Breast cancer is the most common cancer in women. It frequently metastasizes to the lung, liver, and bones. Due to the improvement of therapeutic strategies and therefore longer patient survival, brain metastases have become more frequent. However, evidence-based therapeutic options of systemic treatment are limited because patients with breast cancer brain metastases are often excluded from clinical trials.

Here, we show a patient with brain and orbital metastases from a hormone receptor-positive, Her2neu-negative breast cancer that led to one-sided blindness. She was treated with a combination therapy of the CDK4/6 inhibitor ribociclib and the aromatase inhibitor anastrozole and showed a fast and durable response for 9 months with good tolerability of the treatment.

Systemic treatment with a CDK4/6 inhibitor and endocrine therapy can be considered in breast cancer brain metastases.