Relationship between Primary Tumor Resection for Metastatic Small Intestine Neuroendocrine Tumors and Survival: A Propensity Score-Matched Analysis

Background At present, it has been controversial whether primary tumor resection (PTR) can bring survival advantage to patients with metastatic small intestine neuroendocrine tumors (SI-NETs). To answer this question, we conducted a retrospective cohort study to evaluate the effect of PTR on the survival of patients with metastatic SI-NETs. Methods Information on SI-NETs patients from 2004 to 2015 was extracted from Surveillance, Epidemiology, and End Results (SEER) databases. Demographics, tumor characteristics, treatment, and survival were compared. Propensity score-matched (PSM) was used 1:1 in the filtered queue. Cox proportional hazard regression model was used to evaluate the correlation between PTR and treatment results. Results Before PSM, survival analysis showed that PTR significantly prolonged the survival of metastatic SI-NETs patients. After PSM, there was no significant difference in overall survival (OS) and cancer-specific survival (CSS) between the PTR group and the non-PTR group. Multivariate analysis showed no significant difference in OS and CSS between the two groups (p > 0.05). Conclusion Our study shows that OS and CSS are comparable between the PTR group and the non-PTR group. Thus, we believe that PTR should not be actively performed on such patients. Meanwhile, it is undeniable that properly selected patients may also benefit from PTR. Therefore, prospective randomized controlled trials are still needed to verify the effect of PTR on patients in the future.