Tumor Biomarkers and Prognostic Factors for Breast Cancer

Tumor Biomarkers and Prognostic Factors should be evaluated on all tumor specimens.

Tumor size and grade are the most reliable pathologic predictors of outcome for patients without axillary nodal involvement. The Nottingham score combines histologic grade based on glandular differentiation, mitotic count, and nuclear grade. A higher grade is a poor prognostic factor

a.Hormone receptors.

Expression of estrogen receptors (ERs) and progesterone receptors (PRs) should be evaluated by immunohistochemistry. Intense ER and PR staining is a good prognostic factor.

b.Her2/neu (ERB2):

Her2/neu is a member of the epidermal growth factor family and is involved in cell growth regulation. Overexpression due to gene amplification is seen in approximately 30% of patients with breast cancer. Her2/neu expression is measured by immunohistochemistry; and if equivocal by fluorescence in situ hybridization overexpression of Her2/neu is a poor prognostic factor.

c. Negative markers.

include those tumors that do not express any tumor biomarkers (“triple negative”), the presence of lymphovascular invasion, and other indicators of a high proliferative rate (>5% of cells in the S phase; >20% Ki-67).