Prognostic Factors in Curative Resected Locoregional Small Intestine Neuroendocrine Neoplasms

Background Small intestinal neuroendocrine neoplasms (SI-NEN) are rare, and only about 40% of patients are diagnosed without distant metastases. Aim of the study was to identify prognostic factors in patients with potentially curative resected locoregional SI-NEN. Methods Patients with curative resected locoregional SI-NEN (ENETS stages I-III) were retrieved from a prospective data base. Demographic, surgical and pathological data of patients with and without disease recurrence were retrospectively analyzed using univariate and multivariate analysis. Results In a 20-year period, 65 of 203 (32%) patients with SI-NEN were operated for stages I–III disease. Thirty-eight (58.5%) patients were men, and the median age at surgery was 59 (range 37–87) years. After median follow-up of 65 months, 14 patients experienced disease relapse median 28.5 (range 6–122) months after initial surgery, of which 2 died due to their disease. Multivariate analysis revealed age ≥ 60 years (HR = 6.41, 95% CI 1.38–29.67, p = 0.017), tumor size ≥ 2 cm (HR = 26.54, 95% CI 4.46–157.62, p < 0.001), lymph node ratio > 0.5 (HR 7.18, 95% CI 1.74–29.74, p = 0.007) and multifocal tumor growth (HR = 6.98, 95% CI 1.66–29.39, p = 0.008) as independent negative prognostic factors and right hemicolectomy compared to segmental small bowel resection (HR = 0.04, 95% CI 0.01–0.24, p < 0.001) as independent protector against recurrence. Conclusion Patients with locoregional SI-NEN with an age ≥ 60 years, tumor size ≥ 2 cm, lymph node ratio > 0.5 and multiple small bowel tumor foci have an increased risk for recurrence and might benefit from adjuvant treatment. In contrast, right hemicolectomy of ileal SI-NEN seems to reduce the risk of recurrence.