Pathologic complete response and changes related to T-infiltrating lymphocytes and regulatory T cells in tissue and peripheral blood after neoadjuvant chemotherapy in breast carcinoma.

e22073 Background: Some clinical trials in breast cancer have reported imppressive outcomes related to laboratory immune findings in the neoadjuvant setting. In this context, tumor infiltrating lymphocytes (TILs) and regulatory T cells (Tregs) in tissue specimens and in peripheral blood are being tested as two emerging prognostic and predictive factors. We designed a protocol to analyze specifically TILs before, during and after neoadjuvant chemotherapy (CT) in breast cancer in blood and tissue, and their eventual relation with pathological complete response. Methods: From March 2011 to January 2013, 48 patients (18 HER2+/ 30 HER2-) with T2-4 N0-3 breast carcinoma treated with neoadjuvant chemotherapy in the Breast Cancer Unit of the Hospital Universitario Virgen Macarena (Seville, Spain) were included in the study protocol. CD3+, CD8+, CD8-16-56+ and Foxp3+ cell infiltrates were detected by immunohistochemistry before and after the end of neoadjuvant chemotherapy in tissue specimens. Blood samples were c...