Identifying Biomarkers to Select Patients with Early Breast Cancer Suitable for Extended Adjuvant Endocrine Therapy.

Postmenopausal women with early oestrogen receptor-positive breast cancer who have received 5 years of endocrine therapy are at increased risk of developing a recurrence. An important clinical question is how to identify women who are at highest (or lowest) risk of a recurrence. The use of prognostic biomarkers allows individualised breast cancer therapy but correct identification of patients who will benefit most from extended endocrine therapy is essential. Several multigene assays have been developed to determine the likelihood of overall recurrence but so far none exist specifically for the prediction of late recurrence. Recent results from large clinical trials have shown that biomarker assays that include clinical information in their tests might be useful to predict and risk stratify patients for late recurrence. However, further research is needed to specifically offer multigene assays for the identification of late recurrence and thus justify routine use of these tests in the clinical setting.