AbstractBackgroundPleural mesothelioma (PM) is typically diagnosed late during the disease. Earlier detection can increase the chance of effective therapy. Recurrent pleural effusions are the earliest symptoms displaying an array of cytomorphological changes from reactive atypia to malignancy. Diagnosis is possible on effusion cytology by applying molecular and immunocytochemical markers, the main difficulty being when to suspect PM and to differentiate PM from metastatic adenocarcinoma and reactive mesothelial proliferations.MethodsWe evaluated the diagnostic performance of two immunocytochemical dual stains (BerEp4/Calretinin and Desmin/Epithelial Membrane Antigen (EMA)) on 149 ethanol‐fixed cytospin preparation as an initial step to solve the mentioned diagnostic difficulty. The immunocytochemical reactivity pattern was evaluated by two independent investigators. The final diagnosis corresponded to PM (n = 20), metastatic adenocarcinoma (n = 83), and mesotheliosis (n = 46) in these cases.ResultsCalretinin had 99% specificity and 98% sensitivity for indicating a mesothelial phenotype, while BerEp4 distinguished the adenocarcinoma cases with 98% specificity and 99% sensitivity. EMA displayed 96% specificity and 99% sensitivity in malignant cases, while Desmin without EMA present showed 99% specificity and 96% sensitivity for indicating benign mesothelial proliferation.ConclusionsInterpretation of the four immunoreactions is improved when performed as dual stains. The dual staining is a useful tool in the initial handling of atypical effusions and guides the subsequent choice of antibody panels for more detailed subclassification of malignant effusions.

The effect of cervical screening on cervical adenocarcinoma has been variable, possibly because the risk associated with the precursor atypical glandular cells (AGC) is not well known. A cohort of all 885 women in the capital region of Sweden with AGC, a concomitant human papillomavirus (HPV) analysis, and a histopathology was followed until 2019. Cumulative incidence proportions of cervical intraepithelial lesion grade 3 or worse (CIN3+) by HPV type was determined by 1-Kaplan-Meier estimates. Hazard ratios (HR) for CIN3+ or for invasive cancer were estimated with Cox regression. After 2 years of follow-up, the cumulative incidence proportions of CIN3+ were 80% (95% confidence interval [CI]: 74-86%), 58% (95% CI: 50-60%) and 10% (95% CI: 5-18%) among HPV16/18 positive, "other HPV" positive and HPV-negative women, respectively. Among the 300 women with HPV16/18 positive AGC, 217 developed CIN3+ of which 35 were invasive cervical cancer. The 2-year cumulative invasive cancer risk for HPV16/18 positive AGC was 17% (95% CI: 12-24%). Primary HPV-screening had a similar yield of CIN3+ as cytology screening, albeit HPV-negative AGC is by design not detected by HPV screening. Among 241 women with HPV-negative AGC, 11 developed CIN3+ mostly after clinically indicated samples. We found no significant risk differences depending on age or sampling indication. The low CIN3+ risk after HPV-negative AGC implies safety of primary HPV screening. The high risk of invasive cervical cancer after HPV16/18 positive AGC implies that management of this finding is a priority in cervical screening.

Syndecan-1, a cell surface heparan sulfate proteoglycan, participates in a multitude of cellular processes, and it acts as a “fine tuner of cellular signaling.” Syndecan-1 is present in most epithelial tissues and on the cellular level, it is critical for tumor cell differentiation, adhesion, growth, and invasion. Its expression carries valuable information related to the clinical outcome and prognosis of most solid tumors. Despite considerable efforts to decipher its significance in tumor development and progression, current data point toward both inhibitory and promoting effects, sometimes in a contradictory manner. A large body of evidence shows the importance of the aberrant cytoplasmic-, nuclear-, stromal localization of soluble/shed syndecan-1. In this chapter, we highlight the structure and various interactions of syndecan-1 in relation to its cellular localization and its impact on the prognosis of individual tumor types.

The globally recommended public health policy for cervical screening is primary human papillomavirus (HPV) screening with cytology triaging of positives. To ensure optimal quality of laboratory services we have conducted regular audits of cervical smears taken before cervical cancer or cancer in situ (CIN3+) within an HPV-based screening program. The central cervical screening laboratory of Stockholm, Sweden, identified cases of CIN3+ who had had a previous cervical screening test up to 3 years before and randomly selected 300 cervical liquid-based cytology (LBC) samples for auditing. HPV testing with Roche Cobas was performed either at screening or with biobanked samples. HPV negative samples and subsequent biopsies were retrieved and tested with modified general primer HPV PCR and, if still HPV-negative, the LBCs and biopsies were whole genome sequenced. The Cobas 4800 detected HPV in 1020/1052 (97.0%) LBC samples taken before CIN3+. Further analyses found HPV in 28 samples, with nine of those containing HPV types not targeted by the Cobas 4800 test. There were 4 specimens (4/1052, 0.4%) where no HPV was detected. By comparison, the proportion of CIN3+ cases that were positive in a previous cytology were 91.6%. We find that the routine HPV screening test had a sensitivity in the real-life screening program of 97.0%. Regular laboratory audits of cervical samples taken before CIN3+ can be readily performed within a real-life screening program and provide assurance that the laboratory of the real-life program has the expected performance.

Malignant mesothelioma (MM) is an aggressive tumor of the serosal cavities. Angiogenesis is important for mesothelioma progression, but so far, anti-angiogenic agents have not improved patient survival. Our hypothesis is that better understanding of the regulation of angiogenesis in this tumor would largely improve the success of such a therapy. Syndecan-1 (SDC-1) is a transmembrane heparan sulfate proteoglycan that acts as a co-receptor in various cellular processes including angiogenesis. In MM, the expression of SDC-1 is generally low but when present, SDC-1 associates to epithelioid differentiation, inhibition of tumor cell migration and favorable prognosis, meanwhile SDC-1 decrease deteriorates the prognosis. In the present study, we studied the effect of SDC-1 overexpression and silencing on MM cells ability to secrete angiogenic factors and monitored the downstream effect of SDC-1 modulation on endothelial cells proliferation, wound healing, and tube formation. This was done by adding conditioned medium from SDC-1 transfected and SDC-1 silenced mesothelioma cells to endothelial cells. Moreover, we investigated the interplay and molecular functional changes in angiogenesis in a co-culture system and characterized the soluble angiogenesis-related factors secreted to the conditioned media. We demonstrated that SDC-1 over-expression inhibited the proliferation, wound healing, and tube formation of endothelial cells. This effect was mediated by a multitude of angiogenic factors comprising angiopoietin-1 (Fold change ± SD: 0.65 ± 0.07), FGF-4 (1.45 ± 0.04), HGF (1.33 ± 0.07), NRG1-β1 (1.35 ± 0.08), TSP-1 (0.8 ± 0.02), TIMP-1 (0.89 ± 0.01) and TGF-β1 (1.35 ± 0.01). SDC-1 silencing increased IL8 (1.33 ± 0.06), promoted wound closure, but did not influence the tube formation of endothelial cells. Pleural effusions from mesothelioma patients showed that Vascular Endothelial Growth Factor (VEGF) levels correlate to soluble SDC-1 levels and have prognostic value. In conclusion, SDC-1 over-expression affects the angiogenic factor secretion of mesothelioma cells and thereby inhibits endothelial cells proliferation, tube formation, and wound healing. VEGF could be used in prognostic evaluation of mesothelioma patients together with SDC-1.

Tumor cells undergoing epithelial-mesenchymal transition (EMT) lose cell surface adhesion molecules and gain invasive and metastatic properties. EMT is a plastic process and tumor cells may shift between different epithelial-mesenchymal states during metastasis. However, how this is regulated is not fully understood. Syndecan-1 (SDC1) is the major cell surface proteoglycan in epithelial cells and has been shown to regulate carcinoma progression and EMT. Recently, it was discovered that SDC1 translocates into the cell nucleus in certain tumor cells. Nuclear SDC1 inhibits cell proliferation, but whether nuclear SDC1 contributes to the regulation of EMT is not clear. Here, we report that loss of nuclear SDC1 is associated with cellular elongation and an E-cadherin-to-N-cadherin switch during TGF-β1-induced EMT in human A549 lung adenocarcinoma cells. Further studies showed that nuclear translocation of SDC1 contributed to the repression of mesenchymal and invasive properties of human B6FS fibrosarcoma cells. The results demonstrate that nuclear translocation contributes to the capacity of SDC1 to regulate epithelial-mesenchymal plasticity in human tumor cells and opens up to mechanistic studies to elucidate the mechanisms involved.

Extracellular vesicles (EVs), comprising exosomes, microvesicles, and apoptotic bodies, are released by all cells into the extracellular matrix and body fluids, where they play important roles in intercellular communication and matrix remodeling in various pathological conditions. Malignant pleural mesothelioma (MPM) is a primary tumor of mesothelial origin, predominantly related to asbestos exposure. The detection of MPM at an early stage and distinguishing it from benign conditions and metastatic adenocarcinomas (AD) is sometimes challenging. Pleural effusion is often the first available biological material and an ideal source for characterizing diagnostic and prognostic factors. Specific proteins have previously been identified as diagnostic markers in effusion, but it is not currently known whether these are associated with vesicles or released in soluble form. Here, we study and characterize tumor heterogeneity and extracellular vesicle diversity in pleural effusion as diagnostic or prognostic markers for MPM. We analyzed extracellular vesicles and soluble proteins from 27 pleural effusions, which were collected and processed at the department of pathology and cytology at Karolinska University Hospital, representing three different patient groups, MPM (n = 9), benign (n = 6), and AD (n = 12). The vesicles were fractionated into apoptotic bodies, microvesicles, and exosomes by differential centrifugation and characterized by nanoparticle tracking analysis and Western blotting. Multiplex bead-based flow cytometry analysis showed that exosomal markers were expressed differently on EVs present in different fractions. Further characterization of exosomes by a multiplex immunoassay (Luminex) showed that all soluble proteins studied were also present in exosomes, though the ratio of protein concentration present in supernatant versus exosomes varied. The proportion of Angiopoietin-1 present in exosomes was generally higher in benign compared to malignant samples. The corresponding ratios of Mesothelin, Galectin-1, Osteopontin, and VEGF were higher in MPM effusions compared to those in the benign group. These findings demonstrate that relevant diagnostic markers can be recovered from exosomes.

Diffuse malignant mesothelioma (MM) is an incurable tumour of the serosal membranes, which is often caused by exposure to asbestos and commonly diagnosed at advanced stage. Malignant mesothelioma in situ (MMIS) is now included as diagnostic category by the World Health Organization (WHO). However, our international survey of 34 pulmonary pathologists with an interest in MM diagnosis highlights inconsistency regarding how the diagnosis is being made by experts, despite published guidelines. Whilst the WHO restricts the diagnosis to surgical samples, the very concept has implication for cytological diagnosis, which is already regarded as controversial in itself by some. MMIS is currently only applicable as precursor to MM with an epithelioid component, and raises the possibility for different molecular pathways for different histological MM subtypes. The clinical implications of MMIS at this stage are uncertain, but aggressive therapies are being initiated in some instances. Based on the results of the survey we here present a critical appraisal of the concept, its clinical and conceptual implications and provide practice suggestions for diagnosis. A low threshold for ancillary testing is suggested. The designations of 'malignant mesothelioma, cannot exclude MMIS' or 'atypical mesothelial proliferation with molecular indicators of malignancy, so-called MMIS' could be used on cytology samples, adding 'no evidence of invasion in sample provided' for surgical samples. Clinical and radiological correlation are integral to diagnosis and best done at multidisciplinary meetings. Finally, collaborative studies are required to improve our understanding of MMIS.

Malignant mesothelioma (MM) is a rare but highly aggressive cancer that primarily originates from the pleura, peritoneum or pericardium. There is a well-established link between asbestos exposure and progression of MM. Direct invasion of the surrounding tissues is the main feature of MM, which is dependent on dysregulated communication between the mesothelium and the microenvironment. This communication is dependent on the dynamic organization of the cytoskeleton. We have analyzed the organization and function of key cytoskeletal components in MM cell lines of increasing malignancies measured as migratory and invasive properties, and we show that highly malignant and invasive MM cells have an organization of the actin filament and vimentin systems that is distinct from the less malignant MM cell lines. In addition, the Hippo tumor suppressor pathway was inactivated in the invasive MM cells, which was seen as increased YAP nuclear localization.

Malignant pleural mesothelioma (MPM) is a highly aggressive and therapy resistant pleural malignancy that is caused by asbestos exposure. MPM is associated with poor prognosis and a short patient survival. The survival time is strongly influenced by the subtype of the tumor. Dyspnea and accumulation of pleural effusion in the pleural cavity are common symptoms of MPM. The diagnostic distinction from other malignancies and reactive conditions is done using histopathology or cytopathology, always supported by immunohistochemistry, and sometimes also by analyses of soluble biomarkers in effusion supernatant. We evaluated the soluble angiogenesis related molecules as possible prognostic and diagnostic biomarkers for MPM by Luminex multiplex assay. Pleural effusion from 42 patients with malignant pleural mesothelioma (MPM), 36 patients with adenocarcinoma (AD) and 40 benign (BE) effusions were analyzed for 10 different analytes that, in previous studies, were associated with angiogenesis, consisting of Angiopoietin-1, HGF, MMP-7, Osteopontin, TIMP-1, Galectin, Mesothelin, NRG1-b1, Syndecan-1 (SDC-1) and VEGF by a Human Premixed Multi-Analyte Luminex kit. We found that shed SDC-1 and MMP-7 levels were significantly lower, whereas Mesothelin and Galectin-1 levels were significantly higher in malignant mesothelioma effusions, compared to adenocarcinoma. Galectin-1, HGF, Mesothelin, MMP-7, Osteopontin, shed SDC-1, NRG1-β1, VEGF and TIMP-1 were significantly higher in malignant pleural mesothelioma effusions compared to benign samples. Moreover, there is a negative correlation between Mesothelin and shed SDC-1 and positive correlation between VEGF, Angiopoietin-1 and shed SDC-1 level in the pleural effusion from malignant cases. Shed SDC-1 and VEGF have a prognostic value in malignant mesothelioma patients. Collectively, our data suggest that MMP-7, shed SDC-1, Mesothelin and Galectin-1 can be diagnostic and VEGF and SDC-1 prognostic markers in MPM patients. Additionally, Galectin-1, HGF, Mesothelin, MMP-7, Osteopontin, shed SDC-1 and TIMP-1 can be diagnostic for malignant cases.

The global incidence of malignant mesothelioma (MM) causes considerable disease burden, suffering and health care costs. Beside preventive measures and ban the use of asbestos, early diagnosis would largely improve the chance of curative treatment. Current histologic criteria, however, requiring presence of invasion in the surrounding fatty tissue fail to identify MM in sufficiently early stage. Unilateral accumulation of pleural effusion is one of the earliest clinical manifestations of MM that occurs in approximately 90% of the patients. Therapeutic thoracocenthesis is necessary to remove the fluid and to relieve patients' symptoms. This effusion is easily accessible and offers early and minimally invasive diagnosis by combining cytology with immunologic, molecular- and biomarker analyses. Typically, the fluid is rich in malignant cells and cell groups, but incipient stages of the disease may be difficult to recognize as the malignant cells can be masked by presence of inflammatory or reactive mesothelial cells. Recurrent, hemorrhagic and cell rich effusion should always be suspicious for MM and adequately prepared and analyzed to provide necessary information for subsequent therapy. Importantly, early detection of MM by integrating cytology and molecular approaches has high sensitivity and positive predictive value and has a major impact on patient survival. Thus, a conclusive positive MM cytology should lead to treatment without delay. This review summarizes molecular and diagnostic criteria of MM diagnosis.

Syndecan-1 (SDC1) is a cell surface heparan sulfate proteoglycan (HSPG), which regulates various signaling pathways controlling the proliferation and migration of malignant mesothelioma and other types of cancer. We have previously shown that SDC1 can translocate to the nucleus in mesothelioma cells through a tubulin-dependent transport mechanism. However, the role of nuclear SDC1 is largely unknown. Here, we performed co-immunoprecipitation (Co-IP) of SDC1 in a mesothelioma cell line to identify SDC1 interacting proteins. The precipitates contained a large number of proteins, indicating the recovery of protein networks. Proteomic analysis with a focus on nuclear proteins revealed an association with pathways related to cell proliferation and RNA synthesis, splicing and transport. In support of this, the top RNA splicing candidates were verified to interact with SDC1 by Co-IP and subsequent Western blot analysis. Further loss- and gain-of-function experiments showed that SDC1 influences RNA levels in mesothelioma cells. The results identify a proteomic map of SDC1 nuclear interactors in a mesothelioma cell line and suggest a previously unknown role for SDC1 in RNA biogenesis. The results should serve as a fundament for further studies to discover the role of nuclear SDC1 in normal and cancer cells of different origin.

Malignant mesotheliomas (MMs) are highly aggressive mesenchymal tumors that originate from mesothelial cells lining serosal cavities; i.e., the pleura, peritoneum, and pericardium. Classically, there is a well-established link between asbestos exposure, oxidative stress, release of reactive oxygen species, and chronic inflammatory mediators that leads to progression of MMs. MMs have an intermediate phenotype, with co-expression of mesenchymal and epithelial markers and dysregulated communication between the mesothelium and the microenvironment. We have previously shown that the organization and function of key cytoskeletal components can distinguish highly invasive cell lines from those more indolent. Here, we used these tools to study three different types of small-molecule inhibitors, where their common feature is their influence on production of reactive oxygen species. One of these, imipramine blue, was particularly effective in counteracting some key malignant properties of highly invasive MM cells. This opens a new possibility for targeted inhibition of MMs based on well-established molecular mechanisms.

A conclusive diagnosis of malignant mesothelioma (MM) can be based on effusion cytology using the guidelines for the cytopathologic diagnosis of epithelioid and mixed-type MM. Briefly, the diagnosis is obtained when the mesothelial phenotype of malignant cells is established by ancillary techniques. This study is based on the comparison of the overall survival rates of patients with MM when diagnosed by effusion cytology, histopathology, or a combination of both. A total of 144 patients were diagnosed with epithelioid and mixed-type pleural MM at Karolinska University Hospital between 2004 and 2013. The diagnosis was obtained by histopathology in 74 cases and by cytological examination of pleural effusion in 70 cases. In 29 of the latter cases, a diagnostic biopsy was obtained simultaneously. A total of 104 patients received chemotherapy. All diagnoses were supported by clinical findings, including computer tomography scans. The median time between first symptoms and diagnosis was similar for cytology and histopathology. However, a delay of more than 6 months after first symptoms was seen in many patients in the histopathology group, resulting in late onset of treatment. The overall survival and proportion of long-term survival were significantly better for cases diagnosed by cytology. Similarly, a better survival, following a cytological diagnosis, was also seen in patients who were only provided the best supportive care. Accurate cytological diagnosis enables conclusive diagnosis of MM. Our finding enables the initiation of treatment as soon as the cytological diagnosis is established, avoiding further delay and deterioration of patient survival and possibilities for treatment.

Serous effusion fluid is one of the most commonly encountered specimens in routine cytopathology practice. It provides invaluable information about the patient and the clinical status; but to get the most of it, specimen handling and processing must be carried out properly. Cytomorphology is the basis of a successful analysis which should complemented by ancillary tests when needed. A wide spectrum of ancillary techniques - ranging from immunocytochemistry and flow cytometry to different assays of molecular pathology - can be applied to serous effusions. This article describes the acquisition and management of serous effusion fluids, methods for preservation and transportation, different techniques of cytopreparation, application of immunocytochemistry, flow cytometry, and fluorescence in-situ hybridization (FISH), as well as DNA extraction for polymerase chain reaction (PCR) and next generation sequencing (NGS). Principles of bio-banking of effusion samples are also discussed which is getting more important in correlation with the developments in personalized medicine.

BACKGROUND AND AIMS:Detection of early cholangiocarcinoma (CCA) in primary sclerosing cholangitis (PSC) is challenging. The aim of this study was to evaluate the diagnostic accuracy of a stepwise approach to biliary brush cytology with sequential use of fluorescence in-situ hybridization (FISH) for the detection of biliary malignancy in PSC. METHOD:We retrospectively studied consecutive patients with PSC who underwent biliary brushings at Karolinska University Hospital between 2009 and 2015 (n = 208). Brush samples were categorized as benign, equivocal (atypical or suspicious) and malignant. Equivocal cases were further analysed with FISH. Samples with a malignant cytology or positive FISH were considered positive. The diagnosis was determined after 12 months of follow-up. RESULTS:The diagnosis CCA was confirmed in 15 patients (7%), high-grade dysplasia in three patients, and low-grade dysplasia in five patients at follow-up. Using the diagnostic algorithm, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) for a diagnosis of CCA were 80% (95%CI 52%-96%), 96% (95%CI 92%-98%), 60% (95%CI 36%-81%) and 98% (95% CI 95%-100%). In patients with equivocal cytology (n = 61), the sensitivity for CCA diagnosis increased to 100% (95%CI 72%-100%) with a lower PPV of 58% (95%CI 34%-78%). The diagnostic accuracy for detection of CCA in all patients was 95% (95%CI 91%-97%). CONCLUSION:Biliary brush cytology with sequential use of FISH in equivocal cases seems to be a highly predictive diagnostic test for CCA in PSC. These results support the use of FISH when cytology is equivocal for detection of biliary malignancy in PSC.