Table 2.

Predictive molecular markers of breast cancer.

Predictive molecular markers	Targeted treatment	Detection method	Potential medical use	References
ER	Higher expression of ER in tumor predicts benefit from hormone therapy such as tamoxifen but ER negative tumor benefits more from chemotherapy since they are not stimulated by ovarian sex hormones	IHC	Yes	9,11,31,32,52
Her2	overexpression of Her2 in tumors predicts benefit from targeted therapy like monoclonal antibody (trastuzumab) or by kinase inhibitor (lapatinib) in the metastatic as well as in the adjuvant setting. Her2 negative   tumors benefits from other targeted therapy such as everolimus	IHC and FISH	Yes	8,9,11,14,32
PR	Higher expression of PR in tumor predicts benefit from hormone therapy such as tamoxifen but PR negative tumor benefits more from chemotherapy since they are not stimulated by ovarian sex hormones	IHC	Yes	1,9,11,13,32,42