Evaluation of chromogranin A expression in patients with non-neuroendocrine tumours.

Background: Chromogranin A (CgA) is well established as a serum marker for neuroendocrine tumours and has also been associated with some non-neuroendocrine tumours, suggesting a possible role for somatostatin analogues such as octreotide in the treatment of these tumours.

Objective: The aim of this study was to measure plasma CgA levels in patients with various non-neuroendocrine tumours in order to identify those patients who might benefit from octreotide therapy.

Methods: Plasma CgA levels were tested in 151 patients with metastatic non-neuroendocrine tumours. Patients with highly elevated levels were assessed by OctreoScan scintigraphy to determine their somatostatin receptor status, and those with positive results were offered treatment with the somatostatin analogue octreotide, 20 mg every 4 weeks, and followed up every 3 months.

Results: CgA levels were elevated (>18 U/L) in 34/72 patients with breast cancer, 11/21 with lung cancer, 10/28 with gastrointestinal cancer, 7/12 with gynaecological cancer, 6/9 with genitourinary cancer, 5/5 with haematological cancer, and 3/4 with head and neck cancer. Eight patients with CgA levels >150 U/L underwent scintigraphy, five of whom (two colorectal, two prostate, one non-small cell lung cancer [NSCLC]) showed positive results and received treatment with octreotide. Follow-up for a mean 12-16 months showed improvements in biochemical parameters, cenesthesis and quality of life.

Conclusion: CgA levels were found to be elevated in approximately 50% of patients with non-neuroendocrine tumours. Further studies are required to determine the value of CgA as a marker for non-neuroendocrine tumours and the role of somatostatin analogues as a treatment for these tumour types.