A systematic review and meta-analysis of the efficacy and safety of long-acting release somatostatin analogs in patients with advanced neuroendocrine neoplasms

Background: Because the morbidity of neuroendocrine neoplasms (NENs) increases each year, clinical trials are increasingly exploring treatment options to control tumor growth. These trials have revealed that long-acting release (LAR) somatostatin analogs (SSAs) are effective therapies. The objective for this article is to perform a meta-analysis to assess the efficiency and safety of SSAs in delaying NEN progress. Methods: To identify clinical trials of SSAs in NENs published until May 2016, we searched PubMed, the Cochrane Library and the CBM databases by combining various key words. Both retrospective and prospective studies were included. Data were extracted from every study to perform a meta-analysis using RevMan 5.3 software. Results: Seven studies consisting of two randomized control trial (RCTs), one non-RCT and four single-arm studies with a total of 788 patients were included. The pooled hazard ratio (HR) for progression-free survival/time to progression (PFS/TTP) was 0.43 (95% CI: 0.36-0.51, P<0.00001) for all included studies. The pooled HR of the two RCTs was similar (HR = 0.41 95% CI: 0.29-0.58, P<0.00001). However, SSAs did not improve the tumor objective response rate (ORR) with a pooled risk ratio (RR) of 0.88 (95% CI: 0.38-2.02, P=0.68), and SSAs did not increase the adverse events (AEs), including diarrhea, abdominal pain and hyperglycemia. Conclusions: SSAs LAR are beneficial for advanced NENs and can significantly delay tumor progression. Moreover, these drugs are safe and do not increase the rate of AEs.