Women diagnosed with breast cancer undergoing elective surgery under general anesthesia will be randomly allocated to dexmedetomidine group or control group. Patients from both groups will receive midazolam, propofol, fentanyl, remifentanil and CIS atracurium for total intravenous anesthesia. BIS value will be controlled between 40-60 during surgery. Patients of dexmedetomidine group will receive a loading does of 1ug/kg dexmedetomidine since 15 mins before induction, and receive another 1ug/kg of dexmedetomidine at a rate of 0.5ug/kg/h for 2 continuous hours during surgery. Patients of control group will receive same amount of normal saline. Serum will be collected from patients of both groups at before induction and 1h post-surgery. The MCF-7 breast cancer cell line will be treated with patient serum from both groups. The effects of dexmedetomidine on cellular proliferation, migration and metastasis will be measured.
