Anesthesia and cancer recurrences: The current knowledge and evidence

Surgical removal of solid tumors is of utmost importance as total resection can be curative. The surgical insult however itself may result in tumor micrometastasis coupled with depression of cell-mediated immunity culminating in tumor recurrence. Recent research suggests that few anesthetic agents or procedures can influence pathophysiology of metastasis in the postoperative period. Whereas opioids and volatile anesthetics have been implicated in angiogenesis and immunosuppression, evidences accumulated over the recent years have undoubtedly highlighted the attenuation of immunosuppression by regional anesthetic agents thereby making it superior over general anesthesia in preventing cancer recurrence. As anesthetic drugs are given at that time when patient is at the maximum risk of spread of metastasis, thus an understanding of the effect of anesthesia drugs and their impact on tumor metastasis is important so that appropriate anesthetic strategy can be made to improve long term survival in these patients. The purpose of the present review is therefore to emphasize the pivotal role of various anesthetic agents and anesthesia techniques in preventing tumor recurrence after surgery.