Figure 3.

Data attainability for the clinical questions. Clinical questions were as follows. (A) Is there a difference in survival outcomes between the brain as the primary metastasis site and brain metastasis accompanied by systemic metastasis? (B) Does systemic treatment for brain metastasis patients affect survival outcomes according to subtype? (C) Does the timing of systemic treatment initiation affect survival outcomes when brain metastasis is accompanied by systemic metastasis? and (D) Is there a difference in the prediction of brain metastasis in patients who previously received trastuzumab alone for neoadjuvant therapy and in patients who received pertuzumab and trastuzumab for neoadjuvant therapy? BCBM: breast cancer brain metastasis; HER2: human epidermal growth factor receptor 2; HR: hormone receptor; TNBC: triple-negative breast cancer.