Effect of opiates, anesthetic techniques, and other perioperative factors on surgical cancer patients.

BACKGROUND: Opioid pharmacotherapy is often used to treat cancer pain. However, morphine and other opioid-like substance use in patients with cancer may have significant adverse consequences, including the suppression of both innate and acquired immune responses. Although studies have examined the possibility that regional anesthesia attenuates the immunosuppressive response of surgery, the effects of morphine and other opioid-related substances on tumor progression remain unknown.

METHODS: This article presents an evidence-based review of the influence of opioids and anesthetic technique on the immune system in the context of cancer recurrence. The review focuses on the field of regional anesthesia and the setting of surgical oncologic procedures. The method for perioperative pain management and the technique of anesthesia chosen for patients in cancer surgery were explored.

RESULTS: General anesthetics have been indicated to suppress both cell-mediated immunity and humoral immunity. Evidence suggests that intravenous opioids suppress the immune system. However, the mechanisms by which anesthetics and analgesics inhibit the immune system are not understood. Compared with the alternatives, regional analgesia offers reduced blood loss and superior postoperative analgesia. Because of these advantages, the use of regional analgesia has increased in oncologic surgeries.

CONCLUSION: Immune responses from all components of the immune system, including both the humoral and cell-mediated components, appear to be suppressed by anesthetics and analgesics. The clinical anesthesiologist should consider these factors in the application of technique, especially in cancer surgery.