BACKGROUND:We aimed to identify prognostic blood biomarkers using proteomics-based approaches in malignant pleural mesothelioma (MPM).METHODS:Plasma samples from 12 MPM patients were used for exploratory mass spectrometry and ELISA analyses. The significance of secreted protein acidic and rich in cysteine (SPARC) was examined in sera from a Dutch series (n=97). To determine the source of the circulating SPARC, we investigated SPARC expression in MPM tumours and healthy controls, as well as the expression and secretion from cell lines and xenografts.RESULTS:Secreted protein acidic and rich in cysteine was identified as a putative prognostic marker in plasma. Validation in the Dutch series showed that the median survival was higher in patients with low SPARC compared with those with high SPARC (19.0 vs 8.8 months; P=0.01). In multivariate analyses, serum SPARC remained as an independent predictor (HR 1.55; P=0.05). In MPM tumour samples, SPARC was present in the tumour cells and stromal fibroblasts. Cellular SPARC expression was higher in 5 out of 7 cell lines compared with two immortalized mesothelial lines. Neither cell lines nor xenograft tumours secreted detectable SPARC.CONCLUSIONS:Low circulating SPARC was associated with favourable prognosis. Secreted protein acidic and rich in cysteine was present in both tumour cells and stromal fibroblasts; and our in vitro and in vivo experiments suggest that stromal fibroblasts are a potential source of circulating SPARC.

Aim: We investigated the association of delay in diagnosis with stage, grade, symptoms, primary site of the tumor and survival in patients with well-differentiated (G1G2) neuroendocrine tumor (NET). Patients and Methods: We collected data of 227 patients who were referred to the NKI-AVL and Westfriesgasthuis between 2003 and 2009. The date of onset and nature of first symptoms, as well as the date of NET diagnosis were reported in order to calculate the delay in diagnosis. Univariate linear regression analyses and Kaplan-Meier curves were performed to examine the association between delay in diagnosis, patient characteristics and survival. Results: The median delay in diagnosis was 16 (0-296) months. There was no association between delay and survival and stage of disease. Patients with a NET from the small bowel showed a longer delay than from other sites. Patients with a G1NET had longer delays than patients with G2NET. Patients with a longer delay were more likely to have psychological problems. Conclusion: Although the delay in diagnosis in patients with NET can be long, it did not affect survival. Patients with a long delay frequently have psychological symptoms. As a long delay could have adverse effects on quality of life, continued efforts to establish an early diagnosis are needed.

The complexity of the clinical management of neuroendocrine neoplasia (NEN) is exacerbated by limitations in imaging modalities and a paucity of clinically useful biomarkers. Limitations in currently available imaging modalities reflect difficulties in measuring an intrinsically indolent disease, resolution inadequacies and inter-/intra-facility device variability and that RECIST (Response Evaluation Criteria in Solid Tumors) criteria are not optimal for NEN. Limitations of currently used biomarkers are that they are secretory biomarkers (chromogranin A, serotonin, neuron-specific enolase and pancreastatin); monoanalyte measurements; and lack sensitivity, specificity and predictive capacity. None of them meet the NIH metrics for clinical usage. A multinational, multidisciplinary Delphi consensus meeting of NEN experts (n = 33) assessed current imaging strategies and biomarkers in NEN management. Consensus (>75%) was achieved for 78% of the 142 questions. The panel concluded that morphological imaging has a diagnostic value. However, both imaging and current single-analyte biomarkers exhibit substantial limitations in measuring the disease status and predicting the therapeutic efficacy. RECIST remains suboptimal as a metric. A critical unmet need is the development of a clinico-biological tool to provide enhanced information regarding precise disease status and treatment response. The group considered that circulating RNA was better than current general NEN biomarkers and preliminary clinical data were considered promising. It was resolved that circulating multianalyte mRNA (NETest) had clinical utility in both diagnosis and monitoring disease status and therapeutic efficacy. Overall, it was concluded that a combination of tumor spatial and functional imaging with circulating transcripts (mRNA) would represent the future strategy for real-time monitoring of disease progress and therapeutic efficacy.

Serum markers have been tested in patients with malignant effusions for their ability to differentiate malignant pleural mesothelioma from other causes. So far no single tumor marker has been identified that differentiates mesothelioma from other causes. We therefore combined three different serum markers and report our findings in a series of patients with different pleural malignancies and healthy controls. A retrospective analyses of 179 patients and 50 healthy controls was performed. Seventy-four patient had a confirmed mesothelioma, and 110 patients had non small cell lung cancer of whom 56 with an adenocarcinoma. Soluble Mesothelin Related Protein (SMRP), Cyfra 21.1 and Carcino Embrionic Antigen (CEA) were tested in serum at diagnosis of patients presenting with a suspected pleural malignancy. Cyfra 21.1 was able to discriminate healthy from any thoracic malignancy with a sensitivity of 65% and specificity of 96%. The combination of CEA and SMRP was most accurate in differentiating mesothelioma from NSCLC (area under receiver operating characteristics curve 0.94, 95% CI 0.90-0.97) and could thus identify 152 of 179 (85%) cases. By using 2 serum markers (CEA and SMRP) we are able to discriminate mesothelioma from NSCLC with high sensitivity, while Cyfra 21.1 is useful in the discrimination of normal vs. malignancy.

OBJECTIVE:The diagnosis of leptomeningeal metastases (LM) is based on clinical symptoms, magnetic resonance imaging (MRI) of brain and spine and cytological analysis of cerebrospinal fluid (CSF). The clinical picture of LM is highly variable and both cytological CSF analysis and contrast-enhanced MRI are limited in sensitivity. More sensitive tools are needed to diagnose LM. We measured a profile of proteins involved in adhesion and inflammation in the CSF of LM and control patients and determined their potential diagnostic value for LM.PATIENTS AND METHODS:Using Multiplex Immuno-Assay (MIA), the CSF concentrations of nine soluble adhesion molecules, cyto- and chemokines were measured in patients with cytologically proven LM (n = 57) and control patients with a systemic malignancy (n = 20), aseptic/viral meningitis (n = 11) or other (non-)neurological diseases (n = 19).RESULTS:We found high CSF levels of soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), soluble Intercellular Adhesion Molecule-1 (sICAM-1), Interleukin-8 (IL-8), Pulmonary and Activation Regulated Chemokine (PARC), Interleukin-18 (IL-18) and Interferon-gamma inducible protein (IP-10) in patients with LM. The CSF protein profile in LM patients differed significantly from the profile found in control patients. Multivariate logistic regression and ROC analysis showed that the MIA-measured CSF protein profile has an additive discriminating value for LM above standard CSF parameters. A combination of total protein, glucose, IL-8, PARC and IP-10 CSF levels proved to be most discriminative between LM and non-LM patients.CONCLUSION:Our results warrant a prospective study to determine whether a CSF protein profile, including IL-8, PARC and IP-10 has diagnostic value compared with CSF cytology, the golden standard for LM.