Does anesthetic technique or the use of postoperative analgesia affect cancer recurrence and patient survival? Studies in humans have been mixed. In two studies of breast and cancer surgery, metastatic burden was reduced with regional anesthesia. Conversely, in three others, regional anesthesia showed no advantage.
Dr. Weian Zeng, Anesthesiology Department, State Key Laboratory in South China, Sun Yat-Sen University Cancer Center, Guangzhou, P.R. China, and coauthors undertook a retrospective review of 819 patients with hepatocellular carcinoma (HCC) who underwent hepatic resection at the Cancer Center of Sun Yat-Sen University from January 1997 to December 2007. The results of their analysis are published in this month’s issue of Anesthesia and Analgesia in the article titled “Long-term Survival After Resection of Hepatocellular Carcinoma: A Potential Risk Associated with the Choice of Postoperative Analgesia.”
All patients had the same balanced anesthetic. Those with epidural catheters had them inserted in the low thoracic region (T9-T10 or T10-T11) before the induction of anesthesia. The epidural was not used until after the procedure but was continued for 48 hours after surgery to deliver epidural morphine. Patients who did not receive epidural analgesia received intravenous fentanyl to manage postoperative pain. Patient follow-up was for slightly over 4 years.
Preoperative liver function was worse in patients who received epidural anesthesia. Cancer recurrence was greater in patients who received epidural anesthesia (38%) compared to those who received postoperative fentanyl (31%). Mortality was 41% for patients in the epidural anesthesia group vs. 30% for those in the postoperative fentanyl group. Postoperative epidural anesthesia with morphine was an independent risk factor for decreased long-term survival in patients after HCC resection.
This is another retrospective review of the effects of regional vs. IV opiate analgesia on cancer recurrence, but with a couple of twists: (1) a different tumor type, and (2) the negative effects of epidural anesthesia. Also, the authors clearly state that the epidural was NOT used intraoperatively (here it was in order to decrease the risk of awareness during anesthesia), which is unknown in many of the other trials.
It seems likely that the epidural anesthesia was likely chosen for patients with more extensive tumors. If so, poorer survival was seen in patients with epidural anesthesia because epidural anesthesia is a marker for advanced disease. However, the authors attempted to control for this in their analysis.
The causative link, if any, of epidural anesthesia to survival can only be resolved with double blind randomized studies of adequate power to see if epidural anesthesia has a survival advantage or (in this case) disadvantage in patients with cancer.