ABSTRACT
Mammaglobin-A (MAM-A) is a secretory protein that is overexpressed in 80 % of human breast cancers. Its near-universal expression in breast cancer as well as its exquisite tissue specificity makes it an attractive target for a breast cancer prevention vaccine, and we recently initiated a phase 1 clinical trial of a MAM-A DNA vaccine. Previously, we have identified multiple MAM-A CD8 T cell epitopes using a reverse immunology candidate epitope approach based on predicted binding, but to date no attempt has been made to identify epitopes using an unbiased approach. In this study, we used human T cells primed in vitro with autologous dendritic cells expressing MAM-A to systematically identify MAM-A CD8 T cell epitopes. Using this unbiased approach, we identified three novel HLA-A2-restricted MAM-A epitopes. CD8 T cells specific for these epitopes are able to recognize and lyse human breast cancer cells in a MAM-A-specific, HLA-A2-dependent fashion. HLA-A2(+)/MAM-A(+) breast cancer patients have an increased prevalence of CD8 T cells specific for these novel MAM-A epitopes, and vaccination with a MAM-A DNA vaccine significantly increases the number of these CD8 T cells. The identification and translational validation of novel MAM-A epitopes has important implications for the ongoing clinical development of vaccine strategies targeting MAM-A. The novel MAM-A epitopes represent attractive targets for epitope-based vaccination strategies, and can also be used to monitor immune responses. Taken together these studies provide additional support for MAM-A as an important therapeutic target for the prevention and treatment of breast cancer.
Subject(s)
Breast Neoplasms/therapy , CD8-Positive T-Lymphocytes/immunology , Cancer Vaccines/immunology , Cancer Vaccines/therapeutic use , Epitopes, T-Lymphocyte/immunology , Mammaglobin A/metabolism , Amino Acid Sequence , Breast Neoplasms/immunology , CD8-Positive T-Lymphocytes/metabolism , Female , HLA-A2 Antigen/metabolism , Humans , Mammaglobin A/genetics , Mammaglobin A/immunology , Molecular Sequence Data , Reproducibility of Results , Vaccines, DNA/immunology , Vaccines, DNA/therapeutic useABSTRACT
INTRODUCTION: Ccombination chemotherapy and radiation therapy is used for adjuvant treatment of stage III-IV endometrial cancer. The goal of this study was to review the treatment duration, toxicity, and survival for patients treated with concomitant chemotherapy and radiation. METHODS: Women with stage III-IV endometrial cancer treated with concurrent chemotherapy and radiation between 2006 and 2013 were included. Toxicities were classified per CTCAE v3.0 and RTOG/EORTC late radiation morbidity scoring. Descriptive statistics were used to quantify treatment and toxicities. Kaplan-Meier method was used to estimate survival. RESULTS: Fifty-one patients met our inclusion criteria. Median age was 60 (range 33-85). Thirty-six patients (70.6%) had endometrioid histology, 13 patients (25.5%) had serous, clear cell, or mixed histology, and 2 women (3.9%) had carcinosarcoma. Forty-eight patients had stage III disease and three patients were stage IVB. Mean treatment duration was 107 ± 19 days. Forty-two patients received all planned chemotherapy, and 16 patients required a dose reduction. Thirty-four patients (66.7%) experienced grade 3-4 toxicities, the majority of which were hematologic. There were no deaths related to therapy. Eighty-six percent of patients received leukocyte growth factors, and 25% of patients received a blood transfusion. Seven late grade 3-4 complications occurred: four gastrointestinal and two genitourinary, and one patient had ongoing neuropathy. Median progression-free survival was 42.8 months (range 4.4-81.5 months) and median overall survival was 44.9 months (range 5.1-82.6 months). Three-year overall survival was 80%. CONCLUSION: Concomitant chemotherapy and radiation is an adequately tolerated treatment modality that allows for shorter treatment duration.