ABSTRACT
Molecular-based medicine has the potential to revolutionize the impact that tissue-based assays have on patient management. Assays for HER2/neu and hormonal receptors are forerunners of many more predictive assays that are likely to trickle down to clinical utility in the very near future, many of which will require quantitative analysis. However, cellular pathology has largely operated for many years on subjective analysis and rarely employed quantitation. Consequently, there has been and currently continues to be much controversy over the lack of reproducibility between different institutions when assaying for biomarkers such as estrogen receptors (ER) or HER2/neu.
