Neurokinin A levels predict survival in patients with stage IV well differentiated small bowel neuroendocrine neoplasms

Background: Recent European investigations have shown that persistently elevated (>50 pg/mL) plasma neurokinin A levels are associated with poor short-term survival in patients with midgut neuroendocrine neoplasms. We hypothesized that American patients with persistently elevated plasma neurokinin A levels (>50 pg/mL) will also have a poor short-term survival. Methods: Serial plasma neurokinin A levels were collected from the charts of 180 patients with metastatic midgut neuroendocrine neoplasms. Patients were grouped according to their plasma neurokinin A values, and survival rates were calculated. Group 1 had plasma neurokinin A levels <50 pg/mL. Group 2 at one point had plasma neurokinin A levels >50 pg/mL, but are currently <50 pg/mL. Group 3 had plasma neurokinin A values consistently >50 pg/mL. Results: Group 1 patients (n = 143) have not reached their median survival and have a 24-month survival of 93%. Thirteen of 14 (93%) group 2 patients are currently alive. Group 3 patients (n = 23) had a median survival of 20 months and a 24-month survival of 48%. Conclusion: Patients with midgut neuroendocrine neoplasms who have serial plasma neurokinin A levels <50 pg/mL have an excellent short-term prognosis, while patients with plasma neurokinin A levels >50 pg/mL have a poor short-term prognosis.