Surgery is first-line treatment for solid tumors. However, surgical trauma-induced physiologic stress has been demonstrated to facilitate metastasis and recurrence in different types of cancer. It has been reported that the PD-1/PD-L1 pathway could be activated by surgical stress. Hence, we instigate the effect of anesthetic technique on expression of PD1 and PD1 ligand.

The cellular immune response plays a central part in postoperative clearance of tumor cells. T lymphocytes and natural killer (NK) cells are two predominant cytotoxic effector cells that are the major components of antitumor immunity. In mouse models, proliferation of T lymphocytes in response to surgical trauma is defective . Programmed death-1 (PD-1) belongs to the CD28 receptor superfamily. It is an inhibitory receptor, and its expression is upregulated on activated leukocytes, resulting in an inhibited immune response. PD-1 interacts with two ligands: programmed death ligand-1 (PD-L1, also referred to as B7-H1) and programmed death ligand-2 (PD-L2, also known as B7-DC). PD-L2 is expressed mainly on activated dendritic cells (DCs) and macrophages, whereas PD-L1 is distributed widely. In addition to immune cells, some subsets of tumor cells also express PD-L1 to escape from immunosurveillance. It has been reported that the PD-1/PD-L1 pathway could be activated by surgical stress. Hence, we instigate the effect of anesthetic technique on expression of PD1 and PD1 ligand.

Inclusion Criteria:

• patients scheduled for breast cancer surgery

Exclusion Criteria:

• compromised immune function (such as infection with the human immunodeficiency virus, immunodeficiency, or treatment with corticosteroids, immunosuppressive drugs, or chemotherapy)
• ASA > III
• age> 70 years old.
• patients refusal to the procedure.
• Infection of the skin at or near site of needle puncture.
• Coagulopathy .
• Drug hypersensitivity or allergy to the studied drugs.
• Central or peripheral neuropthy .
• Pre-operative opoid consumption ( within 24 hours preoperative )
• Anomalies of the vertebral column .