Introduction: The role of surgery to resect the primary lesion in incurable metastatic small intestinal (SI-NET) and pancreatic neuroendocrine tumours (P-NET) remains controversial. Recent evidence suggests that palliative surgery may increase survival even in asymptomatic patients with non-functioning tumours. The present study investigated the value of palliative resection of the primary tumour in SI-NET and P-NET by systematic literature review and meta-analysis.
Methods: 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: About 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: 0.340.57, P<0.001) and SI-NETs (HR 0.47; 95% CI: 0.350.55, P=0.007). No significant heterogeneity was detected across the studies (I2=0%, P=0.625). Additional survival in patients treated surgically relative to non-surgically ranged from 14 to 46 months in P-NET, and 22 to 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 primary SI-NET and P-NET resection in incurable 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 palliative surgery, particularly in patients with low tumour burdens and good functional status.