INTRODUCTION: Leptomeningeal metastases ( (LM) occurs in approximately 5% of individuals diagnosed with metastatic breast cancer (BC). Both systemic and inthratecal (IT) agents can be used for treatment. However, data to support the effectiveness of IT therapy are insufficient. The primary aim of this study was to assess the efficacy and safety of IT therapy in BC patients with LM.
METHODS: This was a retrospective observational study. SPSS version 27 was used for statistical analysis. Kaplan–Meier and Cox regression analyses were used for survival analysis.
RESULTS: The study included 14 patients (median age, 52 years). The predominant histopathological types were invasive ductal carcinoma (57%) and invasive lobular carcinoma (36%). IT methotrexate was used in 9 (64%) patients, and IT trastuzumab was used in 5 (36%). Notably, 36% of patients achieved a partial response, 14% achieved a stable response, and 50% showed disease progression. It was found that approximately 50% of patients with positive cerebrospinal fluid (CSF) cytology became negative after treatment. Furthermore, toxicity of grade 2 or higher was observed in 49% of patients. The median progression-free survival (PFS) duration among patients who received methotrexate was 1.46 months (95% CI, 0.29–2.0) and among those who received trastuzumab was 5.1 months (95% CI, 0–13.1). The median overall survival (OS) duration among all patients was 3.8 months.
DISCUSSION AND CONCLUSION: LM is an indicator of poor prognosis among patients with breast cancer. However, IT therapy is one of the few treatment options. IT trastuzumab should be considered as a treatment option in HER2-positive BC patients with leptomeningeal metastasis.