Effect of anaesthetic technique on oestrogen receptor-negative breast cancer cell function in vitro

Background. Metastatic recurrence is the main cause of breast cancer-related deaths. Tumour cell proliferation and migration are crucial steps in the metastatic process. Several perioperative factors, including general anaesthesia and opioid analgesia, adversely affect immune function, potentially increasing metastatic recurrence. Regional anaesthesia-analgesia has been consistently shown to attenuate the stress response to surgery, and also reduce opioid and general anaesthesia requirements, thereby attenuating this perioperative immunosuppression. We investigated the effect of serum from breast cancer surgery patients who received different anaesthetic techniques on breast cancer cell function in vitro. Methods. Patients were randomized to receive propofol/paravertebral anaesthesia-analgesia (propofol/paravertebral, n=11) or sevoflurane general anaesthesia with opioid analgesia (sevoflurane/opioid, n=11). The ER-negative MDA-MB-231 cell line was treated with patient serum from both groups. The effects on proliferation and migration were measured. Results. Treatment groups were well balanced for age, weight, surgical procedure, and cancer pathology. Pain scores were lower at I and 2 h in the propofol/paravertebral analgesia group. Compared with preoperative values, proliferation of MDA-MB-231 cells treated with postoperative patient serum at 10% concentration from the propofol/paravertebral group was significantly reduced compared with the sevoflurane/opioid group (-24% vs 73%, P=0.01). There was no significant change in MDA-MB-231 cell migration after treatment with patient serum between the two groups. Conclusions. Serum from patients receiving propofol/paravertebral anaesthesia for breast cancer surgery inhibited proliferation, but not migration, of ER-MDA-MB-231 cells in vitro, to a greater extent than that from patients receiving sevoflurane/opioid anaesthesia-analgesia. This implies that anaesthetic technique alters the serum molecular milieu in ways that may affect breast cancer cell function, possibly by altering anaesthetic and opioid drug administration and resultant pain scores.