What is ImmunoHistoChemistry breast cancer?
IHC, or ImmunoHistoChemistry, is a special staining process performed on fresh or frozen breast cancer tissue removed during biopsy. IHC is used to show whether or not the cancer cells have HER2 receptors and/or hormone receptors on their surface. This information plays a critical role in treatment planning.
What is basal type breast cancer?
Basal-like breast cancer (BLBC) is a particularly aggressive molecular subtype defined by a robust cluster of genes expressed by epithelial cells in the basal or outer layer of the adult mammary gland. BLBC is a major clinical challenge because these tumors are prevalent in young woman, often relapsing rapidly.
What are some characteristics of basal-like breast cancer in humans?
Histologically, the majority of basal-like breast cancers is of IDC-NST type, high histological grade, and characterized by exceptionally high mitotic indices, the presence of central necrotic or fibrotic zones, pushing borders, conspicuous lymphocytic infiltrate, and typical/atypical medullary features (Figure 1).
What is a basal-like phenotype?
Basal-phenotype or basal-like breast cancers are characterized by basal epithelium cytokeratin (CK5/14/17) expression, negative estrogen receptor (ER) status and distinct gene expression signature.
How is immunohistochemistry done?
A laboratory method that uses antibodies to check for certain antigens (markers) in a sample of tissue. The antibodies are usually linked to an enzyme or a fluorescent dye. After the antibodies bind to the antigen in the tissue sample, the enzyme or dye is activated, and the antigen can then be seen under a microscope.
What is a basal marker?
Purpose: Basal marker expression in triple-negative breast cancers identifies basal-like tumours, and thus separates the TN group into two prognostic groups. However, the expression and prognostic significance of basal markers in luminal breast cancers are poorly described.
What causes basal breast cancer?
A basal breast cancer probably derives from a stem or progenitor cell that has never expressed ER. BRCA1 breast cancers derive from an ER-negative luminal progenitor [71, 72]. BRCA1 may be required for the transition from an ER-negative to an ER-positive progenitor [73].
What is basal subtype?
The basal subtype, which represents 15-25% of cases, is characterized by an expression profile similar to that of myoepithelial normal mammary cells. Basal tumors are frequently assimilated to triple-negative (TN) breast cancers.
Which of the following is the first step in immunohistochemistry?
The first stage of IHC is the application of a primary antibody that binds specifically to the target antigen. There are two main types of antibody, polyclonal and monoclonal.
What is basal-like breast cancer?
Basal-like breast cancer comprises 15% to 20% of all breast cancers and, like TNBC, tends to occur in younger premenopausal women of African American and West African descent. Basal-like cancers generally have a poor prognosis. The tumors tend to carry tumor protein p53 ( TP53) mutations. Histologically, they share features with TNBC.
What is the best panel of antibodies to diagnose basal-like breast cancer?
The best currently known panel of antibodies which is routinely used to diagnose the basal-like subtype of breast cancer has been proposed by Nielsen et al. It comprises four antibodies (ER, EGFR, HER2 and CK5/6) and shows 100% specificity and about 76% sensitivity.
Which biomarkers are expressed by basal-like breast cancers?
Biomarkers expressed by basal-like breast cancers include CK 5&6, CK 14, CK 17, laminin, EGFR, fatty acid binding protein, p16, and p53. 10,11 Furthermore, there is a significant number of triple-negative cancers that do not express basal markers and are classified as normal breast-like.
Which immunohistochemical markers are used to diagnose breast cancer?
The most common immunohistochemical breast cancer prognostic and therapeutic markers used include: estrogen receptor, human epidermal growth factor receptor-2, Ki-67, progesterone receptor, and p53. In addition, markers of angiogenesis and apoptosis are also important. INTRODUCTION