Intrinsic Subtypes of Primary Breast Cancer--Gene Expression Analysis

Intrinsic subtypes based on gene expression have substantially improved the understanding of the biological diversity and heterogeneity of breast cancer. The efficacy of adjuvant therapies depends on the level of risk for an individual patient. Because of this, careful estimation of the level of risk is mandatory. In addition to well-established clinicopathological factors, validated gene expression signatures are useful especially in estrogen receptor-positive and HER2-negative patients. Commercially available gene expression signatures like Prosigna, MammaPrint, Oncotype DX, and EndoPredict are recommended by the Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) for use in selected patients.