Background: Small bowel neuroendocrine tumors (SB-NET) frequently metastasize to regional lymphatic or distant sites. Although most prognostication of SB-NET focuses on lymph node involvement, findings from studies of neuroendocrine tumors from other primary sites have suggested that preoperative serum chromogranin-A (CgA) levels may provide a more accurate metric.
Methods: Using the National Cancer Database (2004-2016), we analyzed patients with locoregional SB-NET who underwent curative resection including an adequate lymphadenectomy (n = 1,274). A statistically optimized cut-point was used to dichotomize CgA cohort based on preoperative serum CgA levels.
Results: We determined that a CgA ≥139 ng/mL identified patients with significantly shorter estimated mean overall survival (6.6 years vs 7.6 years, log-rank P = .00001). These patients were also older (63 vs 57 years, P < .001) and had higher rates of poorly differentiated tumors (2.1% vs 0.7%, P = .04) or primary tumors >1 cm (88.2% vs 79.2%, P = .001). Clinical features associated with shorter overall survival included preoperative CgA ≥139 ng/mL (HR = 2.19, 95% CI 1.22-3.92; P = .009), age at diagnosis (HR = 1.06, 95% CI 1.03-1.09; P < .001), Charlson-Deyo score ≥2 (HR = 3.93, 95% CI 1.71-9.01; P = .001), and poorly differentiated tumors (HR = 11.22, 95% CI 4.16-30.24; P < .001). Neither lymph node metastasis nor T-stage were independently associated with shorter overall survival in patients with locoregional SB-NET.
Conclusion: Elevated preoperative serum CgA is an adverse prognostic marker associated with shorter overall survival in patients with locoregional SB-NET.
Published by Elsevier Inc.