Use of the Gene Expression Test Prosigna ® in Premenopausal Patients with HR+, HER2- Early Breast Cancer: Correlation of the Results with the Proliferation Marker Ki-67.

According to the present study, there is only limited concordance regarding the risk group stratification between Ki-67 and Prosigna-based risk assessment. The relevance and frequency of premenopausal breast cancer emphasizes the need for further evaluation of gene expression analyses in this setting and the correlation with classic clinicopathological parameters regarding therapy decision-making.