Management of Neuroendocrine Tumor Liver Metastases: Long-Term Outcomes and Prognostic Factors from a Large Prospective Database

Background. Liver-directed therapies have been used to treat neuroendocrine liver metastases (NELM) for both symptomatic improvement and tumor growth control. We reviewed our experience with NELM to investigate the outcomes of available treatment modalities and to identify prognostic factors for survival. Methods. We identified all patients with NELM, who were managed at our institution, from a prospectively collected institutional database. Overall survival (OS) was determined for each treatment modality. Results. Between 2003 and 2010, we identified 939 patients with neuroendocrine tumors, of whom 649 patients had NELM. The primary tumor site was the small intestine in 245 patients (38%) and pancreas in 194 patients (30%). With a median follow-up of 44 months, the median, 5 and 10 year OS for each treatment group was as follows: hepatic resection (n = 58, 9%), 160 months, 90%, 70%; radiofrequency ablation (n = 28, 4%), 123 months, 84%, 55%; chemoembolization (n = 130, 20%), 66 months, 55%, 28%; systemic therapy (n = 316, 49%), 70 months, 58%, 31%; and observation (n = 117, 18%), 38 months, 38%, 20%. Age [hazard ratio (HR) 1.0, p < 0.001), small bowel primary site (HR 0.5, p < 0.001), hepatic resection (HR 0.3, p = 0.001), well-differentiated tumors (HR 0.3, p < 0.001), alkaline phosphatase within normal limit (WNL) (HR 0.4, p < 0.001), and chromogranin A WNL (HR 0.5, p < 0.001) were significant independent prognosticators for OS. Conclusions. This series represents one of the largest single-institution studies of NELM reported. We found that hepatic resection was associated with highly favorable OS. Our observations support hepatic resection in appropriately selected patients.