Molecular Evaluation of Breast Ductal Carcinoma in Situ with Oncotype DX DCIS

A subset of patients with ductal carcinoma in situ (DCIS) of the breast develop ipsilateral invasive breast cancer after breast-conserving surgery with or without adjuvant radiotherapy. Risk assessment and prediction of adverse outcomes for individual patients based on traditional clinical and pathological parameters are limited. The Oncotype DCIS Score is a commercially available multigene assay that has been independently validated in a prospective clinical trial and a population-based cohort. The score helps to identify a subset of women >50 years old with unifocal disease that carries <10% risk of any local recurrence after breast-conserving surgery alone. In this population, individual patients and physicians may consider omitting adjuvant radiotherapy. In this article, we review the literature and summarize the evidence regarding the role of the Oncotype DCIS Score in estimating the risk of ipsilateral local recurrence and ipsilateral invasive breast cancer recurrence. The available data on clinical utility and cost-effective analysis for optimizing decisions on adjuvant treatments are discussed.