Tissue Evaluation for HER2 Tumor Marker

Excerpt

The human epidermal growth factor receptor-2 (HER2) receptor (previously called HER2/Neu) is a transmembrane glycoprotein with tyrosine kinase activity that belongs to the epidermal growth factor receptor family. These receptors are essential in controlling epithelial cell growth and differentiation. These receptors are important, as aberrant HER2 protein overexpression has associations with some adenocarcinomas, including breast, ovary, endometrium, cervix, as well as lung, esophageal, gastroesophageal junction, gastric, and bladder cancers. HER2 amplification or overexpression occurs in approximately 20% to 30% of human breast cancers. This protein is strongly associated with increased disease recurrence and is a poor prognostic factor for survival. For this reason, HER2 is an essential target for the therapy of various types of cancer.