Limited value for urinary 5-HIAA excretion as prognostic marker in gastrointestinal neuroendocrine tumours

Abstract

Urinary 5-HIAA excretion >10× ULN is a negative predictor for OS. However, when added to other biomarkers and grading, it is no longer a predictor for OS. Therefore, it should only be determined to assess carcinoid syndrome and not for prognostic value.