Major abdominal surgery for cancer: Does epidural analgesia have a long-term effect on recurrence-free and overall survival?

Background: Retrospective studies have suggested that regional analgesia combined with general anaesthesia could decrease cancer recurrence. The purpose of this study was to assess the influence of regional analgesia on recurrence-free (RFS) and overall survival in patients undergoing major intra-abdominal surgery for cancer. Method: Patients previously included in a prospective randomized study comparing two postoperative techniques of analgesia were retrospectively studied. The EP group received general anaesthesia with bupivacaine thoracic epidural analgesia and the SC group received general anaesthesia with fentanyl followed by continuous subcutaneous morphine. Results: One hundred and thirty-two patients were analyzed (63 and 69 in SC and EP group, respectively) with a 17-year-median follow-up. After 5. years, RFS was 43% [95% CI: 32%-55%] in EP group and 24% [95% CI: 15%-36%] in SC group, but the difference did not reach statistical significance for RFS nor for overall survival (P=0.10 and 0.16 respectively). Using multivariable analysis over the whole follow-up period, the type of analgesia was not a statistically significant predictive factor for RFS (EP/SC, HR. =1.3 [95% CI: 0.8-2.0%]). The anaesthesia effect changed moderately over the follow-up and HR for overall survival (EP/SC) reached statistical significance after 5, 6 and 8. years. Conclusion: Despite a trend in favour of the epidural, this retrospective review of patients included in a previous randomized study failed to demonstrate a statistically significant association between the perioperative analgesia and RFS after abdominal surgery for cancer. The duration of follow-up may have an impact on the analgesia effect on survival.