Adjuvant chemotherapy and survival outcome in node-negative breast cancer with a 21-gene recurrence score of 26-30.

Lay abstract In current clinical practice, the 21-gene recurrence score has been developed for chemotherapy decision-making based on prognostic risk stratification, especially for patients with tumor size ≤5 cm, node-negative, hormone receptor-positive and HER2-negative breast cancer. However, the chemotherapy benefit in breast cancer patients with a 21-gene recurrence score (RS) of 26­30 is unclear. This study aimed to investigate the survival benefit of additional chemotherapy for early-stage breast cancer patients with RS 26­30 using the Surveillance, Epidemiology, and End Results data. Our study suggests that the RS 26­30 group is regarded as a uniform entity by clinicians. Adjuvant chemotherapy improves the outcome for early-stage breast cancer patients with RS 26­30, especially for patients with high-grade tumors.