Impact of chromogranin A measurement in the work-up of neuroendocrine tumors

Since the development of the first immunoassay for circulating chromogranin A in 1984, a lot of studies have evaluated its clinical impact in neuroendocrine tumors. Initially studied in pheochromocytoma patients, the clinical impact of chromogranin A has rapidly extended to most neuroendocrine tumours, sometimes in combination with other eutopic or ectopic secretions. In our experience, CgA demonstrates a variable sensitivity between NET primary and a high specificity. Our results suggest that CgA should be routinely screened in foregut-derived NET and abandoned in the routine screening of medullary thyroid carcinoma. In addition, in phaeochromocytoma and ileum-NET patients, CgA demonstrates a comparable sensitivity with urinary reference markers and its impact on the follow-up will form a key point when recommending routine screening. Both tumor burden and secretory activity should be taken into account when interpreting CgA results.