Anita  Minopoli,Bruna  Grilli,Chiara De  Divitiis,Ernesta Cavalcanti,Gaetano  Corso,Luigi  Russo,Monica  Gelzo,Monica  Capozzi,Salvatore  Tafuto,Vittoria  Barchiesi,
Implementation of a Hplc Method for the Evaluation of Urinary 4-Hydroxyphenylacetic Acid in Patients with Neuroendocrine Tumors
Clinical Oncology and Research
2019
2613-4942
http://dx.doi.org/10.31487/j.COR.2019.5.16
https://www.sciencerepository.org/implementation-of-a-hplc-method-for-the-evaluation-of-urinary_COR-2019-5-116 
Abstract: Neuroendocrine tumors (NETs) are a group of neoplasms that originate from neuroendocrine cells. They
can occur in various anatomic locations, most commonly in gastro intestinal tract, lungs and pancreas. In
NETs associated to the carcinoid syndrome, the tumor cells produce hormones, such as serotonin. 5-
Hydroxyindoleacetic acid (5-HIAA), the main metabolite of serotonin, represents an useful urinary
biomarker which is routinely determined to investigate and monitor patients with carcinoid syndrome by
high performance liquid chromatography (HPLC). The chromatographic profile obtained by a standardized
commercial HPLC method shows also the presence of 4-hydroxyphenylacetic acid (pHPAA), which is
physiologically excreted in urine of healthy people. Interestingly, in some NETs profiles we observed a high
pHPAA peak that was not resolved from 5-HIAA peak at higher concentrations of one or both metabolites.
Therefore, we implemented and validated a HPLC method for the determination of urinary pHPAA
improving the chromatographic separation between 5-HIAA and pHPAA. In addition, we determined
pHPAA levels in 40 urine samples from patients with NETs that resulted significantly higher compared to
healthy subjects. Our preliminary results showed that the modified HPLC method allows to quantify
accurately pHPAA that could represent a useful marker, together with 5-HIAA, for the management of
patients with NETs.Keywords: Neuroendocrine tumors, carcinoid Syndrome, 4-hydroxyphenylacetic acid, HPLC