Resumen
This large single-center study of 615 patients with small intestinal neuroendocrine tumors (siNET) showed that the risk of recurrence after intended radical surgery was high with a recurrence-free survival rate of 40% after 10 years follow-up, and that late recurrencies were frequent. For cases with disseminated disease, the median disease specific survival was around 7 years. Tumor proliferation expressed by Ki-67 index was identified as a prognostic factor whereas proliferation expressed by WHO grade did not predict prognosis. In conclusion, radical intended surgery recurrence rates were high thereby justifying long-term follow-up. Proliferation expressed by Ki-67 index as a continuous variable, rather than grouped according to WHO grading, was an independent prognostic factor for both recurrence-free survival and disease-specific survival supporting the need for reevaluation of the existing grading system.