Autologous dendritic cell vaccine for estrogen receptor (ER)/progestin receptor (PR) double-negative breast cancer

A wealth of preclinical information, as well as a modest amount of clinical information, indicates that dendritic cell vaccines have therapeutic potential. The aim of this work was to assess the immune response, disease progression, and post-treatment survival of ER/PR double-negative stage II/IIIA breast cancer patients vaccinated with autologous dendritic cells pulsed with autologous tumor lysates. Dendritic cell (DC) vaccines were generated from CD14+ precursors pulsed with autologous tumor lysates. DCs were matured with defined factors that induced surface marker and cytokine production. Individuals were immunized intradermally four times. Specific delayed type IV hypersensitivity (DTH) reaction, ex vivo cytokine production, and lymphocyte subsets were determined for the evaluation of the therapeutic efficiency. Overall survival and disease progression rates were analyzed using Kaplan-Meier curves and compared with those of contemporaneous patients who were not administered DC vaccines. There were no unanticipated or serious adverse effects. DC vaccines elicited Th1 cytokine secretion and increased NK cells, CD8+ IFN-gamma+ cells but decreased the percentage of CD3+ T cells and CD3+ HLA-DR+ T cells in the peripheral blood. Approximately 58% (18/31) of patients had a DTH-positive reaction. There was no difference in overall survival between the patients with and without DC vaccine. The 3-year progression-free survival was significantly prolonged: 76.9% versus 31.0% (with vs. without DC vaccine, p < 0.05). Our findings strongly suggest that tumor lysate-pulsed DCs provide a standardized and widely applicable source of breast cancer antigens that are very effective in evoking anti-breast cancer immune responses.