The American Cancer Society estimated that there were over 200,000 new cases of breast malignancy diagnosed in 2009, with an estimated 40,000 women expected to die from this disease each year (American Cancer Society 2009). While nodal status is still the most important prognostic factor in breast cancer, other parameters such as HER2 expression are known to impact disease recurrence and ultimately survival (O’Shaughnessy et al. 2006). HER2 is expressed in approximately 70-80% of breast cancers and over-expressed in 20-30% of breast cancers (Slamon et al. 1989).