Prognostic significance of presence and reduplication of basal lamina in malignant pleural mesothelioma

Toll-like receptors: a novel target for therapeutic intervention in intestinal and hepatic ischemia-reperfusion injury?

IMPORTANCE OF THE FIELD

Toll-like receptors (TLRs) are transmembrane proteins that act mainly as sensors of microbes, orchestrating an organism's defense against infections, while they sense also host tissue injury by recognizing products of dying cells. Ischemia-reperfusion injury (IRI) represents one of these tissue damage states in which TLR-mediated mechanisms might be implicated.

AREAS COVERED IN THIS REVIEW

The most recent data on TLR signaling and the latest knowledge regarding the involvement of TLRs in the pathogenesis and progression of intestinal and hepatic IRI are presented. The potential effectiveness of TLR-modulating therapy in intestinal and liver IRI is also analyzed.

WHAT THE READER WILL GAIN

A comprehensive summary of the data suggesting TLR involvement in intestinal and hepatic IRI. Knowledge required for developing TLR modulation strategies against intestinal and hepatic IRI.

TAKE HOME MESSAGE

TLRS play a significant role in both intestinal and hepatic IRI pathophysiology. Better understanding of TLR involvement in such processes may enable the invention of novel TLR-based therapies for IRI in the intestine and liver.

Biomarkers for malignant pleural mesothelioma: current status

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis, whose main etiology is exposure to asbestos fibers. The incidence of MPM is anticipated to increase worldwide during the first half of this century. For various reasons, MPM is difficult to diagnose and is notoriously refractory to most treatments. However, recently two active chemotherapy regimens have been demonstrated to significantly increase survival in patients with MPM, and several therapeutic agents and strategies are currently under evaluation.Researchers have actively sought MPM biomarkers for more than 20 years. Biomarkers would be helpful in managing three clinical aspects of MPM: early diagnosis, prognosis, and treatment outcome prediction. The aims of the present review are to summarize the published and recently presented data on MPM biomarkers and to identify the prospects for future translational research projects.Among the 'classical' diagnostic biomarkers measured in biological fluids, such as cytokeratins and cell surface antigens, none discriminate patients with MPM from those with other malignancies and nonmalignant diseases. Osteopontin, soluble mesothelin, and megakaryocyte potentiating factor (MPF) appear to be the most promising of the recent biomarkers, but are still subject to some limitations. Osteopontin lacks specificity for mesothelioma, while both soluble mesothelin and MPF lack sensitivity for detecting non-epithelial subtypes. Panels consisting of a small set of biomarkers do not improve the diagnostic yield, and results from molecular profiling are too preliminary to be brought into daily clinical practice. While a large number of biomarkers have been assessed in biological fluids and tumor tissue for their prognostic value, none have had a widespread impact on clinical practice. In contrast, data concerning predictive biomarkers are very limited, even though they are most interesting from the perspective of clinicians.Additional prospective studies, in large and independent samples of patients, with rigorous statistical methodology and standardized laboratory techniques are now warranted to validate and define the precise value of diagnostic and prognostic MPM biomarkers. Future research efforts should focus on biomarkers predictive of the efficacy and toxicity of standard chemotherapy. Translational research should be systematically incorporated into the design of clinical trials assessing new targeted agents in MPM.

Evaluation of 12 antibodies for distinguishing epithelioid mesothelioma from adenocarcinoma: identification of a three-antibody immunohistochemical panel with maximal sensitivity and specificity

We evaluated the sensitivity and specificity of 10 monoclonal and two polyclonal antibodies for distinguishing epithelioid mesothelioma from adenocarcinoma (AdCA) using immunohistochemistry (IHC). The antibodies were directed against the mesothelial-associated antigens mesothelin, calretinin, cytokeratin 5, thrombomodulin, Wilms' tumor-1 (WT-1) gene product and HBME-1, and the nonmesothelial antigens Lewis-Y blood group (antibody BG8), MOC-31, BerEp4, CD15, and carcinoembryonic antigen (CEA) family. The 133 tumors evaluated included 65 malignant epithelioid mesotheliomas, 22 lung AdCAs, 27 ovarian serous carcinomas, 24 breast carcinomas, and five gastric carcinomas. Diagnoses were based on clinical, histologic, ultrastructural, and/or IHC findings. Calretinin had the best sensitivity for mesothelioma (95%), followed by HBME-1 (84%), WT-1 (78%), cytokeratin 5 (76%), mesothelin (75%), and vimentin and thrombomodulin (68%). Thrombomodulin had the best specificity for mesothelioma (92%), followed by cytokeratin 5 (89%), calretinin (87%) vimentin (84%), and HBME-1 (45%). When ovarian carcinomas were excluded from the analysis, the specificity of mesothelin and WT-1 for the diagnosis of mesothelioma increased to 90 and 81%, respectively. The sensitivity of the nonmesothelial antigens for AdCA was organ dependent, with BG8 performing best in the breast cancer group (96%), and BerEp4, BG8, MOC-31 performing best in the lung cancer group (100%). The specificity of the nonmesothelial antigens for AdCA was 98% for BG8 and CEA, 97% for CD15, 95% for BerEp4, and 87% for MOC-31. A novel statistical analysis technique employing logic regression analysis identified a three-antibody immunohistochemical panel including calretinin, BG8, and MOC-31, which provided over 96% sensitivity and specificity for distinguishing epithelioid mesothelioma from AdCA.

Carcinoma in situ of the cystic duct

Cholelithiasis and cholesterolosis associated with carcinoma in situ of the cystic duct epithelium was observed in a male patient. Ultrastructurally, small acini-like lined a thickened, reduplicated basal lamina encompassing a pleiomorphic population of cells, including typical cholecystocytes, a poorly differentiated type, and cells containing modified mucous vesicles with heterogeneous fatty deposits. Even though the etiology of this apparent neoplastic epithelium and of its thickened basal lamina is unclear, it is hypothesized to be the result of an altered control of cell adhesion mechanisms, resulting from a repeated renewal of the typical epithelium abraded by the passage of the stones and the biliary sludge, associated with inflammatory stimuli that accompany cholecystolithiasis. Based on recent studies, it is suggested that investigations of molecular markers in extrahepatobiliary tract lesions and retrospective studies of these archival tissues could clarify the association of these neoplastic changes with other hepato-biliary lesions.

Malignant mesothelioma

Malignant mesothelioma is an aggressive, treatment-resistant tumour, which is increasing in frequency throughout the world. Although the main risk factor is asbestos exposure, a virus, simian virus 40 (SV40), could have a role. Mesothelioma has an unusual molecular pathology with loss of tumour suppressor genes being the predominant pattern of lesions, especially the P16INK4A, and P14ARF, and NF2 genes, rather than the more common p53 and Rb tumour suppressor genes. Cytopathology of mesothelioma effusions or fine-needle aspirations are often sufficient to establish a diagnosis, but histopathology is also often required. Patients typically present with breathlessness and chest pain with pleural effusions. Median survival is now 12 months from diagnosis. Palliative chemotherapy is beneficial for mesothelioma patients with high performance status. The role of aggressive surgery remains controversial and growth factor receptor blockade is still unproven. Gene therapy and immunotherapy are used on an experimental basis only. Patterns identified from microarray studies could be useful for diagnosis as well as prognostication.

Prognostic factors in mesothelioma

Prognostic factors in oncology may help physicians give their patients a prognosis for their disease and thus allow them to make plans for the future. These factors also assist in the selection of patients more likely to benefit from intensive treatments, especially in the context of clinical trials. Recently it has become clear that prognostic factors may have an additional benefit: they may provide insight into the biology of the cancer being studied and lead to improved understanding of the molecular pathogenesis. For malignant mesothelioma, the prognostic scoring systems of the Cancer and Leukemia Group B (CALGB) and European Organization for Research and Treatment of Cancer (EORTC) are the most useful of those currently available. These systems rate performance status, age, histological subtype, weight loss, and hematological parameters as the best prognostic factors for malignant mesothelioma. In the future, biological markers may provide additional information on mesothelioma and will help in prognostication.