Kao SC, Yan TD, Lee K, Burn J, Henderson DW, Klebe S, Kennedy C, Vardy J, Clarke S, van Zandwijk N, McCaughan BC.

Asbestos Diseases Research Institute, Bernie Banton Centre, Sydney, Australia.

Abstract

Introduction: Histological subtype is an established prognostic factor in malignant pleural mesothelioma (MPM). We retrospectively investigated the accuracy of classifying histological subtype on diagnostic biopsies and examined the impact of different diagnostic procedures on the outcome.

Methods: Consecutive patients with histologically confirmed MPM who underwent extrapleural pneumonectomy (EPP) from 1994 to 2009 were included. Patient records were reviewed, and the initial diagnoses of histological subtype were obtained. The archival EPP specimens were reviewed by a panel of pathologists. The histological subtype obtained at review was compared with the initial diagnosis.

Results: Eighty-five patients underwent EPP. Two patients achieved a pathological complete response after neoadjuvant chemotherapy, leaving 83 patients to be included in this review. Different diagnostic methods were used before EPP: 81% thoracoscopy; 7% thoracotomy; 11% computed tomography-guided procedure; and 1% other. Patients determined to have an epithelial subtype (n = 64) at EPP were diagnosed correctly at initial diagnostic biopsy in 84% of cases, whereas patients considered to have a biphasic subtype (n = 19) at EPP were diagnosed correctly at diagnostic biopsy in 26% of cases. The sensitivity and specificity of diagnostic biopsy for epithelial MPM was 93% and 31%, respectively. The overall subtype misclassification rate was 20%. Biopsy by thoracotomy was most accurate in subtype classification (83%) compared with thoracoscopy (74%) and computed tomography-guided procedure (44%).

Conclusions: The determination of histological subtype from a diagnostic biopsy is difficult due to sampling error, but an adequate specimen obtained from surgical biopsy increases the accuracy of subtype classification compared with radiological-guided biopsies.

Foss KM, Sima C, Ugolini D, Neri M, Allen KE, Weiss GJ.

*Translational Genomics Research Institute, Phoenix, Arizona; †Department of Oncology, Biology and Genetics, University of Genoa, Genoa; ‡Unit of Epidemiology, Biostatistics and Clinical Trials, National Cancer Research Institute, Genoa; §Rehabilitative Pneumology, IRCCS San Raffaele Pisana, Rome, Italy; and ∥Virginia G. Piper Cancer Center at Scottsdale Healthcare, Scottsdale, Arizona.

Abstract

Introduction: The ability to diagnose non-small cell lung cancer (NSCLC) at an early stage may lead to improved survival. The aim of this study was to identify differentially expressed serum-based microRNAs (miRNAs) between patients with early-stage NSCLC and controls. These miRNAs may serve as biomarkers for NSCLC early detection.

Methods: miRNA profiling was performed on total RNA extracted from serum obtained from 22 individuals (11 controls and 11 patients with early-stage NSCLC). Quantitative polymerase chain reaction (qPCR) was used to validate the profiling results in the discovery set and in a validation set of 31 controls and 22 patients with early-stage NSCLC. Additionally, six matched plasma samples (four NSCLC cases and two controls) and three serum mesothelioma samples were analyzed by qPCR. Receiver operating characteristic curves were generated for each possible combination of the miRNAs measured by qPCR.

Results: The expression of hsa-miR-1254 and hsa-miR-574-5p was significantly increased in the early-stage NSCLC samples with respect to the controls. Receiver operating characteristic curves plotting these two miRNAs were able to discriminate early-stage NSCLC samples from controls with 82% and 77% of sensitivity and specificity, respectively, in the discovery cohort and with 73% and 71% of sensitivity and specificity, respectively, in the validation cohort. The mesothelioma and plasma samples did not seem to classify into either NSCLC or control groups.

Conclusions: Serum miRNAs are differentially expressed between patients with early-stage NSCLC and controls. The utility of miR-1254 and miR-574-5p serum-based biomarkers as minimally invasive screening and triage tools for subsequent diagnostic evaluation warrants additional validation.

Marini V, Michelazzi L, Cioé A, Fucile C, Spigno F, Robbiano L.

Department of Internal Medicine, Division of Clinical Pharmacology and Toxicology, University of Genoa, Viale Benedetto XV, 2, I-16132 Genoa, Italy.

Abstract

Inhalation of asbestos, a mineral extensively used in a variety of applications, is strongly associated with malignant mesothelioma (MM), a fatal cancer of the pleura. Soluble mesothelin-related peptides (SMRP) are a promising biomarker suggested for the screening of MM in healthy asbestos-exposed subjects. In the present study a comparison of micronucleus (Mn) frequencies in peripheral blood lymphocytes (PBL) between 44 asbestos-exposed and 22 control individuals has been performed, and the correlation with serum SMRP has been examined. SMRP levels were found to be significantly higher in subjects exposed to asbestos and in their various subgroups than in controls. Concerning micro-nucleated lymphocytes, a statistically significant difference from controls was seen in the percentages of both micro-nucleated mononucleated lymphocytes (MnMNL) and micro-nucleated binucleated lymphocytes (MnBNL), but the difference was markedly higher for the percentage of micro-nucleated polynucleated lymphocytes (MnPNL). With respect to the correlation between the frequency of the three types of micronucleated lymphocytes and serum-SMRP values of asbestos-exposed subjects, it was statistically significant for MnMNL, but not for MnBNL and MnPNL.

Galbis JM, Mata M, Guijarro R, Esturi R, Figueroa S, Arnau A.

Thoracic Surgery Service, General University Hospital of Valencia, Valencia, Spain.

Abstract

Introduction: The aim of this study was to investigate the effectiveness of thoracoscopy in the diagnosis of non-affiliated pleural effusions (PE).

Material and methods: A five-year prospective study including data from 110 patients that were clinically diagnosed as benign (14.5%), malign (34.5%) and non-affiliated (50.9%). PE in patents without oncology disease and negative biopsy or cytology were considered as benign. Malignant diagnosis was established according to a pleural biopsy, compatible cytology and/or clinical features. Remaining cases were considered as non-affiliated. Thoracoscopy was done under local anaesthesia and sedation.

Results: Thoracoscopy confirmed previous clinical diagnosis of benignity and malignity. Regarding non-affiliated patients, 30.35% were diagnosed after thoracoscopy as unspecific pleuritis, 17.86% mesothelioma and 1.79% pleural tuberculosis (TBC). The other 48.21% of patients reported as non-affiliated were diagnosed with pleural carcinoma. Statistical analysis did not reveal differences between frequencies analysed.

Conclusions: Our results indicate that thoracoscopy is a cost-effective and reliable technique for obtaining histological diagnosis in PE and also allows a directed pleurodesis if indicated.

Kao SC, Lee K, Armstrong NJ, Clarke S, Vardy J, van Zandwijk N, Reid G, Burn J, McCaughan BC, Henderson DW, Klebe S.

*Asbestos Diseases Research Institute, Bernie Banton Centre, Concord, Australia †Department of Medical Oncology, Sydney Cancer Centre, Concord, Australia ‡The University of Sydney, Sydney, Australia §Department of Anatomical Pathology, Concord Repatriation General Hospital, Concord, Australia ||Cancer Program, Garvan Institute of Medical Research, Darlinghurst, Australia ¶Davies Campbell de Lambert Pathology, Sydney, Australia **Department of Cardiothoracic Surgery, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia ††Department of Anatomical Pathology, Flinders Medical Centre and SA Pathology, Adelaide, South Australia, Australia.

Abstract

Aims: Tissue microarray (TMA) technology has been utilised for assessment of cancers including malignant pleural mesothelioma (MPM). Given the intralesional heterogeneity of MPM, it is questionable if TMAs can adequately represent MPMs. We here investigate the validity of TMAs for MPM.

Methods: TMAs were constructed from at least five cores for each of 80 archival tumours processed by two centres between 1994 and 2009. The percentage of cases correctly subtyped on TMAs compared with whole sections, in relation to the number of cores analysed, was calculated. Immunohistochemical labelling for calretinin and D2-40 was performed on TMAs and whole sections. To evaluate the validity of quantitative immunohistochemistry, percentages of positive cells were recorded and two-way analysis of variance (ANOVA) performed.

Results: Five cores were assessable for 91% of patients. Four cores were sufficient to reach concordance with the whole-section result in 98% of cases for calretinin and 99% for D2-40. The correlation of the quantitative scores between the whole section and TMA cores was statistically significant (D2-40, rho = 0.84, p < 2.2e-16; calretinin, rho = 0.65, p = 7.9e-11). Neither the origin nor age of the blocks affected the results.

Conclusion: If a minimum of four cores is used, TMA is an appropriate method for immunohistochemistry in MPM.

Murali R, Park K, Leslie KO.

Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, New York.

Abstract

A wide variety of local, regional, and systemic diseases may have pleural manifestations. The scope of this pathology encompasses a wide spectrum ranging from minimal inflammatory changes to highly malignant neoplasms. An overview of the normal structure of the pleura is provided, along with the diseases that may be encountered. Pleural specimens from patients with pneumothorax are rarely encountered by pathologists. In contrast, pathologists frequently receive pleural specimens showing evidence of inflammation, repair, or neoplasm. In these circumstances, an awareness of less common (and often clinically highly important) conditions such as epithelioid hemangioendothelioma and primary pleural malignant mesothelioma is essential. Knowledge of the clinical setting (e.g., disease tempo) and radiological picture (e.g., laterality) is often of great value to the pathologist in arriving at a correct diagnosis. Similarly, knowledge of the normal anatomical considerations and familiarity with the expected pleural histopathology for the most clinically relevant pleural diseases are critical assets for pulmonary physicians in providing optimal care for their patients.

Keywords: Pleura – pathology – disease – infection – neoplasms – mesothelioma

Goyal M, Kodandapani S, Sharanabasappa SN, Palanki SD.

Department of Laboratory Medicine, Indo-American Cancer Institute and Research Centre, Hyderabad, India.

Abstract

Mesothelial cell inclusions in lymph nodes are of rare occurrence and can be mistaken as metastatic adenocarcinomas, mesothelioma or sinus histiocytosis. These are usually found in mediastinal and abdominal lymph nodes and are associated with effusions. We report a case of benign mesothelial cell inclusions in cervical lymph nodes, which was associated with chylous effusion, and immunohistochemistry revealed unusual weak cytoplasmic epithelial membrane antigen positivity in the cells.

Keywords: Adenocarcinoma, chylous effusion, epithelial membrane antigen, mesothelial cell inclusions

Gerbaudo VH, Mamede M, Trotman-Dickenson B, Hatabu H, Sugarbaker DJ.

Division of Nuclear Medicine and Molecular Imaging, Brigham & Women’s Hospital, Harvard Medical School, 75 Francis St., Boston, MA, 02115, USA, vgerbaudo@partners.org.

Abstract

Purpose: This study investigated the diagnostic performance and prognostic value of fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in suspected malignant pleural mesothelioma (MPM) recurrence, in the context of patterns and intensity of FDG uptake, histologic type, and treatment algorithm.

Methods: Fifty patients with MPM underwent FDG PET/CT for restaging 11 ± 6 months after therapy. Tumor relapse was confirmed by histopathology, and by clinical evolution and subsequent imaging. Progression-free survival was defined as the time between treatment and the earliest clinical evidence of recurrence. Survival after FDG PET/CT was defined as the time between the scan and death or last follow-up. Overall survival was defined as the time between initial treatment and death or last follow-up date.

Results: Treatment failure was confirmed in 42 patients (30 epithelial and 12 non-epithelial MPM). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for FDG PET/CT were 97.6, 75, 94, 86, and 95.3%, respectively. FDG PET/CT evidence of single site of recurrence was observed in the ipsilateral hemithorax in 18 patients (44%), contralaterally in 2 (5%), and in the abdomen in 1 patient (2%). Bilateral thoracic relapse was detected in three patients (7%). Simultaneous recurrence in the ipsilateral hemithorax and abdomen was observed in ten (24%) patients and in seven (17%) in all three cavities. Unsuspected distant metastases were detected in 11 patients (26%). Four patterns of uptake were observed in recurrent disease: focal, linear, mixed (focal/linear), and encasing, with a significant difference between the intensity of uptake in malignant lesions compared to benign post-therapeutic changes. Lesion uptake was lower in patients previously treated with more aggressive therapy and higher in intrathoracic lesions of patients with distant metastases. FDG PET/CT helped in the selection of 12 patients (29%) who benefited from additional previously unplanned treatment at the time of failure. Multivariate analysis showed that histologic type remained the only independent predictor of progression-free survival. Survival after relapse was independently predicted by the pattern of FDG uptake and PET nodal status, and overall survival by the maximum standard uptake value.

Conclusion: FDG PET/CT is an accurate modality to diagnose and to estimate the extent of locoregional and distant MPM recurrence, and it carries independent prognostic value. Once the disease recurs, survival outcomes seem to be independent of histologic type and highly dependent on the intensity of lesion uptake and on the pattern of metabolically active disease in FDG PET/CT. Our observations should be considered limited to patients treated surgically with or without perioperative therapies and should not be extrapolated to those unresectable cases treated with chemotherapy alone.

Keywords FDG, FDG PET/CT, Mesothelioma, Lung cancer, Response to treatment, Recurrence, Survival

Sato A, Torii I, Tao LH, Song M, Kondo N, Yoshikawa Y, Hashimoto-Tamaoki T, Hasegawa S, Nakano T, Tsujimura T.

Department of Pathology Department of General Thoracic Surgery Department of Genetics Division of Respiratory Medicine, Department of Internal Medicine, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.

Abstract

Malignant pleural mesothelioma is a refractory tumor with an increasing incidence. In this study, we established six mesothelioma cell lines possessing two allele deletion of the p16(INK4A) gene and one allele deletion of the neurofibromatosis type 2 gene, MM16, MM21, MM26, MM35, MM46, and MM56, from pleural effusion fluids or surgically resected tumors of Japanese patients. MM21, MM26, and MM46 cells failed to develop tumors in BALB/c-nude mice following subcutaneous inoculation. MM16 and MM35 cells slowly generated tumors at the site of subcutaneous inoculation in BALB/c-nude mice, but lost the expression of mesothelioma-related markers, such as calretinin, D2-40, and Wilms’ tumor 1, in the subcutaneous tumors. On the other hand, MM56 cells rapidly generated tumors with the expression of calretinin and D2-40 in BALB/c-nude mice following subcutaneous inoculation. In addition, orthotopic implantation of MM56 cells into BALB/c-nude mice developed diffusely growing thoracic tumors by 3 weeks after implantation. Pleural effusions were observed in these mice 4 weeks after implantation. Thoracic tumors invaded aggressively into the chest wall 5 weeks after implantation and often metastasized into the lung, rib, peritoneum, and pericardial cavity. On the pleural surface, MM56 cells were growing as single or multiple cell layers with reactive mesothelium of recipient mice. These results indicate that MM56 cells can behave in a manner characteristic of human malignant pleural mesothelioma in the thoracic cavity of BALB/c-nude mice. The in vivo model using MM56 cells may be useful to study the biological behavior of malignant pleural mesothelioma and develop its diagnostic and therapeutic strategies.

Hansson M, Zendehrokh N, Ohyashiki J, Ohyashiki K, Westman UB, Roos G, Dejmek A.

Department of Laboratory Medicine, Lund University, Malmö, Sweden.

Abstract

Context: We previously found telomere repeat amplification protocol (TRAP) in situ helpful in the diagnosis of malignancy in effusions, whereas varying sensitivities and specificities for malignancy were reported by investigators using extract-based TRAP.

Objective: To compare the 2 methods and to elucidate the discrepancies between them.

Design: Twenty-three effusions were analyzed. Telomerase activity of whole cell lysate was measured with a Telo TAGGG telomerase polymerase chain reaction ELISA PLUS kit with modifications to exclude polymerase chain reaction inhibitors. TRAP in situ was performed on cytospins. An estimate of total TRAP activity in the specimen was made based on the amount of positive cells, their fluorescence intensity, and the proportion of different cell types in the specimen. The estimate was compared with the level of telomerase activity in cell lysate–based TRAP.

Results: TRAP in situ: Thirteen of 14 malignant cases and 2 of 2 equivocal cases showed moderate/strong reactivity. Five of 7 benign effusions were negative; in 2 of 7, mesothelial cells showed weak reactivity. Cell lysate–based TRAP assay: In 4 cases no internal standard was detected, indicating the presence of polymerase chain reaction inhibitors. The relative telomerase activities were 33.1 to 72.7 with a considerable overlap between malignant (48 ± 9, mean ± SD) and benign (43 ± 9) cases.

Conclusions: The TRAP in situ results correlated to final diagnoses, whereas the cell lysate–based TRAP assay did not differentiate between malignant and benign cases. The varying proportions of positive cells and the variation in fluorescence intensity in the TRAP in situ slides explained some of the discrepancies. The problems encountered with TRAP performed on cell lysates are partly overcome using TRAP in situ.