The diagnostic and prognostic value of elevated proGRP levels in well- and moderately differentiated neuroendocrine tumors

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Introduction: Chromogranin A (CgA) is the most frequently used marker in well- (grade 1) and moderately (grade 2) differentiated NETs. Although CgA is a more sensitive marker than the 5-HIAA, which was widely used until the last decade, CgA has some limitations. False-positively elevated CgA may occur in renal impairment, atrophic gastritis and during treatment of proton-pump inhibitors. Progastrin-releasing peptide (proGRP) was recently reported as a promising tumor marker for small cell lung cancer. Limited data suggests that ProGRP may be a potential tumor marker in NE tumors.

Aim(s): To investigate the diagnostic and prognostic value of proGRP in addition to CgA in well- and moderately differentiated NETs.

Materials and methods: Two-hundred and eighty-five patients diagnosed with NET (247 well- and 38 moderately differentiated), who were referred to the Netherlands Cancer Institute between 1994 and 2009, were eligible for this retrospective study. Blood was taken before starting treatment in our institute. CgA was measured by means of a solid-phase immunoradiometric assay, the CGA-RIACT kit. The ARCHITECT ProGRP assay is a chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination of ProGRP on the ARCHITECT i System. In this study, cut-off levels for CgA were 100 µg/l and for proGRP 300 ng/l.

Conference: 7th Annual ENETSConcerence (2010)

Presenting Author:

Authors: Korse C, Bonfrer J, van den Heuvel M, van Velthuysen M, Vincent A,

Keywords: Well- and moderately differentiated neuroendocrine tumors, proGastrin Releasing Peptide, chromogranin A, lung tumors,