ASO Author Reflections: Oncotype DX RS Complementing the Prognostic Stage in the Updated AJCC 8th Edition for T_1-2N₁M₀ ER-Positive HER2-Negative Breast Cancer

Excerpt

The breast cancer staging system used to be based on anatomic factors. Then the molecular subtype based on the validation of biologic markers was introduced to describe the prognosis and treatment benefit.1 The prognostic stage system in the American Joint Committee on Cancer (AJCC) 8th edition for the first time incorporated nearly all the important biologic factors together with anatomic tumor-node-metastasis (TNM) factors. It would be the most accurate predictor of outcome in case of discordance between tumor burden and biology. In this era of precise medicine, clinical and genetic risks should be equally considered. Oncotype DX is the only multigene assay available to improve the classification of the prognostic stage. Cases with T_1-2N₀M₀ estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative cancer and RS lower than 11 should be categorized as pathologic prognostic stage IA. However, the significance of RS has not yet been fully evaluated for lymph node (LN)-positive cases.2^–4 This study aimed to evaluate the prognostic significance of Oncotype DX RS in T_1-2N₁M₀ ER-positive HER2-negative breast cancer based on the pathological prognostic stage using the Surveillance, Epidemiology, and End Results (SEER) database. …