Pathogenesis of Breast Cancer

Abstract

A hallmark of cancer is tumour heterogeneity. This is generally attributed to genomic instability and phenotypic drifting of transformed cells. In recent years another source of tumour heterogeneity has emerged--the "cancer initiating cells" or "cancer stem cells". These are very rare cancer cells that are believed to fuel the bulk of the epithelial cells composing the tumour. Here we discuss the possible existence of normal and cancer stem cells in the human breast and in breast cancer and their potential role in the evolution of this disease.