Biomarkers predict outcomes following cytoreductive surgery for hepatic metastases from functional carcinoid tumors

Background: Cytoreductive therapy for metastatic carcinoid provides symptomatic relief and improvement in overall survival. We evaluated whether CgA and 5HIAA could predict symptomatic relief and control of disease progression after cytoreductive surgery. Methods: We retrospectively reviewed 70 patients who underwent cytoreductive surgery for neuroendocrine hepatic metastases between 1996 and 2005. Twenty-two patients had pre and post-operative CgA and/or 5HIAA levels measured. Reduction of biomarkers following cytoreduction was correlated with patient symptoms and progression of disease following surgery. Results: Our study consisted of 14 males and 8 females with a mean age of 55 (+/-12 years). Median follow-up was 18 months (range 5-64 months). Six patients (26.1%) had complete (R0) cytoreduction, while 4 (17.4%) and 13 (56.5%) had microscopic (R1) and gross (R2) disease remaining. All patients reported improvements in their symptoms, with 12 (54.5%) reporting complete resolution (CR) and 10 (45.5%) reporting partial resolution (PR). Reduction of CgA of >= 80% was highly predictive of complete resolution of symptoms (P = 0.007) and stabilization of disease (P = 0.034). Reduction of 5HIAA levels of >= 80% (or normalization) was predictive of symptomatic relief, but not progression of disease (P = 0.026 and P = 0.725). Five of six patients who had R0 resections had CR and were free of disease at last follow-up (median 24.5 months, range: 11-48, P = 0.002). Conclusions: We conclude that >= 80% reduction in CgA level following cytoreductive surgery for carcinoid tumors is predictive of subsequent symptom relief and disease control. Substantial reduction in CgA is associated with improved patient outcomes, even after incomplete cytoreduction.