Is another class of molecular targeted therapy an appropriate decision as the next treatment for progressive disease with initial molecular targeted therapy for luminal advanced/metastatic breast cancer?

The sequential use of different classes of MTA did not affect the TTF of another MTA. Therefore, mTOR inhibitor + exemestane is a favorable treatment option administered after CDK4/6 inhibitor + hormone therapy. The CDK4/6 inhibitor + hormone therapy is also suitable for patients previously treated with mTOR inhibitor + exemestane. Despite the retrospective and single-center study design, these findings provide useful information for treatment selection in clinical practice.