The effect of peridural analgesia on long-term survival after surgery in patients with colorectal cancer : A systematic meta-analysis

Abstract

The results of recent clinical studies suggest a potential benefit of peridural analgesia (PDA) during general anesthesia on long-term survival in patients after surgery for colorectal cancer. In order to test the hypothesis a meta-analysis was performed. To determine the prognostic impact of perioperative PDA on long-term survival in patients with colorectal cancer who underwent surgical resection. By searching the relevant literature (up to May 2014) a total of 5 studies were identified from a total of 608 publications and a meta-analysis was carried out. Adjusted hazard ratios (HR) with 95 % confidence intervals (CI) were used to assess the strength of associations. The random effects model was used to analyze the data and a modified forest plot was applied. Additionally, a potential publication bias was visually examined in a funnel plot. A positive association between PDA and improved long-term survival was observed in patients who underwent surgery for colorectal cancer without metastases (HR = 0.81, 95 % CI 0.68-0.96, p = 0.055). Despite a publication bias the use of PDA in patients who underwent surgery for colorectal cancer without metastases seemed to be advantageous. Randomized controlled trials are warranted to confirm the positive effects of additional PDA. The exact mechanisms of tumor suppressive effects of PDA have not yet been elucidated.