Association between tumor-infiltrating lymphocytes and oncotype DX estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 single gene scores in hormone receptor-positive/HER2-negative breast cancer

In HR+/HER2- breast cancer, tumors with lower HER2 mRNA expression exhibit higher lymphocytic infiltration, suggesting the presence of a distinct immunologically active subset. Oncotype DX single gene scores, particularly HER2, may provide information beyond recurrence risk prediction and help identify patients who may benefit from immune-modulating therapeutic strategies.