Animal models have shown that
regional anesthesia (combined with or without
general anesthesia) would attenuate the surgical stress response by preserving immune function and result in better long-term outcome. In order to test the hypothesis that
cancer patients who had surgery with
epidural anesthesia (EA) would have better outcome (either overall survival [OS] or recurrence-free survival [RFS]) than those who were
general anesthesia (GA), we performed this meta-analysis. By searching relevant literature, a total of 14 studies containing 18 sub-studies (seven in OS analysis and eleven in RFS analysis) were identified and meta-analyzed. Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were used to assess the strength of association. For OS, the random-effects model was used to analyze the data and demonstrated an OS benefit in favor of EA compared with GA alone (HR = 0.84, 95% CI 0.74-0.96, P = 0.013). The influence analysis showed the robustness of the results. Specifically, a significantly positive association between EA and improved OS was observed in
colorectal cancer (HR = 0.65, 95% CI 0.43-0.99, P = 0.045). For RFS, the random-effects model was used to analyze the data and no significant relationship between RFS benefit and EA (HR = 0.88, 95% CI 0.64-1.22, P = 0.457) was detected. In conclusion, our meta-analysis suggests that
epidural anesthesia and/or
analgesia might be associated with improved overall survival in patients with operable
cancer undergoing surgery (especially in
colorectal cancer), but it does not support an association between
epidural anesthesia and
cancer control. Prospective studies are needed to determine whether the association between epidural use and survival is causative.