THE EFFECT OF REGIONAL VS. GENERAL ANESTHESIA ON THE IMMUNE RESPONSE IN BREAST CANCER SURGERY: A NARRATIVE REVIEW OF THE LITERATURE.

For breast cancer patients, surgery remains the cornerstone in treatment. Perioperative and postoperative period is associated with impaired immune function that can have profound implications for cancer patients in terms of tumor recurrence and metastases. The three main factors include surgery and related neuroendocrine stress response, anesthetic drugs, including opioid analgesics and postoperative pain. The most investigated immune cells are natural killer (NK) cells that are affected by both anesthesia and surgery. It has been demonstrated that ketamine, thiopental, volatile anesthetics, fentanyl and morphine, but not propofol, remifentanil or tramadol reduce the number of circulating NK cells and depress their toxicity. The level of NK cells' cytotoxicity is inversely proportional to the stage and spread of cancer. Regional anesthesia and its potential beneficial effects on the perioperative immune response and long-term outcome after surgery has been investigated as an alternative to general anesthesia in patients undergoing breast cancer surgery. In this paper, we present a review of literature aimed to assess the impact of regional anesthesia techniques on the immune response in patients undergoing breast cancer surgery and how it compares to general anesthesia.