosis. It is therefore unlikely that hyperthermic betadine lavage will have an impact on reducing the microscopic residual disease after pleurectomy decortication and enhancing survival.

Localized malignant mesothelioma in the stomach and mediastinum

Localized malignant mesothelioma is rare. It has a histological pattern identical to diffuse malignant mesothelioma but without diffuse serosal spread. Localized malignant mesothelioma typically originates from the pleura, peritoneum or pericardium, but can occasionally develop from organs. Our cases represent what might be the largest mediastinal localized malignant mesothelioma described and the first presentation of the epithelioid type in the stomach of an adult.

Treatment Patterns and Outcomes of Patients With Advanced Pleural Mesothelioma at an Academic Referral Centre

BACKGROUND

Overall survival (OS) for malignant pleural mesothelioma (MPM) in vulnerable subgroups remains poorly understood with scarce data available to guide treatment decisions. The study describes real-world detailed treatment patterns and outcomes of patients with advanced MPM overall and specifically in elderly and poor performance status (PS) patients.

METHODS

Retrospective chart review was performed for all patients with histologically confirmed MPM seen at University Health Network/Princess Margaret Cancer Centre (UHN-PM).

RESULTS

A total of 667 patients with MPM were identified and 304 advanced-disease MPM (aMPM) patients had continuing care at UHN-PM (UP-cohort). In the UP-cohort, 77% of patients received ≥ one line of systemic treatment. Systemic therapy trial participation was 39%. Patients not treated with systemic therapy (29%) were more likely to be ≥ 75 years and PS ≥ 2. Median OS was 15.3 months (95%CI 13.6-18.3), with longer survival in treated vs. untreated patients (17.4 vs. 10.6 months; P = .01). Longer survival with systemic treatment was seen in patients ≥75 years (12.7 vs. 6.6 months) and patients with poor PS (9.1 vs. 5.9 months). Median progression-free-survival (PFS) and OS for patients treated with second-line therapy was poor (3.0 and 8.9 months, respectively).

DISCUSSION

In our real-world analysis of patients with aMPM treated at an academic referral centre, systemic treatment was given to the majority of patients and benefit was seen even in the elderly and poor PS patients frequently underrepresented in clinical trials. Trial participation was potentially facilitated by the formation of a dedicated multidisciplinary MPM clinic.

Application of immunohistochemistry in diagnosis and management of malignant mesothelioma

Immunohistochemistry plays an indispensable role in accurate diagnosis of malignant mesothelioma, particularly in morphologically challenging cases and in biopsy and cytology specimens, where tumor architecture is difficult or impossible to evaluate. Application of a targeted panel of mesothelial- and epithelial-specific markers permits correct identification of tumor lineage in the vast majority of cases. An immunopanel including two mesothelial markers (calretinin, CK5/6, WT-1, or D2-40) and two epithelial markers (MOC-31 and claudin-4) offers good sensitivity and specificity, with adjustments as appropriate for the differential diagnosis. Once mesothelial lineage is established, malignancy-specific studies can help verify a diagnosis of malignant mesothelioma. BAP1 loss, CDKN2A homozygous deletion, and MTAP loss are highly specific markers of malignancy in a mesothelial lesion, and they attain acceptable diagnostic sensitivity when applied as a diagnostic panel. Novel markers of malignancy, such as 5-hmC loss and increased EZH2 expression, are promising, but have not yet achieved widespread clinical adoption. Some diagnostic markers also have prognostic significance, and PD-L1 immunohistochemistry may predict tumor response to immunotherapy. Application and interpretation of these immnuomarkers should always be guided by clinical history, radiographic findings, and above all histomorphology.

Localized malignant mesothelioma, an unusual and poorly characterized neoplasm of serosal origin: best current evidence from the literature and the International Mesothelioma Panel

Localized malignant mesotheliomas (LMM) is an uncommon and poorly recognized neoplasm. Its pathologic diagnosis is often surprising in patients with serosal/subserosal based localized tumors that are clinically suspicious for metastatic lesions or primary sarcomas. Once a tumor is diagnosed as "mesothelioma", LMM is often mistaken for diffuse malignant mesothelioma (DMM). Best currently available evidence about LMM was collected from the literature and cases diagnosed by members of the International Mesothelioma Panel (IMP). One hundred and one (101) LMM have been reported in the English literature. Patients had localized tumors with identical histopathologic features to DMM. Patients ranged in age from 6 to 82 years; 75% were men. Most (82%) of the tumors were intrathoracic. Others presented as intrahepatic, mesenteric, gastric, pancreatic, umbilical, splenic, and abdominal wall lesions. Tumors varied in size from 0.6 to 15 cm. Most patients underwent surgical resection and/or chemotherapy or radiation therapy. Median survival in a subset of patients was 29 months. Seventy two additional LMM from IMP institutions ranged in age from 28 to 95 years; 58.3% were men. Sixty tumors (83.3%) were intrathoracic, others presented in intraabdominal sites. Tumors varied in size from 1.2 to 19 cm. Median survival for 51 cases was 134 months. Best evidence was used to formulate guidelines for the diagnosis of LMM. It is important to distinguish LMM from DMM as their treatment and prognosis is different. A multidisciplinary approach is needed for the diagnosis of LMM as it shows identical histopathology and immunophenotype to DMM.

Thoracic aortic endografts used to resect the left subclavian artery infiltrated by malignant tumours

Endograft placement is a minimally invasive procedure used to repair thoracic aortic aneurysms. This technique is used for treating aneurysms and aortic dissections or ruptures, but it can also be applied for the resection of malignant tumours with vascular invasion. We describe the successful use of the thoracic endovascular aortic repair technique to remove a malignant tumour infiltrating the left subclavian artery in a 50-year-old man. The resection of the left subclavian artery infiltrated by thoracic malignant tumours may require temporary cardiopulmonary bypass, direct clamping of the aorta or extracorporeal circulation techniques. However, the off-label use of thoracic endovascular aortic repair avoids the need for these high-risk surgical techniques. After the surgical removal of the mass and combined aortic resection without complications, the patient was eligible to undergo chemotherapy/radiotherapy, thus improving his prognosis.

Localized malignant pleural mesothelioma mimicking an anterior mediastinal tumor

Localized malignant pleural mesothelioma (LMPM) is an extremely rare tumor. We report the case of a 40-year-old Japanese male with an LMPM mimicking an anterior mediastinal tumor due to invasion to the anterior mediastinum, and we discuss mainly the differentiation of LMPM from an anterior mediastinal tumor. The present tumor had a long shape along the pleura, and LMPM could be one of the differential diagnoses.

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 .

Proteasome stress sensitizes malignant pleural mesothelioma cells to bortezomib-induced apoptosis

Based on promising results in preclinical models, clinical trials have been performed to evaluate the efficacy of the first-in-class proteasome inhibitor bortezomib towards malignant pleural mesothelioma (MPM), an aggressive cancer arising from the mesothelium of the serous cavities following exposure to asbestos. Unexpectedly, only minimal therapeutic benefits were observed, thus implicating that MPM harbors inherent resistance mechanisms. Identifying the molecular bases of this primary resistance is crucial to develop novel pharmacologic strategies aimed at increasing the vulnerability of MPM to bortezomib. Therefore, we assessed a panel of four human MPM lines with different sensitivity to bortezomib, for functional proteasome activity and levels of free and polymerized ubiquitin. We found that highly sensitive MPM lines display lower proteasome activity than more bortezomib-resistant clones, suggesting that reduced proteasomal capacity might contribute to the intrinsic susceptibility of mesothelioma cells to proteasome inhibitors-induced apoptosis. Moreover, MPM equipped with fewer active proteasomes accumulated polyubiquitinated proteins, at the expense of free ubiquitin, a condition known as proteasome stress, which lowers the cellular apoptotic threshold and sensitizes mesothelioma cells to bortezomib-induced toxicity as shown herein. Taken together, our data suggest that an unfavorable load-versus-capacity balance represents a critical determinant of primary apoptotic sensitivity to bortezomib in MPM.

Bevacizumab for newly diagnosed pleural mesothelioma in the Mesothelioma Avastin Cisplatin Pemetrexed Study (MAPS): a randomised, controlled, open-label, phase 3 trial

BACKGROUND

Malignant pleural mesothelioma is an aggressive cancer with poor prognosis, linked to occupational asbestos exposure. Vascular endothelial growth factor is a key mitogen for malignant pleural mesothelioma cells, therefore targeting of vascular endothelial growth factor might prove effective. We aimed to assess the effect on survival of bevacizumab when added to the present standard of care, cisplatin plus pemetrexed, as first-line treatment of advanced malignant pleural mesothelioma.

METHODS

In this randomised, controlled, open-label, phase 3 trial, we recruited patients aged 18-75 years with unresectable malignant pleural mesothelioma who had not received previous chemotherapy, had an Eastern Cooperative Oncology Group performance status of 0-2, had no substantial cardiovascular comorbidity, were not amenable to curative surgery, had at least one evaluable (pleural effusion) or measurable (pleural tumour solid thickening) lesion with CT, and a life expectancy of >12 weeks from 73 hospitals in France. Exclusion criteria were presence of central nervous system metastases, use of antiaggregant treatments (aspirin ≥325 mg per day, clopidogrel, ticlopidine, or dipyridamole), anti-vitamin K drugs at a curative dose, treatment with low-molecular-weight heparin at a curative dose, and treatment with non-steroidal anti-inflammatory drugs. We randomly allocated patients (1:1; minimisation method used [random factor of 0·8]; patients stratified by histology [epithelioid vs sarcomatoid or mixed histology subtypes], performance status score [0-1 vs 2], study centre, or smoking status [never smokers vs smokers]) to receive intravenously 500 mg/m(2) pemetrexed plus 75 mg/m(2) cisplatin with (PCB) or without (PC) 15 mg/kg bevacizumab in 21 day cycles for up to six cycles, until progression or toxic effects. The primary outcome was overall survival (OS) in the intention-to treat population. Treatment was open label. This IFCT-GFPC-0701 trial is registered with ClinicalTrials.gov, number NCT00651456.

FINDINGS

From Feb 13, 2008, to Jan 5, 2014, we randomly assigned 448 patients to treatment (223 [50%] to PCB and 225 [50%] to PC). OS was significantly longer with PCB (median 18·8 months [95% CI 15·9-22·6]) than with PC (16·1 months [14·0-17·9]; hazard ratio 0·77 [0·62-0·95]; p=0·0167). Overall, 158 (71%) of 222 patients given PCB and 139 (62%) of 224 patients given PC had grade 3-4 adverse events. We noted more grade 3 or higher hypertension (51 [23%] of 222 vs 0) and thrombotic events (13 [6%] of 222 vs 2 [1%] of 224) with PCB than with PC.

INTERPRETATION

Addition of bevacizumab to pemetrexed plus cisplatin significantly improved OS in malignant pleural mesothelioma at the cost of expected manageable toxic effects, therefore it should be considered as a suitable treatment for the disease.

FUNDING

Intergroupe Francophone de Cancérologie Thoracique (IFCT).

Localized malignant pleural mesothelioma with renal metastasis

Localized malignant pleural mesothelioma (LMM) is a rare subset of malignant pleural mesothelioma. Its epidemiology, biology, natural history and optimal treatment are poorly understood. We report a case of LMM treated aggressively with complete surgical resection and adjuvant radiotherapy, but subsequently complicated by local chest wall recurrence and solitary metastasis to the kidney. This case is examined in the context of a small number of cases of LMM in the literature to emphasize the existence of this rare disease entity, their unusual biological behaviour and the need for further tumour molecular and genomic research.

Microcystic variant malignant mesothelioma presenting as a localized paraspinal mass

A 58-year-old man presented with productive cough and fever. Computed tomography (CT) scan of the chest showed an upper right paraspinal mass. CT-guided fine-needle aspiration biopsy showed lobules of vacuolated cells against a background of myxoid material. The cells demonstrated moderate to severe nuclear atypia and occasional mitoses. Immunohistochemistry revealed tumor cells to be immunoreactive for calretinin, WT-1, D2-40, cytokeratin (CK) 7, AE1/AE3, high molecular weight keratin, vimentin and epithelial membrane antigen, and negative for thyroid transcription factor-1, Ber-EP4, carcinoembryonic antigen, S100 protein, CK20, and CDX2. The combined morphologic and immunohistochemical findings confirmed the diagnosis of microcystic variant of localized malignant mesothelioma. The subsequent lung resection showed a pleural-based mass in the right upper lobe and confirmed the diagnosis. Awareness of the existence of unusual morphologic variants and localized forms of mesothelioma are necessary to avoid misdiagnosis of fine needle biopsy samples. Recognition of characteristic cytomorphologic features along with optimal use of panel of immunohistochemistry studies is crucial for making a specific diagnosis.