Role of Esophageal Metal Stents Placement and Combination Therapy in Inoperable Esophageal Carcinoma: A Systematic Review and Meta-analysis

Introduction: More than 50% of patients with esophageal cancer already have inoperable disease at the time of diagnosis. Controversy surrounds the outcomes of patients with advanced esophageal cancer who receive palliative care by either stent alone or stent plus an additional modality. We set out to perform a systematic review and meta-analysis of studies assessing the use of metal stents as treatment options for symptomatic improvement, survival, and adverse events. Methods: We searched Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception until January 14, 2016, as well as other databases for randomized controlled trials (RCTs) comparing esophageal stent versus either esophageal stent plus brachytherapy, radiotherapy, or chemotherapy. For quality assurance purposes throughout the systematic review, multiple independent extractions were performed, and the process was executed as per the standards of the Cochrane collaboration. Primary outcomes were mean change in dysphagia score, overall survival, and quality of life. Secondary outcomes were adverse events including fever, severe pain, aspiration, fistula, stent migration, perforation, and restenosis. Results: Eight RCTs enrolling 732 patients were included with three distinct comparisons: stents combination therapy vs stents alone (5 studies, n = 417), stents alone versus brachytherapy alone (2 studies, n = 274), and stents + brachytherapy vs brachytherapy alone (1 study, n = 41). Stents combination therapy was defined as stents plus radiotherapy, chemotherapy, or both. Mean change in dysphagia scores favored stents combination therapy versus stents alone, and the effect was seen in patients surviving longer than 3 months. Stents combination therapy was also associated with a more favorable overall survival. The risks of stent migration, aspiration pneumonia, and restenosis were lower in the stents combination group compared to stents alone, while the risks of severe pain, hemorrhage, and fistula formation were higher. Changes in dysphagia scores and overall survival did not differ significantly in the brachytherapy-alone vs stents-alone comparison. The risk of fistula formation and hemorrhage were higher in the stents-alone group, while the risk of perforation was lower, compared to brachytherapy alone. Quality of life improvements were seen in all treatment groups, but were not pooled in analysis due to differing methods of measurement. Discussion: While there appears to be no immediate short-term differences, those who live longer than 3 months experience a significant improvement in dysphagia score using a stents combination therapy approach vs stents alone. The combination therapy significantly improves the overall survival as well as showed improvements in quality of life scores. Larger randomized controlled trials are needed to assess improvements in dysphagia score, overall survival, quality of life, and adverse events.