Breast cancer surgery-induced immunomodulation.

Background And Objectives: Surgical procedures can cause tumor cells to disseminate into the circulatory system. Although this spread of metastatic cells will be limited by immune activity, immunosuppression tends to be the main effect resulting from surgery. The objective of this study is to assess hormonal and immunological changes induced by breast cancer surgery.

Methods: Endocrine and immune responses to surgery were determined in 27 breast cancer patients. Blood samples were taken at 6 days and 1 day before surgery and 2 hr, 1 day, and 5 days after surgery. Changes in endocrine function, number of leucocytes and their subpopulations, enumerative immune expression, functional activity, and cytokine levels were determined.

Results: Breast cancer surgery induces a pro-inflammatory response and leucocytosis. Immunosuppression is indicated by decreased HLA-DR expression, decreased NKCA, and a Th2 response. A delayed Th1 response was also found 5 days after surgery. As no cortisol level change was observed, this hormone can be excluded as the mediator of surgery-related immunomodulation in breast cancer.

Conclusion: Although breast cancer surgery is classified as minor surgery the surgical procedure produces substantial immunomodulation.