Role of palliative resection of the primary tumour in advanced pancreatic and small intestinal neuroendocrine tumours: A systematic review and meta-analysis

Purpose This study aimed to evaluate the impact on overall survival following palliative surgery to remove the primary lesion in unresectable metastatic small intestinal (SI-NET) and pancreatic neuroendocrine tumours (P-NET). Methods A systematic review of the literature and meta-analysis was performed. MEDLINE and Embase databases were searched to identify articles comparing patients undergoing palliative primary tumour resection without metastatectomy vs. no resection. Relevant articles were identified in accordance with PRISMA guidelines. The primary outcome was overall survival. Included studies were evaluated for heterogeneity and publication bias. Results 13 studies met the inclusion criteria, of which 6 presented data suitable for meta-analysis. No randomised controlled trials were identified. Analysis of pooled multivariate hazard ratios demonstrated significantly longer overall survival in patients undergoing resection of both P-NETs (HR 0.43; 95% CI: 0.34–0.57, p < 0.001) and SI-NETs (HR 0.47; 95% CI: 0.35–0.55, p = 0.007). The increase in median survival in patients treated surgically relative to non-surgically ranged from 14 to 46 months in P-NET, and 22–112 months in SI-NET. The number needed to treat in order that one additional patient was alive at five years, ranged from 3.0 to 4.2, and 1.7 to 7.7 respectively. Conclusions Meta-analysis demonstrates that palliative resection of primary SI-NETs and P-NETs in the setting of unresectable metastatic disease can increase survival. Although these results should be interpreted with caution due to potential selection and publication bias, the data supports consideration of surgery, particularly in patients with low tumour burdens and good functional status.