Detection of selected predictive markers is currently included in the standard diagnostic algorithm of breast carcinoma specimens. Despite this fact we are facing several unresolved questions and issues.
Probably the most frequently discussed predictive marker in breast carcinoma is HER-2/neu. The change of criteria of positivity in 2007 brought several confusions regarding the selection of patients eligible for anti-HER2 treatment.
There is a deficiency of knowledge in tumors with the discordant phenotype (a discrepancy between the results of immunohistochemistry and in situ hybridization). Even in selected HER2 positive patients is the anti-HER2 treatment effective in only 30 % of cases.
Thus, we evidently have to search for new markers which would help to more precisely select the optimal treatment for breast cancer patients.