Retrospective analysis of the effect of postoperative analgesia on survival in patients after laparoscopic resection of colorectal cancer

Surgical excision of colorectal cancer can reduce immune function during the postoperative period, which may affect long-term survival. There is evidence that regional analgesia may attenuate the immunosuppressive effect of surgery. Opioid analgesia also suppresses cell-mediated immunity, notably natural killer cell activity. Therefore, using either epidural or spinal analgesia rather than systemic opioids during the postoperative period could affect long-term survival and disease recurrence. A retrospective analysis of a prospective database of all patients undergoing laparoscopic colorectal resection for adenocarcinoma between October 2003 and December 2010 was performed. Patients received either an epidural, spinal block, or a morphine patient-controlled analgesia (PCA) for their primary postoperative analgesia. Overall survival and disease-free survival were analysed. A total of 457 laparoscopic colorectal resections were performed during the period analysed; 424 cases were suitable for analysis (epidural=107, spinal=144, and PCA=173). There was no significant difference between the groups for age, gender, conversion rate, operation performed, TNM stage, tumour differentiation, extramural venous, or lymphovascular invasion. The epidural group had significantly more ASA category III patients (P=0.006). The median length of stay was significantly longer in the epidural group at 5 days compared with 3 days for spinal and PCA (P