Breast cancer is often initiated by abnormal cellular mechanisms and damage to DNA brought about by different types of cellular stress. This book reviews the current standards of pathological assessment of breast cancer specimens. There is a discussion of recent molecular profiling studies in breast cancer and how our view of the classification of breast cancer is changing. The current role of molecular tests in the management of breast cancer is also addressed, highlighting their strengths and limitations. Additionally, it is widely acknowledged that the extracellular matrix (ECM) of connective tissues plays active roles in numerous biological processes such as cell differentiation, life/death promotion and carcinogenesis. The studies on embryo-foetal collagen type (OF/LB) and type V collagens are discussed and their putative relevance in ductal infiltrating carcinoma (DIC) ingrowth. This book also assesses the level and determinants of knowledge about, and risk factors for, breast cancer among women in the child bearing period. A review of the literatures regarding the injection sites of tracers in breast cancer sentinel lymph node (SLN) biopsy is examined as well.