Surgical Management of Small Bowel Neuroendocrine Tumors: Specific Requirements and Their Impact on Staging and Prognosis.

BACKGROUND: Small bowel neuroendocrine tumors (SB-NETs) are characterized by two main features: they usually are metastatic at diagnosis and multiple in 30 % of cases. As such, SB-NETs require specific surgical management. This retrospective study examined local recurrence, survival, and prognosis of SB-NETs after adapted surgery.

METHODS: All consecutive patients with SB-NETs who underwent resection of at least one primary tumor between 1 January 2000 and 1 January 2013 were analyzed. The preoperative morphologic workup, histologic classification, and metastatic lymph node (LN) ratio (LNs involved/removed) were recorded.

RESULTS: The study enrolled 107 patients, 35 (33 %) of whom had multiple SB-NETs (range 1-44; mean 3.1). Preoperative imaging and perioperative surgical examination missed 61 and 33 % of SB-NETs, respectively, in contrast to pathologic examination. Of the 107 patients, 43 % had carcinoid syndrome, 70 % had metastatic disease, and 90 % had LN involvement. The median number of LNs retrieved was 12 (range 1-69). The LN ratio (LNs involved/removed) was 0.25. The highest tumoral grades were G1 (in 61 % of patients) and G2 (in 37 % of patients). Of the 107 patients, 13 (12 %) had local LN recurrence. The rate of LN recurrence-free survival at 5 years was 88 %. The median overall survival (OS) time was 128 months (range 91-165 months). In the multivariate analysis, high chromogranin A (CgA) levels and peritoneal carcinomatosis were significantly associated with shorter OS.

CONCLUSIONS: Systematic palpation of the entire small bowel detects more multiple NETs than preoperative imaging. Systematic surgery with extensive LN resection is associated with low local recurrence. High CgA levels and carcinomatosis are linked with shorter survival.