Raised circulating Neurokinin A predicts prognosis in metastatic small bowel neuroendocrine tumours. Lowering Neurokinin A indicates improved prognosis

Background Assessing prognosis is important in patients with neuroendocrine tumours of the small bowel as disease progression and survival is variable. We previously identified raised Neurokinin A as an independent indicator of poor prognosis and have shown that prognosis worsens when circulating Neurokinin A rises ≥50 ng/L. In the present study we have examined survival in relation to Neurokinin A concentrations. Methods Patients in whom Neurokinin A rose ≥50 ng/L between January 1989 and December 2010 were identified. All circulating Neurokinin A concentrations were recorded and survival was followed up to 31 December 2014 or to death. Results Median survival, from the date when Neurokinin A was first ≥50 ng/L was 11.1 (2.0–117.8) months if Neurokinin A remained ≥50 ng/L and 72.4 (4.8–152.6) months when Neurokinin A was reduced below 50 ng/L and controlled below that concentration for ≥3 months (P