Surgical treatment of malignant pleural mesothelioma: a review

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.

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.

Post-Pleuropneumonectomy Herniation of Liver Mimicking Major Pulmonary Embolism

Following right-sided pneumonectomy and hemidiaphragm resection in a 58-year-old man with epithelioid mesothelioma, acute respiratory insufficiency and life-threatening circulatory collapse developed after a forced Valsalva maneuver. Major pulmonary embolism was diagnosed on clinical grounds, however computed tomography revealed herniation of the liver into the right hemithorax.

Combination effect of photodynamic therapy using NPe6 with pemetrexed for human malignant pleural mesothelioma cells

To identify a possible new treatment modality for malignant pleural mesothelioma (MPM), we examined whether combination treatment consisting of pemetrexed chemotherapy and photodynamic therapy (PDT) using the photosensitizer NPe6, enhanced the antitumor effect in both in vitro and in vivo models. We also investigated preclinical treatment schedules. Four human malignant mesothelioma cell lines (MSTO‑211H, H2052, H2452 and H28) were assayed using the WST assay after treatment with pemetrexed and NPe6‑PDT. The treatment schedule for the combination treatment was examined using nude mice. Pemetrexed pre‑treatment enhanced the lethal effect of NPe6‑PDT in the four malignant mesothelioma cell lines, but NPe6‑PDT followed by pemetrexed treatment did not enhance cell lethality in the in vitro assay. Pemetrexed pre‑treatment did not enhance the intracellular accumulation of NPe6, which is one of the determinants of the antitumor effect of PDT. In nude mice injected with MSTO‑211H cells and then treated using a combination of pemetrexed and NPe6‑PDT (10 mg/kg NPe6, 10 J/cm(2) laser irradiation), the tumor volume decreased by 50% but subsequently increased, reaching the pre‑treatment value after 14 days. Pemetrexed treatment followed by NPe6‑PDT resulted in an 80% reduction in the tumor size and inhibited re‑growth. NPe6‑PDT followed by pemetrexed treatment resulted in a 60% reduction in tumor size but did not inhibit re‑growth. NPe6‑PDT induced the expression of thymidylate synthase (TS), which confers resistance to pemetrexed, and NPe6‑PDT followed by pemetrexed treatment did not enhance the treatment outcome in vivo. In conclusion, combination treatment, consisting of pemetrexed followed by NPe6‑PDT, should be further investigated as a new treatment modality for MPM. In the future, this combination treatment may contribute to a reduction in local recurrence and a prolonged survival period in patients with MPM.

Malignant pleural mesothelioma: a single-center experience in Turkey

BACKGROUND

Malignant pleural mesothelioma is a rare lethal malignancy caused by asbestos exposure. It is more frequently seen in certain regions in Turkey. In this retrospective study, we aimed to analyse demographic, clinical, and pathological data and treatment-related features in 54 patients.

MATERIAL AND METHODS

The study included 54 patients diagnosed with malignant mesothelioma that were followed and treated.

RESULT

Of the 54 patients, 34 (55.6%) were male. The median age in men and women were 60.3 (38.2-77.2) and 65.8 (37.7-77.5) years, respectively. In 35 (64.8%), exposure to asbestosis was present. Epithelial type was found in 27 (50.0%), followed by mixed type in 7 (13.0%) patients, and in 20 (37.0%) patients the subtype could not be determined. The disease was staged as IV in 37 (68.5%) patients. In 28 patients (51.9%), it was right-sided and in 1 (1.9%) it was bilateral. The most frequent metastatic sites (in decreasing order) were lungs, mediastinum, diaphragm, liver, and thoracal wall. Of the 54 patients, 36 (66.6%) received 1st-line chemotherapy and 20 (37%) 2nd-line chemotherapy. Eighteen patients (33.3%) received radiotherapy; 11 (20.3%) with palliative intention and 7 (12.9%) with curative intention. Median overall survival (OS) was 12.03 months (95% CI 7.2-16.8). OS was not affected by sex (p=0.32), smoking history (p=0.51), alcohol consumption (p=0.36), family history (p=0.67), pleural effusion presence (p=0.80), operation (p=0.14), clinical stage (p=0.072), symptom at presentation (p=0.66), having mixed type histology (p=0.079), asbestos exposure (p=0.06), and type of 1st-line chemotherapy (p=0.161). On the contrary, it may be positively affected by good ECOG PS (0-1) (p<0.01), age below 65 (p=0.03), left-sided disease (p=0.01), receiving chemotherapy (p<0.01), having unilateral pleural effusion (p=0.018), and type of 2nd-line chemotherapy (p=0.025).

CONCLUSIONS

OS of our patients was better than that found in the literature, seeming to be positively affected by early stages, better ECOG PS, age below 65 years, left side involvement, and having second-line chemotherapy with cisplatin-gemcitabine or 3M. Overall treatment success seems to be comparable to what is currently expected.

Is galectin-3 antibody a useful marker in the diagnosis of malignant pleural mesothelioma?

Malignant pleural mesothelioma (MPM) is a challenging diagnosis characterized by the absence of real specific diagnostic markers. Positivity with the galectin-3 antibody was assessed by a cytoplasmic expression in 17 MPM. Fourteen cases expressed the galectin-3 antibody. The three negative cases consisted of epithelioid, biphasic, and sarcomatoid MPM. The 14 positive cases consisted of epithelioid MPM in 12 cases, sarcomatoid MPM in one case, and biphasic MPM in one case. In spite of our inability to prove the real diagnostic value of the galectin-3 antibody, our findings make us wonder about the implication of this antibody in the carcinogenesis of MPM.

Role of new radiation techniques in the treatment of pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm arising from the surface serosal cells of the pleural cavity. Surgery remains the main therapeutic standard in the treatment of MPM with the goal of complete gross cytoreduction of the tumor. Because MPM is a diffuse disease affecting the entire mesothelial lining of the hemithorax, surgery alone can rarely achieve adequate tumor-free resection margins. The surgical choices are pleurectomy/decortication (P/D) or extrapleural pneumonectomy (EPP). Radiotherapy (RT) is usually applied postoperatively with the aim to improve local control. However, the efficacy of RT is limited by the large volume of the target to be irradiated (tumor and pleural cavity) and the radiosensitivity of the nearby organs (heart, liver, lung, spinal cord, and esophagus). These factors have historically limited the effective radiation doses that can be given to the patient. There is no role for radical RT alone, but the role of RT as part of multimodality therapy is discussed. After EPP adjuvant RT to the entire hemithorax can reduce the recurrence rate and is well tolerated if strict limits to the dose to contralateral lung are applied: the V20 and V5 (the percent volume of the lung receiving more than 20Gy and 5Gy of radiation) correlate with increased lung toxicity. The use of modern sophisticated techniques allows good target coverage, more conformal high dose delivery, and clinically relevant normal tissue sparing.

Clinical characteristics, treatment and survival outcomes in malignant mesothelioma: eighteen years' experience in Turkey

BACKGROUND

Malignant mesothelioma (MM) is an insidious tumor with poor prognosis, arising from mesothelial surfaces such as pleura, peritoneum and pericardium. We here aimed to evaluate the demographic, clinical, and radiological features of patients with MM followed in our center as well as their survival.

METHODS

The study included 228 patients (131 male, 97 female) who were followed up in our institution between 1993 and 2010 with the diagnosis of MM.

RESULTS

The mean age was 59.1 years in men and 58.7 years in women and the sex ratio was 1.4:1 in favor of males. Environmental asbestos exposure was present in 86% of the patients for a mean duration of 40±20 years (range: 3-70). Pleural effusion and thoracic/abdominal pain were the most common presenting signs and symptoms (70.2% and 57.8%, respectively). One hundred-thirteen (66%) patients were treated with platinum-based combination chemotherapy (PBCT) plus supportive care (SC) and 67 (34%) patients received SC alone. The median follow-up time was 10.0 months. The median overall survival was significantly improved with PBCT plus SC compared to SC alone (11.4 vs. 5.1 months; p=0.005). The 6, 12, 18, and 24-month survival rates were significantly improved with PBCT plus SC compared to SC alone (72%, 43%, 19%, and 2% vs. 49%, 31%, 11%, and 1%).

CONCLUSION

The survival of patients with MM improved in patients treated with PBCT. The survival advantage continued 12- and 24-month after the initial time of combination chemotherapy.

Prediction of lung tumor types based on protein attributes by machine learning algorithms

Early diagnosis of lung cancers and distinction between the tumor types (Small Cell Lung Cancer (SCLC) and Non-Small Cell Lung Cancer (NSCLC) are very important to increase the survival rate of patients. Herein, we propose a diagnostic system based on sequence-derived structural and physicochemical attributes of proteins that involved in both types of tumors via feature extraction, feature selection and prediction models. 1497 proteins attributes computed and important features selected by 12 attribute weighting models and finally machine learning models consist of seven SVM models, three ANN models and two NB models applied on original database and newly created ones from attribute weighting models; models accuracies calculated through 10-fold cross and wrapper validation (just for SVM algorithms). In line with our previous findings, dipeptide composition, autocorrelation and distribution descriptor were the most important protein features selected by bioinformatics tools. The algorithms performances in lung cancer tumor type prediction increased when they applied on datasets created by attribute weighting models rather than original dataset. Wrapper-Validation performed better than X-Validation; the best cancer type prediction resulted from SVM and SVM Linear models (82%). The best accuracy of ANN gained when Neural Net model applied on SVM dataset (88%). This is the first report suggesting that the combination of protein features and attribute weighting models with machine learning algorithms can be effectively used to predict the type of lung cancer tumors (SCLC and NSCLC).

Malignant pleural mesothelioma: update on treatment options with a focus on novel therapies

There is evidence that improved treatments of malignant pleural mesothelioma are increasing the quality and quantity of life for patients with mesothelioma. Multimodality treatment programs that combine maximal surgical cytoreduction with novel forms of radiation therapy and more effective chemotherapy combinations may offer significant increases in survival for certain subgroups of patients with mesothelioma. Lung-sparing surgery may allow improvements in pulmonary function after surgery-based multimodality therapy, and potential longer overall survival than that seen with extrapleural pneumonectomy. Experimental treatments provide hope for all patients with mesothelioma, and in the future may be combined with standard therapy in multimodality protocols.

The evolution of multimodality therapy for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare neoplasm of the pleural surfaces that has been associated with asbestos exposure. MPM generally spreads locally along the ipsilateral pleura, especially at presentation, with distant metastatic disease typically seen only in the later stages of the disease course. As such, surgical resection and other local therapies have long been pursued as a primary form of treatment. Surgical options include debulking of the pleura by pleurectomy/decortication (P/D) or a more aggressive extrapleural pneumonectomy (EPP) which also involves removal of the lung, diaphragm, and involved pericardium. Even after major resection, MPM almost always recurs locally and has a poor prognosis. As such, many groups have pursued multimodality therapy, treating resectable patients with EPP, along with hemithoracic radiation to decrease the risk of local recurrence and chemotherapy to decrease the risk of distant metastatic disease. However, EPP is associated with significant morbidity and mortality, and many patients are not candidates for EPP due to underlying comorbid medical conditions. Additionally, many patients are unable to tolerate complete courses of adjuvant therapy after EPP. A large, multicenter retrospective analysis comparing EPP to P/D demonstrated better outcomes among those who underwent P/D. One challenge associated with P/D has been the delivery or radiation to the removed pleura with an intact lung. Yet, advances in radiation technique have allowed the exploration of high-dose radiation therapy after P/D. The ideal timing of chemotherapy relative to surgery and the role of intracavitary chemotherapy continue to be controversial issues. Clearly, MPM requires a multidisciplinary approach and, due to the myriad of open questions, much effort continues to focus on identifying the optimal combination of surgery, chemotherapy, and radiation.

Quantitative measurement of lung reexpansion in malignant pleural mesothelioma patients undergoing pleurectomy/decortication

RATIONALE AND OBJECTIVES

Malignant pleural mesothelioma (MPM) is a neoplasm that grows circumferentially along the pleura. The tumor and concurrent pleural effusion may reduce lung function by restricting or preventing lung expansion. The purpose of this study was to provide objective evidence that pleurectomy/decortication (P/D) allows trapped lung to reexpand, quantify the reexpansion based on computed tomography (CT) scans, and investigate whether the expansion persists after surgery.

MATERIALS AND METHODS

A database of 12 patients demonstrating unilateral MPM was collected. Each patient underwent a presurgical CT scan, surgical debulking by P/D, and two postsurgical CT scans (at 1 and 4 months). The lung volume was measured in each scan using an automated algorithm and compared for each patient across time.

RESULTS

An increase in the ipsilateral postsurgical lung volume was observed for 10 of 12 patients (83%) 1 month after surgery. The median ipsilateral volume increase was 44% relative to the presurgical ipsilateral volume and 21% relative to the contralateral volume. A statistically significant change in ipsilateral lung volume was not observed between 1‑month and 4‑month postsurgical scans, implying that the volume improvement persisted months after surgery.

CONCLUSIONS

Debulking of MPM with P/D substantially increased the ipsilateral lung volume relative to both the presurgical ipsilateral volume and the contralateral lung volume. This improvement persisted months after surgery.

Malignant mesothelioma: a clinical study of 238 cases

Malignant mesothelioma is a diffuse tumor arising in the pleura, peritoneum, or other serosal surface and is closely associated with asbestos exposure. An estimated 2,500 to 3,000 cases are diagnosed each year in the United States. Although there are individual case reports and small series detailing the clinical aspects of mesothelioma, few studies examine a large series of patients with malignant mesothelioma from the clinical perspective. This study reports on the findings of 238 cases of malignant mesothelioma from a private consultative medical practice. Most cases had a history of occupational asbestos exposure. The mean latency was 48.5 yr, with women having a longer latency than men. The mean age at diagnosis was 70. Survival overall was poor (mean 8.8 months), but treatment was beneficial (mean 11.3 versus 6.4 months). Epithelioid histology conferred a survival advantage over sarcomatoid and responded better to treatment. Our data support an inverse relationship between asbestos dose and latency.

Second surgery for recurrence of malignant pleural mesothelioma after extrapleural pneumonectomy

BACKGROUND

Extrapleural pneumonectomy is a treatment option for malignant pleural mesothelioma (MPM), but disease recurrence is common. Among different therapeutic options for recurrence, we have found no reports for second surgical procedures.

METHODS

We retrospectively evaluated the types and outcomes of surgical management of solid recurrences of MPM, in a series of 74 patients treated with extrapleural pneumonectomy over a 20-year period.

RESULTS

Of 57 patients for whom follow-up data were available, 11 patients experienced recurrent disease in the form of a solid mass, 1.5 to 12 years after the initial treatment; 8 of these patients had sufficiently good clinical conditions to undergo a second surgery with curative intent. Chest wall resection was performed in 4 cases of parietal recurrence, radical retroperitoneal resection was done in 3 cases of retroperitoneal relapse, and segmental resection of the remaining lung was done in one case of pulmonary metastasis. In this latter case, although computed tomographic images showed a solid mass, at surgery the disease was found to have a serosal nature, precluding the possibility of a curative surgery. Median survival after the second surgery was 14.5 months (range, 6 to 29); no association between survival and site of recurrence, age or disease-free interval was found.

CONCLUSIONS

In this series, the second surgery did not offer the expected survival benefit of curative treatment strategies and should therefore be considered palliative. Second surgery may be a treatment option in a subset of patients who experience a solid recurrence of MPM that is symptomatic or near vital organs and who cannot undergo additional radiotherapy.

[Thoracic surgery: the major surgical procedures]

The most frequent thoracic surgeries are performed for the treatment of primary lung cancer and pleural mesothelioma. For lung cancer, the standard procedures are pneumonectomy and lobectomy with associated mediastinal lymphadenectomy. In order to avoid pneumonectomy, extended lobectomy with sleeve bronchoplasty and/or angioplasty can be done. When adjacent organs are involved, extended resections are accepted (chest wall, vena cava...). For small lesions (<2 cm) without lymph nodes involvement and for patients with limited respiratory function, segmentectomy is an option (results under evaluation). For the treatment of pleural mesothelioma, the accepted oncologic resection is extra-pleural pneumonectomy extended to the diaphragm and pericardium. This surgical indication requires careful evaluation of tumour staging and patient's capacities. The morbidity and mortality of these resections require comprehensive follow-up (clinical, biological (including blood gases) and radiological).

Multicenter phase II trial of neoadjuvant pemetrexed plus cisplatin followed by extrapleural pneumonectomy and radiation for malignant pleural mesothelioma

PURPOSE

Neoadjuvant pemetrexed plus cisplatin was administered, followed by extrapleural pneumonectomy (EPP) and hemithoracic radiation (RT), to assess the feasibility and efficacy of trimodality therapy in stage I to III malignant pleural mesothelioma.

PATIENTS AND METHODS

Requirements included stage T1-3 N0-2 disease, no prior surgical resection, adequate organ function (including predicted postoperative forced expiratory volume in 1 second > or = 35%), and performance status 0 to 1. Patients received pemetrexed 500 mg/m(2) plus cisplatin 75 mg/m(2) for four cycles. Patients without disease progression underwent EPP followed by RT (54 Gy). The primary end point was pathologic complete response (pCR) rate.

RESULTS

Seventy-seven patients received chemotherapy. All four cycles were administered to 83% of patients. The radiologic response rate was 32.5% (95% CI, 22.2 to 44.1). Fifty-seven patients proceeded to EPP, which was completed in 54 patients. Three pCRs were observed (5% of EPP). Forty of 44 patients completed irradiation. Median survival in the overall population was 16.8 months (95% CI, 13.6 to 23.2 months; censorship, 33.8%). Patients completing all therapy had a median survival of 29.1 months and a 2-year survival rate of 61.2%. Radiologic response of complete or partial response was associated with a median survival of 26.0 months compared with 13.9 months for patients with stable disease or progressive disease (P = .05).

CONCLUSION

This multicenter trial showed that trimodality therapy with neoadjuvant pemetrexed plus cisplatin is feasible with a reasonable long-term survival rate, particularly for patients who completed all therapy. Radiologic response to chemotherapy, but not sex, histology, disease stage, or nodal status, was associated with improved survival.

New diagnostic and molecular characteristics of malignant mesothelioma

Malignant mesothelioma is a primary cancer of the serosal cavities, an anatomic site that is also frequently affected by metastatic disease, predominantly from primary carcinomas of the lung, breast, and ovary. Advances in immunohistochemistry have resulted in improved diagnostic sensitivity and specificity in the differential diagnosis between metastatic adenocarcinoma and malignant mesothelioma in both cytological and histological material. Recently, the author's group applied high throughput technology to the identification of new markers that may aid in differentiating malignant mesothelioma from ovarian and peritoneal serous carcinoma, tumors with closely related histogenesis and antigenic profile. In addition to the improved tools available for serosal cancer diagnosis, knowledge regarding the biology of malignant mesothelioma has been accumulating in recent years. This review presents current data regarding the diagnostic and biological aspects of malignant mesothelioma.

Problems in mesothelioma diagnosis

Many centres are now seeing increasing numbers of patients with malignant mesothelioma. This presents pathologists involved in making the diagnosis with a number of problems, which can be divided into those encountered in making the distinction between mesothelioma and benign changes and those experienced in separating mesotheliomas from other types of epithelial and connective tissue tumours. Immunohistochemistry plays a major role in helping to make the diagnosis, but it should be interpreted with due regard to the clinical setting and radiological features, and with a knowledge of the wide morphological variations seen in mesothelioma. This review identifies some of these problems and addresses the uses and limitations of immunohistochemistry in different situations. It includes a discussion of some of the less common variants of mesothelioma and other pleural-based tumours that enter into the differential diagnosis.

Single-agent pemetrexed for chemonaïve and pretreated patients with malignant pleural mesothelioma: results of an International Expanded Access Program

INTRODUCTION

Pemetrexed has established efficacy, and is the backbone for chemotherapy in patients with malignant pleural mesothelioma (MPM). An International Expanded Access Program provided >3000 mesothelioma patients with access to single-agent pemetrexed or pemetrexed plus platinum analogs (cisplatin or carboplatin) in 13 countries. In this article, we report the safety and efficacy data of MPM patients who were treated with single-agent pemetrexed (n = 812).

METHODS

Patients with histologically confirmed MPM, not amenable to curative surgery, received pemetrexed (500 mg/m) once (day 1) every 21 days with standard premedication and vitamin supplementation. Investigator-determined response and survival data were recorded at the end of study participation. Myelosuppression data were also collected.

RESULTS

All 812 MPM patients (319 chemonaïve; 493 pretreated) received single-agent pemetrexed (>or=1 dose) and were evaluated for safety. A total of 643 patients (247 chemonaïve, 396 pretreated) were evaluated for efficacy. Of the chemonaïve patients evaluated for efficacy (n = 247), the overall response rate was 10.5%, median time to progressive disease (TTPD) was 6.0 months, and median survival was 14.1 month. Of the pretreated patients evaluated for efficacy (n = 396), the overall response rate was 12.1%, median TTPD was 4.9 months, and the median survival was not estimable due to high censoring. Common terminology criteria grade 3/4 hematologic toxicity was mild in both groups, with neutropenia (<18%) as the main toxicity.

CONCLUSIONS

In the present expanded access program, single-agent pemetrexed demonstrated promising activity in MPM in both chemonaïve and pretreated patients, with TTPD of 6.0 and 4.9 months, respectively, 1-year survival >or=54.7%, and mild hematologic toxicity.

Malignant mesothelioma: current status and perspective in Japan and the world

Malignant pleural mesothelioma (MPM) is associated with a poor prognosis; and to make things worse, its incidence is increasing throughout the world. Surgical management of MPM is comprised of two aspects: diagnosis and resection. Surgical biopsy with thoracoscopy provides a higher yield but a higher rate of tumor cell seeding than blind biopsy. In some surgical cases, extended surgical staging with mediastinoscopy, laparoscopy, and contralateral thoracoscopy is required for the preoperative evaluation for resectablity. There are two types of surgical resection for MPM. Pleurectomy/decortication (P/D) involves removal of as much of the visceral, parietal, and pericardial pleura and the tumor as possible without removing the underlying lung. Because P/D is less radical but less invasive compared to extrapleural pneumonectomy (EPP), it can be tolerated by poor-risk patients. EPP comprises en bloc resection of visceral, parietal, and pericardial pleura and adjacent components such as ipsilateral lung, pericardium, and diaphragm, without opening the pleural cavity. EPP was considered a highly dangerous procedure with a surgical mortality of more than 30% decades ago, but its current operative mortality/morbidity rates are 4%-9% and 60%, respectively. As macroscopic complete resection is the primary goal of surgery for MPM because of its diffuse intrapleural growth, surgical resection alone is associated with poor survival. In this context, combination therapy with surgery plus chemotherapy and/or radiotherapy is currently considered the standard treatment for patients with respectable MPM. A national survey of EPP was conducted recently in Japan, and a few multicenter clinical trials will start soon.

Phase II trial of pemetrexed and gemcitabine in chemotherapy-naive malignant pleural mesothelioma

PURPOSE

Pemetrexed and gemcitabine have single-agent activity in malignant pleural mesothelioma (MPM). The combination of pemetrexed/gemcitabine has not previously been studied in MPM to our knowledge.

PATIENTS AND METHODS

Patients with histologic or cytologic diagnosis of MPM were included. Cohort 1 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 8, and cohort 2 received gemcitabine 1,250 mg/m(2) on days 1 and 8, with pemetrexed 500 mg/m(2) on day 1. Cycles were repeated every 21 days; all patients were supplemented with folic acid and vitamin B(12) and received dexamethasone.

RESULTS

One hundred eight patients (cohort 1, n = 56; cohort 2, n = 52) with pleural mesothelioma were enrolled. Among assessable patients, response rate was 26.0% in cohort 1 and 17.1% in cohort 2. Median time to disease progression was 4.34 months for cohort 1 and 7.43 months for cohort 2. Median survival was 8.08 months for cohort 1 (1-year survival = 31.14%) and 10.12 months for cohort 2 (1-year survival = 45.80%). In cohorts 1 and 2, incidence of grade 4 neutropenia was 25.0% and 29.4%, grade 4 thrombocytopenia was 14.3% and 3.9%, grade 3 or 4 anemia was 5.4% and 5.9%, and grade 3 or 4 fatigue was 23.2% and 15.7%, respectively.

CONCLUSION

The combination of pemetrexed and gemcitabine resulted in moderate clinical activity in MPM. However, the median survival times are similar to those with single-agent pemetrexed and inferior to outcomes observed with cisplatin in combination with an antifolate.

[Malignant pleural mesothelioma: multidisciplinary experience in a public tertiary hospital]

OBJECTIVE

To evaluate the experience in diagnosing and treating malignant pleural mesothelioma (MPM) accumulated over 5 years in a tertiary public hospital.

METHODS

The medical charts of the patients diagnosed with MPM between January of 2000 and February of 2005 were evaluated retrospectively.

RESULTS

Of the 17 patients analyzed, 14 were male and 3 were female. The mean age was 54.1 years (range, 13-75 years). The biopsy specimens for histopathological examination were obtained through thoracoscopy in 9 patients (53%), Cope needle in 5 (29.5%), and open pleural biopsy in 3 (17.5%). The following histological types were identified: epithelial, in 14 patients (82%); sarcomatoid, in 1 (6%); and biphasic, in 2 (12%). The therapeutic approaches used were as follows: multimodal (pleuropneumonectomy and adjuvant radiotherapy and chemotherapy) in 6 patients (35%); chemotherapy and radiotherapy in 6 (35%); radiotherapy alone in 3 (17.5%); and chemotherapy alone in 2 (12%). The mean survival was 11 months (range, 1-26 months).

CONCLUSIONS

In the cases studied, an integrated multidisciplinary approach was used, and a highly complex hospital infrastructure was available for the diagnosis and treatment of MPM, as recommended in the literature. However, the mean survival was only 11 months, reflecting the aggressiveness of the disease.

Intensity-modulated radiotherapy for resected mesothelioma: the Duke experience

PURPOSE

To assess the safety and efficacy of intensity-modulated radiotherapy (IMRT) after extrapleural pneumonectomy for malignant pleural mesothelioma.

METHODS AND MATERIALS

Thirteen patients underwent IMRT after extrapleural pneumonectomy between July 2005 and February 2007 at Duke University Medical Center. The clinical target volume was defined as the entire ipsilateral hemithorax, chest wall incisions, including drain sites, and involved nodal stations. The dose prescribed to the planning target volume was 40-55 Gy (median, 45). Toxicity was graded using the modified Common Toxicity Criteria, and the lung dosimetric parameters from the subgroups with and without pneumonitis were compared. Local control and survival were assessed.

RESULTS

The median follow-up after IMRT was 9.5 months. Of the 13 patients, 3 (23%) developed Grade 2 or greater acute pulmonary toxicity (during or within 30 days of IMRT). The median dosimetric parameters for those with and without symptomatic pneumonitis were a mean lung dose (MLD) of 7.9 vs. 7.5 Gy (p = 0.40), percentage of lung volume receiving 20 Gy (V(20)) of 0.2% vs. 2.3% (p = 0.51), and percentage of lung volume receiving 5 Gy (V(20)) of 92% vs. 66% (p = 0.36). One patient died of fatal pulmonary toxicity. This patient received a greater MLD (11.4 vs. 7.6 Gy) and had a greater V(20) (6.9% vs. 1.9%), and V(5) (92% vs. 66%) compared with the median of those without fatal pulmonary toxicity. Local and/or distant failure occurred in 6 patients (46%), and 6 patients (46%) were alive without evidence of recurrence at last follow-up.

CONCLUSIONS

With limited follow-up, 45-Gy IMRT provides reasonable local control for mesothelioma after extrapleural pneumonectomy. However, treatment-related pulmonary toxicity remains a significant concern. Care should be taken to minimize the dose to the remaining lung to achieve an acceptable therapeutic ratio.

Management options for malignant pleural mesothelioma: clinical and cost considerations

Malignant pleural mesothelioma (MPM) is a resistant form of lung cancer that is often related to prior asbestos exposure. While surgical resection and radiotherapy techniques have been refined in recent years, neither has been proven to significantly extend patient survival compared with untreated controls. Until the release of pemetrexed in 2004, even combination chemotherapy regimens often resulted in a response rate of <20%. A recent phase III trial documented a 41.3% response rate for cisplatin plus pemetrexed. In the future, new multimodality regimens featuring novel targeted therapies directed against molecular targets, such as the vascular endothelial growth factor, hold the greatest promise for improved outcomes in MPM. The standard radiographic assessment of response to MPM therapy remains a poor surrogate for clinically relevant endpoints such as median survival. Furthermore, it is not currently known whether aggressive multimodality treatment for MPM will improve survival or quality of life above and beyond symptomatic care. Ongoing clinical trials are comparing chemotherapy and surgery with supportive care in an effort to define the role of different therapies in MPM. MPM treatment is a costly public health issue; after efficacy is proven, additional studies are needed to measure the cost effectiveness of MPM treatment regimens.

Evaluation of simian virus-40 as a biological prognostic factor in Egyptian patients with malignant pleural mesothelioma

The association between simian virus (SV40) and malignant pleural mesothelioma (MPM) suggests an etiological role for SV40. However, exact pathogenetic mechanisms and possible prognostic value are not clear. The purpose of the present paper was to investigate 40 Egyptian MPM patients for the presence of SV40 DNA, altered Rb expression and p53 gene status using immunohistochemistry and molecular techniques. The relation between SV40, asbestos exposure, Rb, p53 and their contribution to the overall survival (OS) were also assessed. SV40 DNA was detected in 20/40 patients and asbestos exposure in 31 patients; 18 of them were SV40 positive. Altered p53 and Rb expression were detected in 57.5% and 52.5%, respectively, with no p53 mutation. Univariate analysis showed a significant correlation between OS and stage (P = 0.03), performance status (P = 0.04), p53 overexpression (P = 0.05), asbestos exposure (P = 0.002) and SV40 (P = 0.001). Multivariate analysis showed that when SV40 and asbestos exposure were considered together, only combined positivity of both was an independent prognostic factor affecting the OS (P = 0.001). SV40 and asbestos exposure are common in Egyptian MPM, denoting a possible etiological role and a synergistic effect for both agents. Combined positivity for SV40 and asbestos exposure is an independent prognostic factor in MPM, having a detrimental effect on OS.

Peptide Epitopes from the Wilms' Tumor 1 Oncoprotein Stimulate CD4+and CD8+T Cells That Recognize and Kill Human Malignant Mesothelioma Tumor Cells

PURPOSE

Wilms' tumor 1 protein (WT1), a transcription factor overexpressed in malignant mesothelioma, leukemias, and other solid tumors, is an ideal target for immunotherapy. WT1 class I peptide epitopes that were identified and shown to stimulate CD8(+) T cells are being tested as vaccine candidates in several clinical trials. The induction and maintenance of a robust memory CD8(+) cytotoxic T-cell response requires CD4(+) T-cell help.

EXPERIMENTAL DESIGN

Three HLA class II peptide epitopes of WT1 with high predictive affinities to multiple HLA-DRB1 molecules were identified using the SYFPEITHI algorithm. Due to the highly polymorphic nature of the HLA class II alleles, such reactivity is critical in the development of a broadly useful therapeutic. One of the WT1 CD4(+) peptide epitopes, 122-140, comprises a previously identified CD8(+) peptide epitope (126-134). By mutating residue 126 from an arginine to a tyrosine, we embedded a synthetic immunogenic analogue CD8(+) epitope (126-134) inside the longer peptide (122-140). This analogue was previously designed to improve immunogenicity and induce a potent CD8(+) response.

RESULTS

WT1 peptides 328-349 and 423-441 are able to stimulate a peptide-specific CD4(+) response that can recognize WT1(+) tumor cells in multiple HLA-DRB1 settings as determined by IFN-gamma enzyme-linked immunospot assays. The mutated WT1 peptide epitope 122-140 is able to induce CD4(+) and cytotoxic CD8(+) WT1-specific T-cell responses that can recognize the native WT1 epitopes on the surface of human WT1(+) cancer cells. Cross-priming experiments showed that antigen-presenting cells pulsed with either mesothelioma or leukemia tumor lysates can process and present each of the CD4(+) peptides identified.

CONCLUSIONS

These studies provide the rationale for using the WT1 CD4(+) peptides in conjunction with CD8(+) peptide epitopes to vaccinate patients with WT1-expressing cancers.

Biphasic malignant mesothelioma cases with osseous differentiation and long survival: a review of the literature

This report describes two cases of diffuse biphasic malignant mesothelioma with osseous differentiation and long survival. Two male patients aged 66 and 54 years presented with chest pain, bloody pleural effusions, and diffuse and nodular pleural thickening. They both had a history of prolonged asbestos exposure. Sarcomatoid and epithelioid areas were identified on histopathological examination. In addition, there were foci of ossification. Epithelioid tumor cells as well as benign osteoclasts within the ossification reacted positively for cytokeratin 5/6, whereas sarcomatoid areas were negative. Both patients survived 39 and 69 months, respectively. To our knowledge, these two cases with biphasic malignant mesothelioma and osseous differentiation with long survival are the first to be described from Central Anatolia.

Malignant pleural mesothelioma: a comprehensive review

BACKGROUND

The incidence of malignant mesothelioma continues to increase, but the disease remains difficult to detect early and treat effectively.

METHODS

The authors review the pathogenesis, incidence, clinical presentation, diagnosis, pathology, and both standard and experimental treatments for mesothelioma.

RESULTS

When possible, surgery (video-assisted thoracoscopy, pleurectomy/decortication, or extrapleural pneumonectomy) is utilized. Effects on underlying structures limit application of radiation therapy, but some systemic agents are beginning to enhance survival.

CONCLUSIONS

The disease is expected to increase in incidence till 2020, so awareness of this entity as a possible diagnosis should be heightened. In patients with advanced disease, several newer antitumor agents are already showing a capability of extending survival so it is not unreasonable to expect further progress in this area.

Expression of Cancer-Associated Molecules in Malignant Mesothelioma

Malignant mesothelioma (MM) is a malignant tumor derived from mesothelial cells, native cells of the body cavities. Exposure to asbestos is the most strongly established etiologic factor, predominantly for the most common disease form, pleural mesothelioma. The pathogenesis of MM involves the accumulation of extensive cytogenetic changes, as well as cancer-related phenotypic alterations that facilitate tumor cell survival, invasion and metastasis. This review presents current knowledge regarding the biological characteristics of this disease that are linked to the so-called hallmarks of cancer. In addition, data suggesting that the anatomic site (solid tumor vs. effusion) affects the expression of metastasis-associated and regulatory molecules in MM are presented. Finally, recent work in which high-throughput methodology has been applied to MM research is reviewed. The data obtained in the reviewed research may aid in defining new prognostic markers and therapeutic targets for this aggressive disease in the future.

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

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

Extrapleural pneumonectomy in children

BACKGROUND/PURPOSE

Extrapleural pneumonectomy (EPP) is an en bloc resection of the pleura, lung, diaphragm, and pericardium. EPP in the pediatric population has not been reported in the literature. We report our experience of using EPP in children to treat a variety of malignancies that involve the pleural surface.

METHODS

We performed a retrospective review of all children treated through EPP at our institution. Data were obtained from patient charts and a pediatric database. All patients underwent en bloc resection of the pleura, lung, diaphragm, and pericardium and reconstruction.

RESULTS

Four patients underwent EPP from 2000 to 2004 for inflammatory myofibroblastic tumor, spindle cell sarcoma, metastatic neuroblastoma, and malignant mesothelioma. The patients' ages were from 6 to 11 years. The patient with metastatic neuroblastoma had recurrent disease in the left chest 1 year after EPP and died of sepsis; the patient with mesothelioma died of disease extension into the abdomen 1.5 years later. The other 2 patients are free of disease.

CONCLUSIONS

EPP can be performed with curative intent in selected pediatric patients with pleural-based malignancies. EPP should be included in the armamentarium of the pediatric thoracic surgeon and evaluated in larger studies.

Pathology of the Pleura

The pleura and lung are intimately associated and share many pathologic conditions. Nevertheless, they represent two separate organs of different embryonic derivation and with different yet often symbiotic functions. In this article, the authors explore the pathologic manifestations of the many conditions that primarily or secondarily affect the pleura.

Management of Malignant Pleural Mesothelioma

Malignant mesothelioma is increasing in incidence globally and has no known cure. Its unique clinical feature of local infiltration along tissue planes makes it a difficult neoplasm to manage. There have been few randomized controlled trials regarding treatment options, although these have increased in recent years, and results are eagerly awaited. This article summarizes important advances in the management of mesothelioma, especially diagnostic and therapeutic aspects.

["Therapeutic" pleural surgery]

Renewed interest in carcinological pleura surgery for the treatment of mesothelioma has resulted from an increased incidence of the tumor and also better control of postoperative mortality for an operation with a dramatic reputation. Techniques include pleurectomy, pleurodecrotication and wide pleuropneumectomy. To achive isolated resection of the parietal pleura or a combined resection of the parietal and visceral pleura with more or less wide resection of the diaphragm and pericardium. Indications depend on the tumor extension and the patient's status. Mortality, particularly for wide pleuropneumectomy is no well controlled by well-trained teams and is to the order of 5%. The rate of local recurrence is to the order of 10% and can warrant use of local treatments such as intrathoracic hyperthermic chemotherapy. Median survival for operated mesothelioma is 19 months with a 46% five-year survival for the tumors with the best prognosis. At the present time, radical surgical resection is the basis of local treatment for pleural mesothelioma.

Expression of HLA-G in malignant mesothelioma and clinically aggressive breast carcinoma

The aim of the present study was to evaluate HLA-G expression in breast carcinoma and malignant mesothelioma (MM). Malignant breast carcinoma effusions (46) and corresponding solid tumors (39) and 104 MM (26 effusions, 78 solid tumors) were analyzed using immunohistochemistry (IHC). HLA-G protein and mRNA expression were further studied using immunoblotting (IB) and RT-PCR. HLA-ABC expression was analyzed using flow cytometry (FCM). IHC showed predominantly focal HLA-G expression in 12 of 46 (26%) breast carcinoma effusions and 16 of 39 (41%) solid lesions. In MM, 20 of 78 (26%) solid lesions and 14 of 26 (54%) effusions were focally HLA-G positive. Expression in MM was higher in effusions (p=0.008). IB showed more frequent HLA-G expression in MM compared with breast carcinoma effusions, while RT-PCR showed HLA-G mRNA expression in both tumors. FCM showed conserved HLA-ABC expression in 15 of 15 effusions. Breast cancer patients with HLA-G-positive tumor cells had shorter disease-free survival (mean 37 vs 85, median 25 vs 31 months), though not significantly (p=0.14). In conclusion, HLA-G is focally expressed in MM and breast carcinoma, while HLA-ABC expression is conserved. However, the up-regulated expression of HLA-G in MM effusions and its possible association with shorter disease-free survival in advanced stage of breast carcinoma suggest a possible role in immune response evasion in some tumors.

Multimodality treatments in the management of malignant pleural mesothelioma: an update

Malignant pleural mesothelioma (MPM) is relatively unique among cancers because the local and regional disease rather than the systemic disease usually contributes to death. Because of its multifocal distribution in the chest, MPM progresses locally by compressing the lung, heart, and major vessels and causes death by cardiac tamponade and lung collapse physiology. The therapy for this aggressive local malignancy is currently inadequate. In most cases there is no sufficient time for systemic disease to develop or contribute to mortality. The first order of therapy in MPM is currently, as it has been for decades, to control effectively the tumor's locoregional spread and then deal with controlling the distant disease.