The role of molecular information to guide treatment decisions has become increasingly important for patients with breast cancer.
Molecular assays that enable clinicians to quantify patients’ risk of disease recurrence have been commercially available for over a decade, and some have received long-standing recommendations in clinical guidelines. These assays are used to identify patients who may or may not benefit from adjuvant chemotherapy in addition to endocrine therapy, and are utilized routinely in clinical practice.
EndoPredict (EPclin), a breast cancer prognostic test, analyzes RNA expression of 8 target genes, 3 normalization genes, and 1 control gene, creating a 12-gene molecular score, which is then combined with clinical features of the tumor (tumor size and nodal status) to predict the 10-year distant recurrence (DR) rate. This information may be used by treating physicians to guide therapy decisions by identifying which patients have sufficiently low risk of DR and may safely forgo chemotherapy, and which patients are at high risk for DR and may need adjuvant chemotherapy in addition to endocrine therapy.