Somatostatin analogues compared to placebo and other pharmacological agents in the management of symptoms of inoperable malignant bowel obstruction: a systematic review

Abstract Context Somatostatin analogues are commonly used to relieve symptoms in malignant bowel obstruction (MBO) but are more expensive than other anti-secretory agents. Objective To evaluate the evidence of effectiveness of somatostatin analogues compared to placebo and/or other pharmacological agents in relieving vomiting in patients with inoperable MBO. Method MEDLINE, EMBASE, CINAHL, The Cochrane Controlled Trials Register databases were systematically searched; reference lists of relevant articles were hand-searched. Cochrane risk of bias tool was used. Results The search identified 420 unique studies. Seven randomised controlled trials (RCTs) met the inclusion criteria (six octreotide studies; one lanreotide); 220 people administered somatostatin analogues and 207 placebo or hyoscine butylbromide. Three RCTs compared a somatostatin analogue with placebo and four with hyoscine butylbromide. Two adequately powered multicentre RCTs with a low Cochrane risk of bias reported no significant difference between somatostatin analogues and placebo in their primary endpoints. Four RCTs with a high/unclear Cochrane risk of bias reported that somatostatin analogues were more effective than hyoscine butylbromide in reducing vomiting. Conclusion There is low-level evidence of benefit with somatostatin analogues in the symptomatic treatment of MBO. However, high level evidence from trials with low risk of bias found no benefit of somatostatin analogues for their primary outcome. There is debate regarding the clinically relevant study endpoint for symptom control in MBO and when it should be measured. The role of somatostatin analogues in this clinical situation requires further adequately powered, well designed trials with agreed clinically important endpoints and measures.