Genomic and Proteomic Pathway Mapping Reveals Signatures of Mesenchymal-Epithelial Plasticity in Inflammatory Breast Cancer

1.1 Inflammatory breast cancer as a distinct clinicopathologic entity There are several clinically distinct types of breast cancer, which include early stage breast cancer, locally advanced breast cancer (LABC) and metastatic breast cancer. The most rare but lethal form of LABC is inflammatory breast cancer (IBC) (reviewed in 1). This type of breast cancer accounts for an estimated 25% of all breast cancers in the United States and up to 20% of all breast cancers globally (2-4). Although primary IBC is less commonly diagnosed than other types of breast cancer, IBC is responsible for a disproportionate number of breast cancer-related deaths that occur each year world-wide due to its propensity to rapidly metastasize. (2-4). Women diagnosed with IBC have a significantly shorter median survival time (~ 2.9 years) than women with either LABC (~ 6.4 years) or non-LABC breast cancer (>10 years). The clinical diagnosis of IBC is based on the combination of the physical appearance of the affected breast, a careful medical history, physical examination, and pathological findings from a skin biopsy and/or needle or core