Chromogranin A as an alternative to 5-hydroxyindoleacetic acid in the evaluation of symptoms during treatment of patients with neuroendocrine Tumors.

Background: Urinary 5-HIAA excretion is a well-known marker in neuroendocrine tumors (NETs), but it has a low sensitivity and the 24-hour collection is inconvenient for patients. Chromogranin A (CgA) is a promising marker, but a thorough evaluation during follow-up is still lacking.
Methods: 39 patients with metastatic gastrointestinal NETs were monitored during treatment with the long-acting octreotide SandostatinLAR. A comparison was made between serum CgA and urinary 5-HIAA in relation to quality of life (HRQL) assessed by the EORTC QLQ-C30 questionnaire, supplemented with questions specific to carcinoid symptoms. Survival analyses were performed to examine the association between the markers and survival time.
Results: Correlations were found between CgA and physical functioning (p = 0.01) and quality of life (p = 0.03), while no significant correlations were observed between 5-HIAA levels and any of the self-reported health outcomes. Cox regression showed an association between CgA levels and survival time (p = 0.02), while no significant association was observed between 5-HIAA levels and survival time.
Conclusion: Stronger correlations of CgA compared to 5-HIAA with physical functioning and wellbeing, the convenience of measuring in blood, as well as the prognostic value of CgA for survival, makes CgA the recommended marker in the management of patients with metastatic NETs.