Survival outcomes and surgical intervention of small intestinal neuroendocrine tumors: a population based retrospective study

// Lunpo Wu 1, 2 , Jianfei Fu 3 , Li Wan 1, 2 , Jie Pan 4 , Sanchuan Lai 2, 5 , Jing Zhong 1, 2 , Daniel C. Chung 6 , Liangjing Wang 1, 2 1 Department of Gastroenterology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China 2 Institution of Gastroenterology, Zhejiang University, Hangzhou, Zhejiang Province, China 3 Department of Oncology, Zhejiang University Jinhua Hospital, Jinhua, Zhejiang Province, China 4 Department of Endocrinology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China 5 Department of Gastroenterology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, Zhejiang Province, China 6 Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA Correspondence to: Liangjing Wang, email: Wanglj76@hotmail.com Keywords: small intestine, neuroendocrine tumors, prognostic factors, surgical management, SEER Received: September 26, 2016     Accepted: November 08, 2016     Published: November 26, 2016 ABSTRACT Background: Small intestinal neuroendocrine tumors (SiNETs) without distant metastasis typically behave in an indolent manner, but there can be heterogeneity. We aimed to define the survival outcomes and impacts of surgical intervention. Methods: A retrospective cohort study was conducted by using data from the Surveillance, Epidemiology, and End Results (SEER) database. Clinicopathologic features were analyzed in 4407 patients between 2000 and 2012. The cancer specific survival (CSS) was calculated by the Kaplan-Meier method. Multivariable Cox regression models with hazard ratios (HRs) were constructed to analyze survival outcomes and risk factors. Results: The adjusted incidence of early SiNETs is 1.3/100,000. Tumors are most commonly located in the ileum and are small (≤ 2 cm). The 5-year and 10-year CSS rates were 95.0% and 88.5%, respectively. Age > 50 years, large tumor size (> 2cm), poor differentiation, advanced T classification, and absence of surgical treatment were independent predictors of poor survival. Stratified analysis indicated that surgery significantly improved survival in patients that were white (HR, 0.45), > 50 years old (HR, 0.61), had duodenal tumors (HR, 0.43), large tumors (> 2cm) (HR, 0.32), advanced T classification (T3: HR, 0.29; T4: HR, 0.18) or well differentiation (HR, 0.55). There was no significant survival difference between local resection and radical resection ( P =0.884). Conclusions: Early SiNETs have a favorable prognosis. Surgical resection may improve outcomes, particularly in older patients and those with large tumors. More aggressive resections couldn’t improve outcomes.