Can anesthetic techniques or drugs affect cancer recurrence in patients undergoing cancer surgery?

Despite the development of effective chemotherapy and radiotherapy, surgery remains the mainstay treatment of many cancers, requiring anesthesia. Almost all cancer deaths after primary surgery are attributable to recurrence or metastases. Recently it has been hypothesized that the perioperative anesthetic management of cancer patients could potentially affect the risk of recurrence and metastases, which implies a key role for anesthesiologists in choosing anesthetic agents and techniques that optimize the balance between the metastatic potential of the tumor versus its elimination by antimetastatic immune defenses. This review summarizes available experimental information on the potential effects of common anesthetic agents and techniques on cancer metastases and the conflicting retrospective clinical data on regional anesthesia in various types of cancer. A number of prospective, randomized, multicenter, clinical trials are in progress, and their results are eagerly awaited.