HER2: Its Role and Assessment in Breast Cancer Flashcards
what is HER2?
Member of the Epidermal Growth Factor Receptor (EGFR) family of molecules.
what codes HER2?
Encoded for by the HER2 proto-oncogene located on the long arm of chromosome 17
what does HER2 stand for?
Human Epidermal Growth Factor Receptor-2
what are the functions of the EGF family?
As a family they are multifunctional within the cell membrane and are positioned at key stages within cell signalling processes.
what makes up the EGFR family?
- HER1 (EGFR)
- HER2 (c-ERB-b2/neu)
- HER3
- HER4
what are the primary functions of the EGFR family?
- Embryogenesis
- Cell growth
- Cell differentiation
- Apoptosis
what cells does HER2 normally work on?
- Located within a wide range of cell types
– Epithelial
– Breast
– Lung
– Bladder
– Ovary
when has HER2 been over expressed?
the HER2 has been reported as being over-expressed in approximately 20-30% of invasive breast cancer cases, over the last 5-10 years
what is Herceptin?
Monoclonal antibody
how does herceptin become its humanised form?
It retains the mouse hypervariable region, while replacing the rest of the Fab and Fc fragments with the human equivalent. About 95% human.
what is the relationship between herceptin and cardiotoxicity?
Cardiotoxicity has been reported in approximately 4% of breast cancer patients who have undergone Herceptin immunotherapy
what is the 0 category in the staining pattern?
No staining at all or very slight partial membrane staining in less than 10% of tumour cells.
what is the 1+ category in the staining pattern?
Faint barely perceptible membrane staining in more than 10% of tumour cells. Cells stained in only part of the membrane.
what is the 2+ category in the staining pattern?
Weak to moderate complete membrane staining observed in more than 10% of tumour cells.
what is the 3+ category in the staining pattern?
Strong complete membrane staining in more than 30% of tumour cells.
