Can Anesthetic Technique for Primary Breast Cancer Surgery Affect Recurrence or Metastasis?
Aristomenis K. Exadaktylos,* Donal J. Buggy,* Denis C. Moriarty,* Edward Mascha,† Daniel I. Sessler,‡
(Anesthesiology, 105:660-664, 2006)
*University Department of Anaesthesia and Intensive Care Medicine, Mater Misericordiae University Hospital and National Breast Screening Programme (Eccles Unit), Dublin, Ireland; †Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio; and ‡Outcomes Research Institute, Louisville, KY.
Chemotherapy and endocrine and radiation therapy are all part of the treatment for breast cancer; surgical removal of the tumor offers the best prospect for a good prognosis. Surgery induces a profound neuroendocrine, metabolic, and cytokine response that can lead to transient perioperative inhibition of immune function. Regional anesthesia prevents this surgical stress response and might attenuate perioperative factors that enhance tumor growth and spread. Use of paravertebral anesthesia and analgesia combined with general anesthesia might lead to a lower incidence of cancer recurrence or metastases than surgery with general anesthesia and patient-controlled morphine analgesia in these patients. This retrospective analysis compared local recurrence and metastases in 129 patients who had breast cancer surgery with and without paravertebral analgesia.
Paravertebral anesthesia in combination with general anesthesia was offered to women undergoing extensive breast surgery involving axillary node clearance. A catheter was inserted before anesthesia induction into the ipsilateral paravertebral space at T2 or T3 using a standard technique (paravertebral group). General anesthesia was induced with fentanyl and propofol; morphine boluses were given to patients in either group intraoperatively. Those who did not receive paravertebral anesthesia received balanced general anesthesia with postoperative patient-controlled morphine analgesia. The main outcome was the incidence of metastatic spread or cancer recurrence after a follow-up interval of 2.5 to 4.0 years.
Fifty patients had surgery with paravertebral and general anesthesia, and 79 had general anesthesia with postoperative morphine analgesia. The patient groups did not differ in demographic characteristics; the median pain score was less in the paravertebral group than in the general anesthesia group (1 and 3 and 1 and 2 at 4 and 24 hours, respectively). Two patients in the paravertebral group required morphine. Two paravertebral and 3 general anesthesia patients developed infections. Tumor presentation and prognostic factors were similar in the 2 groups, with both groups having a mean Nottingham prognostic index score in the intermediate range. The paravertebral and anesthesia groups were similar in chemotherapy, radiation therapy, chemotherapy + radiation therapy, and endocrine therapy received (24 and 43, 36 and 60, 22 and 39, and 27 and 44 patients, respectively). Three patients (6%) in the paravertebral group and 19 patients (24%) in the general anesthesia group had documented recurrence or metastasis during the follow-up period; 94% of the paravertebral patients and 82% of the general anesthesia patients were recurrence-free at 24 months, and 94% and 77%, respectively, were recurrence-free at 36 months. Adjusting for histological grade and axillary node involvement, recurrence was significantly less in the paravertebral group. Only 1 patient, in the general anesthesia group, died during follow-up; she had lung and bony metastases.
There was a substantial reduction in tumor recurrence and metastases when breast cancer surgery was performed with paravertebral anesthesia and analgesia. Cancer surgery releases tumor cells into the surrounding healthy tissue and the systemic circulation. Whether these cells become recurrent cancer or metastases depends, perhaps, on immune competence in the immediate perioperative period. Regional analgesia and anesthesia may preserve immune function, but prospective trials are necessary to confirm this hypothesis.