Application of 21-Gene test in adjuvant radiotherapy for early breast cancer

Breast cancer is the most common malignant tumor in women. With the development of genomics technology and medical frontier technology, the systemic treatment of breast cancer has gradually entered the era of personalized medicine. However, the decision-making of adjuvant radiotherapy for breast cancer still mainly relies on traditional clinicopathological factors, and there is a lack of scientific and reliable tools to guide precise radiotherapy in different populations. Hormone receptor (HR) positive/human epidermal growth factor receptor 2 (HER2) negative breast cancer is the most common molecular subtype of breast cancer. The 21-Gene recurrence score (RS) test (Oncotype Dx™, Genomic Health, Redwood City, CA) is a commercially available genomic test for breast cancer. In this article, we reviewed the current research evidence on the use of 21-Gene RS test for radiotherapy decision-making in HR-positive HER2-negative early breast cancer. Current clinical studies support the predictive value of 21-Gene RS test for adjuvant radiotherapy, and several large-scale prospective clinical studies in this area are underway.