Abstract LB-314: Patients with inflammatory breast cancer have significant reductions in immune cells responsible for adaptive immunity

Abstract

Abstract Background: Cell-mediated immunity is essential for maintaining immune surveillance against tumor progression. Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer, yet there is a paucity of information on peripheral blood leukocyte immunophenotypes of these patients. Therefore, we enumerated the immune cells of IBC patients with or without metastasis. Methods: This ongoing prospective study consists of 43 IBC patients, 22 with non-metastatic IBC and 21 with metastatic disease (MIBC). Peripheral blood was collected prior to starting a new therapy and analyzed to determine the immunophenotype of T cells, B cells, regulatory T (TR) cells, natural killer cells (NK), and dendritic cells (DC) by 6-color flow cytometry. The Kruskal-Wallis and Mann-Whitney U tests were used to determine the differences between healthy donors (HD, N=15), non-metastatic IBC and MIBC patients. Results: Among the 43 IBC patients, 22 are hormonal receptor (HR)+ with 11 HER-2+, 8 are HR- but HER2+, and 13 are triple receptor negative. Non-metastatic IBC patients have significantly lower median percentages (%) of lymphocytes (P=0.018), B cells (P=0.028), and myeloid DC (P=0.049), and higher median % TR cells (P=0.039) when compared with those of HD. In addition, non-metastatic IBC patients have significantly lower median counts of B cells (P=0.003), myeloid DC (P=0.009), and plasmacytoid DC (P=0.037) when compared with those of HD. Moreover, compared with non-metastatic IBC patients, MIBC patients were significantly older (P=0.029) and have significantly lower median % and absolute counts of lymphocyte and B cells (all P<0.02), lower median ratio of CD4+/CD8+ T cells (P=0.028), and lower median number of TR cells (P=0.013). Conclusion: This preliminary cross-sectional analysis suggests that non-metastatic IBC patients have significant reductions in various effector cells, in particular, B-cells and antigen-presenting DC that may lead to compromised adaptive immunity. Moreover, metastatic IBC patients are more immunocompromised than non-metastatic IBC patients. Longitudinal study is warranted to further assess the role of humoral and cell-mediated immunity in the pathogenesis of IBC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-314.