Cancer Research | 2019
Abstract P3-07-04: Molecular characterization of mucinous breast cancers
Abstract
Introduction Mucinous carcinoma, a special histological subtype of breast cancer (BC) which accounts for ˜2% of all invasive breast tumors, is characterized by the presence of extracellular mucin, typically expresses the estrogen receptor (ER), and lacks HER2 amplification. The majority of patients with mucinous BC are older at diagnosis, rarely present axillary lymph node metastases, and are associated with a better prognosis as compared to invasive ductal cancer patients (IDC, formally referred to as “breast cancer of no special type”). So far, it is unknown what is driving the mucinous phenotype of these tumors. Here we interrogated the genomics, transcriptomics, immune infiltration and epigenetics profiles of these tumors, using a retrospective institutional series and a publicly available dataset. Patients and methods After central pathology review and DNA extraction, a total of 31 pure mucinous cases from Institut J. Bordet Biobank were included (referred to as IJB cohort). Tumor infiltrating lymphocytes (TILs) were assessed on hematoxylin and eosin (HE 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-07-04.