Quantitative assessment of CD3, CD8, and CD20 in tumor-infiltrating lymphocytes and predictive value for response to neoadjuvant chemotherapy in breast cancer.

Abstract

1027 Background: Tumor infiltrating lymphocytes (TILs) have been associated with response to neoadjuvant therapy. However, typical analysis of TILs is subjective, semi-quantitative and does not differentiate between subpopulations. Here we describe a quantitative objective method for measurement of TIL subsets, including CD3, 8, and 20 and assess their predictive value for therapeutic response. Methods: We used a quantitative immunofluorescence (QIF) assay to measure stromal expression of CD3 (T cell), CD8 (cytotoxic T cell), and CD20 (B cell) on a single slide using AQUA technology. This method was validated by comparison to flow cytometry on fresh tonsil tissue. To assess the predictive value of TIL markers, we used a cohort of 105 consecutive (2002 - 2010) invasive breast cancer patients that received neoadjuvant therapy and had obtainable pre-surgical biopsy tissue. Percentage TIL infiltrate in the tumor stroma was estimated by two pathologists on H and E stained slides of these biopsies. Images from ...