E. W. Cytryn1, J. J. Aalberg1, D. Dolan1, C. M. Divino1 1Icahn School Of Medicine At Mount Sinai,Division Of General Surgery, Department Of Surgery,New York, NY, USA
Introduction: The incidence of small intestinal neuroendocrine tumors (siNETs) in the US has been increasing over the past 20 years. The vast majority of these are diagnosed in older adults with a median age near 68. However, there is little in the current literature that outlines a definitive direction of treatment in these patients. The aim of this study was to determine whether elderly patients with siNETs who undergo surgery have different cancer-specific and overall survival outcomes than those who do not. We hypothesized that patients who underwent surgery would have better survival outcomes.
Methods: We identified patients 65 years and older diagnosed with siNETs from 1998-2014 in the Surveillance, Epidemiology, and End Results (SEER) database. To determine the risk factors associated with overall survival, we performed chi-square tests. Kaplan-Meier analysis was also used to estimate overall and cancer-specific survival functions for both study cohorts and log-rank tests were used to compare the curves. The effect of surgical intervention on overall and cancer-specific survival was further examined using a multivariable inverse probability weighted propensity scored Cox Proportional-Hazard model.
Results: We found 4,732 patients with siNETs, 3,877 (81.93%) of whom underwent cancer-directed surgery. In univariate analysis, surgery was found to be significantly associated with an increase in 1-year (80.99% vs. 68.77%; p<.0001) and 5-year overall survival (38.69% vs. 27.25%; p<.0001). Age, primary site, histologic type, grade, and stage were also found to be significantly associated with increased 1-year and 5-year overall survival. Log-rank tests performed on the Kaplan-Meier survival functions indicated a significant increase in overall survival (p<.0001) and cancer-specific survival (p<.0001) for patients receiving surgery. After propensity scoring, patients who underwent surgical resection were found to have a significantly reduced hazard of cancer-specific death (HR: 0.475; 95% CI: 0.422-0.535; p<.0001) as well as overall death (HR: 0.659; 95% CI: 0.611-0.711; p<.0001).
Conclusion: Elderly patients who underwent surgical resection of siNETs had better cancer-related and overall survival than patients who did not. Though surgery can be contraindicated in older patients, the results of this study provide support for the surgical management of siNETs and suggest this intervention as the standard of treatment.