Year: 2023
Type: preprint
Abstract: Breast cancer is heterogeneous and differs substantially across different tumors (intertumor heterogeneity) and even within an individual tumor (intratumor heterogeneity).Gene-expression profiling has considerably impacted our understanding of breast cancer biology.Four main "intrinsic subtypes" of breast cancer (i.e., luminal A, luminal B, HER2-enriched, and basal-like) have been consistently identified by gene expression, showing significant prognostic and predictive value in multiple clinical scenarios.Thanks to the molecular profiling of breast tumors, breast cancer is a paradigm of treatment personalization.Several standardized prognostic gene-expression assays are presently being used in the clinic to guide treatment decisions.Moreover, the development of single-cell-level resolution molecular profiling has allowed us to appreciate that breast cancer is also heterogeneous within a single tumor.There is an evident functional heterogeneity within the neoplastic and tumor microenvironment cells.Finally, emerging insights from these studies suggest a substantial cellular organization of neoplastic and tumor microenvironment cells, thus defining breast cancer ecosystems and highlighting the importance of spatial localizations.B reast cancer has long been recognized as a heterogeneous disease.For many decades and to this day, breast cancers have been pathologically diagnosed as estrogen receptor (ER)-positive/-negative, human epidermal receptor 2 (HER2)-positive/-negative, and progesterone receptor (PR)-positive/-negative.These three therapeutic biomarkers then, in essence, define three clinical groups that are ER/PR + /HER2 -, HER2 + , and triple-negative breast cancer (TNBC) (i.e., negative for ER, PR, and HER2).This classification provides not only prognostic information but also treatment directions, which is the main driving reason for ER, PR, and HER2 testing.With the development of DNA microarray technology for profiling transcriptomes, breast cancers have been additionally classified into four main genomic "intrinsic" subtypes: luminal A, luminal B,
Language: English
Subfield: Cancer Research
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W4417147352