Prognostic factors influencing survival in small bowel neuroendocrine tumors with liver metastasis.

Abstract

e15688 Background: Management of liver metastasis in patients with small bowel neuroendocrine tumors (SBNET) remains unclear. Complete surgical resection improves long term survival however factors that influence overall prognosis are not clear. Methods: Database review identified 301 patients diagnosed with SBNET from 1990 to 2013. Only patients with known liver metastasis who underwent resection of the primary tumor were included. Outcomes among patients who underwent complete surgical resection, incomplete debulking of liver metastasis, and resection of the primary tumor alone were compared. The Kaplan-Meier method was used for survival estimates and Cox regression was used to identify predictors of death. Results: 111 patients met study criteria. Median age was 59 years (range 16-80); 49% were male. The terminal ileum (47/111, 42%) was the most common primary tumor location. The median number of liver lesions was 8.5 (range 1-31) and median lesions resected was 1 (range 0-31). In addition to resection of the primary tumor, 36 patients (32%) had no liver resection (NR), 41 (36.9%) had complete resection of liver disease (R0) and 34 (30%) had incomplete resection of liver metastasis (R1). 58 patients (36%) had one or more wedge resections, 12 (10.8%) underwent segmentectomy and 5 (4.5%) had a lobectomy. 33 (29.7%) patients underwent post-operative chemoembolization, 25 (22.5%) had radioembolization and 23 (20.7%) had radiofrequency ablation. The R1 group differed from the R0 group in median size of primary tumor (2.5 cm R1 vs 1.6 cm R0, p = 0.05) and median number of positive lymph nodes (5.0 R1 vs 3.0 R0, p = 0.05). The 5-year OS was 80.9%, 81.1% and 100% for NR, R1 and R0 groups respectively (p = 0.01). 10-year OS did not differ between groups (72.8% NR vs 81.1% R1vs 82.5% NR, p = 0.31). Cox regression showed post-operative administration of chemotherapy (HR = 3.68, p < 0.01) and higher tumor grade (HR = 18.4, p = 0.02) increased risk of death. Conclusions: In patients with SBNET with liver metastasis, higher tumor grade and post-operative chemotherapy increased risk of death. However, resection of the primary tumor along with liver metastasis improves the 5-year OS with complete cytoreduction providing the most benefit.