Impact of Fentanyl and Remifentanil on Immune Response in Breast Cancer Patients Post-surgery

The perioperative period may influence immune function in cancer patients, with anesthetic agents potentially contributing to immunosuppression. This study evaluated the differential impact of fentanyl and remifentanil on immune cell populations in breast cancer (BCa) patients undergoing surgery.

Thirty patients with histologically confirmed BCa who were treated with modified radical mastectomy or breast-conserving surgery followed by radiotherapy were included in the study. Anesthesia was administered using either fentanyl (n=12) or remifentanil (n=18). White blood cell (WBC) and lymphocyte (LC) counts were recorded before and 24 h after surgery. Peripheral blood mononuclear cells were analyzed for T-cell subpopulations using flow cytometry.

WBC counts increased from a median of 7,025/μl before to 10,065/μl after surgery (p<0.0001), whilst LC counts were reduced from a median value of 1,785 to 1,090 (p=0.0002). The median duration of anesthesia was 212 min. Patients who received remifentanil for a shorter anesthesia period (<212 min) experienced a marginal non-significant degree of leukocytosis (p=0.07), while no lymphopenia was evident (p=0.38). In contrast, longer remifentanil exposure significantly induced significant leukocytosis (p=0.01) and lymphopenia (p=0.009), similar to fentanyl. There were no significant differences between fentanyl and remifentanil in their effects on CD4+, CD8+, or CD4+/CD25+/FOXP3+ T-cell populations. Notably, the percentage of CD4+ T-cells was positively correlated with the duration of anesthesia (p=0.002, r=0.53).

Optimizing analgesic selection and anesthesia duration may play a crucial role in minimizing immunosuppressive perioperative stress in patients undergoing BCa surgery. Remifentanil combined with shorter anesthesia exposure appears to mitigate immune suppression, suggesting a potential strategy to preserve immune competence during oncologic surgery.