Clinical Trial: Specificity of Elevated Plasma EM66 Levels in Pheochromocytoma

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

Official Title: Clinical Application of New Pheochromocytoma Markers: INSERM Pilot Study of the Specificity of Elevated Plasma EM66 Concentrations in Patients With Pheochromocytoma or Paragangli

Brief Summary: Pheochromocytoma or paraganglioma are tumors generating hypertension as a symptom. Different biological tests are currently available to diagnose these tumors. However, they all lack specificity since they do not distinguish cases of hypertension without pheochromocytoma or paraganglioma. To improve the diagnostic specificity of these tumors, the investigators are testing a new marker called EM66.

Detailed Summary: Neuroendocrine tumors (NT) correspond to neoplasms that develop from endocrine and neuroendocrine cells scattered throughout the body. They are characterized by the occurrence, in their cytoplasm, of dense-core secretory vesicles containing hormones, neuropeptides and acidic proteins such as granins. The diversity of NT (from hypophysis, pancreas, adrenal, gastrointestinal tract) makes very difficult the identification and evaluation of the different types of tumors by the diagnostic and prognostic tools currently available. We have thus established a research program aimed at identifying new biological markers for the detection, the prognosis and the follow-up of NT by seeking in tumor and plasma samples of patients, granin-derived peptides. Our program was initiated on one type of NT : pheochromocytoma. These neoplasms correspond to tumoral chromaffin cells mainly originating from the adrenal medulla. It is considered that 10 % of pheochromocytoma patients will develop metastases and, currently, except in the presence of metastases, there are no means to predict malignancy of the tumor. We setup a radioimmunoassay of EM66 (a secretogranin II-derived peptide) that allowed us to demonstrate that (i) plasma concentrations of the peptide are significantly elevated in pheochromocytoma patients, (ii) combined with other biological tests EM66 measurement increase the diagnostic sensitivity for these neoplasms, (iii) after surgical removal of the tumor, plasma EM66 concentrations rapidly return to basal level and, (iv) intra-tumoral EM66 concentrations are higher in benign than in malignant pheochromocytomas (Yon et al., 2003, Guillemot et al., 2006). These results reveal that EM66 constitutes a novel tool for the diagnosis, prognosis and follow-up of pheochromocytoma. In the frame of a clinical use of an EM66 measurement test, it is necessary to evaluate the specificity of this marker. For instance, renal deficiency, hypergastrinemia, reduction of renal clearance, type A
Sponsor: University Hospital, Rouen

Current Primary Outcome: Plasma EM66 [ Time Frame: two years ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Plasma Chromogranin A levels [ Time Frame: before treatement ]

Original Secondary Outcome: Same as current

Information By: University Hospital, Rouen

Dates:
Date Received: November 17, 2009
Date Started: November 2008
Date Completion:
Last Updated: June 18, 2014
Last Verified: June 2014