A single fasting plasma 5-HIAA value correlates with 24-hour urinary 5-HIAA values and other biomarkers in midgut neuroendocrine tumors (NETs)

Pancreas. 2013 Apr;42(3):405-10. doi: 10.1097/MPA.0b013e318271c0d5.


Objectives: 5-Hydroxyindoleacetic acid (5-HIAA) is used for the evaluation of neuroendocrine tumors (NETs) but currently requires a 24-hour urine collection.

Methods: We developed a gas chromatography mass spectroscopy-based plasma 5-HIAA assay. We compared 24-hour urine 5-HIAA values against plasma 5-HIAA values in 115 mixed-variety patients with NETs and in a subset of 72 patients with only small bowel NETs. We also compared the information gained from urinary and plasma 5-HIAA values with other biomarkers of midgut NET activity to determine the plasma assay's clinical implications.

Results: In a group of 115 patients with all types of NETS, in a subset of patients with midgut NET and in a subgroup of midgut NETS with liver metastasis, the correlation between the urine and fasting plasma 5-HIAA values were statistically significant (P ≤ 0.0001). Comparison of the proportion of normal or abnormal urinary and plasma 5-HIAA values to the proportion of chromogranin, serotonin, neurokinin, or pancreastatin values that were in the normal or abnormal range yielded essentially identical information.

Conclusions: Plasma fasting 5-HIAA values are proportional to urinary 5-HIAA values and yielded identical clinical correlation with other biomarkers.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers / analysis*
  • Biomarkers / blood
  • Biomarkers / urine
  • Chromogranin A / analysis
  • Disease Progression
  • Fasting / blood
  • Female
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Hydroxyindoleacetic Acid / analysis*
  • Hydroxyindoleacetic Acid / blood
  • Hydroxyindoleacetic Acid / urine
  • Intestinal Neoplasms / blood
  • Intestinal Neoplasms / pathology*
  • Intestinal Neoplasms / urine
  • Liver Neoplasms / blood
  • Liver Neoplasms / secondary
  • Liver Neoplasms / urine
  • Male
  • Middle Aged
  • Neuroendocrine Tumors / blood
  • Neuroendocrine Tumors / pathology*
  • Neuroendocrine Tumors / urine
  • Neurokinin A / analysis
  • Pancreatic Hormones / analysis
  • Prognosis
  • Reference Values
  • Sensitivity and Specificity
  • Serotonin / analysis


  • Biomarkers
  • Chromogranin A
  • Pancreatic Hormones
  • pancreastatin
  • Serotonin
  • Hydroxyindoleacetic Acid
  • Neurokinin A