Cervical epidural anesthesia is associated with increased cancer-free survival in laryngeal and hypopharyngeal cancer surgery: a retrospective propensity-matched analysis.

BACKGROUND AND OBJECTIVES: Regional anesthesia preserves perioperative immune competence and may reduce the risk of recurrence and metastasis after cancer surgery. Cervical epidural anesthesia provides adequate analgesia for head and neck cancer surgery, but its impact on cancer recurrence is unknown.
METHODS: This study was a single-center retrospective cohort study of patients undergoing larynx or hypopharynx cancer surgery between January 1984 and December 2008. One hundred eleven patients had general anesthesia combined with intraoperative and postoperative cervical epidural; 160 had general anesthesia alone with postoperative morphine. From this cohort, matched pairs were selected using a propensity score to balance potential confounders of receiving epidural anesthesia. The primary end point was the length of cancer-free survival after surgery until September 2009.
RESULTS: Propensity-based matching produced 65 pairs. Matching was effective in achieving balance between groups for each of the preoperative variables collected. Combined epidural and general anesthesia (68% 5-year cancer-free survival; 95% confidence interval [CI], 57%-82%) was associated with significantly increased cancer-free survival compared with general anesthesia alone (37% 5-year cancer-free survival; 95% CI, 25%-54%) with a corresponding adjusted hazard ratio of 0.49 (95% CI, 0.25-0.96; P = 0.04). Patients in the epidural group had an increased overall survival compared with the non-epidural group (P = 0.03).
CONCLUSIONS: The association between cervical epidural anesthesia and increased cancer-free survival found in this retrospective study should be an important hypothesis to further investigate in head and neck cancer surgery.