The role of a nomogram consisted of routine biochemical tests in increasing the diagnostic accuracy of chromogranin A in detecting patients with neuroendocrine tumors

UVOD I CILJEVI: Kromogranin A (CgA) je tumorskimarker koji se koristi kao dijagnostički i prognostički alat u bolesnika s neuroendokrinim tumorom (NET). Koncentracija CgA u serumu ovisi i o prisustvu brojnih komorbiditeta. Opći cilj rada je analizirati povezanost pojedinih biokemijskih i antropometrijskih parametara kod ispitanika koji nemaju NET te izraditi nomogram kojim bi se povećala dijagnostička točnost CgA u otkrivanju bolesnika s NET-om. ----- METODE: U retrospektivnom istraživanju analizirana su mjerenja CgA tijekom kojih su učinjene i druge biokemijske pretrage te zabilježeni antropometrijski parametri. Kontrolna skupina bili su bolesnici u kojih je učinjenom slikovnom i/ili funkcionalnom dijagnostičkom obradom isključeno postojanje NET-a, a u ispitivanu skupinu uključeni su bolesnici s patohistološkom dijagnozom NET-a koji su u trenutku mjerenja imali aktivnu bolest. Konačno, uključeno je 155 bolesnika u kontrolnu skupinu i 55 bolesnika u ispitivanu skupinu. ----- REZULTATI: CgA je u bolesnika s vrijednošću nomograma 22 CgA nije imao nikakvu dijagnostičku vrijednost. ----- ZAKLJUČAK: Nomogram sačinjen od rutinskih biokemijskih i antropometrijskih parametara može povećati dijagnostičku točnost CgA u otkrivanju bolesnika s NET-om.INTRODUCTION: Chromogranin A (CgA) is a tumor marker which is used as a diagnostic and prognostic tool in patients with neuroendocrine tumors (NET). Falsely elevated serum CgA is associated with the use of proton pump inhibitors, the presence of renal impairment and systemic inflammation. We aimed to investigate which laboratory parameters are independently associated with increasedCgA and to develop a nomogram in order to improve the diagnostic accuracy of CgA in detecting patients with NETs. ----- METHODS: Our retrospective study included 155 subjects (controls) and 55 treatment naïve patients with NET, available data on CgA, other laboratory tests, medical history and anthropometric parameters. A nomogram was developed in a form of a scoring system based on z-score obtained from receiver operating curve analysis for each parameter that was independently associated with CgA. ----- RESULTS: CgA in patients with nomogram values 12-16 and >22 did not have any diagnostic accuracy. On the other hand, 68.9% of the entire study population had an increased diagnostic accuracy of CgA. ----- CONCLUSION: A nomogram consisted of routine biochemical tests may increase the diagnostic accuracy of chromogranin A in detecting patients with neuroendocrine tumors. Further validation studies are needed