Leptomeningeal Metastasis in ER+HER2- Advanced Breast Cancer Patients: A Review of the Cases in a Single Institute Over a 14-year Period
Abstract Purpose: While leptomeningeal metastases (LM) from estrogen receptor-positive, HER2-negative advanced breast cancer (ER+HER2-ABC) has a poor prognosis, the details of LM ER+HER2- are unclear. We therefore retrospectively investigated patients with LM from ER+HER2-ABC.Methods: ER+HER2-ABC patients who received any therapy at Shizuoka Cancer Center between October 2002 and December 2017 were retrospectively analyzed. Patients with central nervous system (CNS) metastases were divided into three groups: brain metastasis (BM) only (B group); BM with LM (BL group); and LM only (L group).Results: Among 369 patients, 102 developed CNS metastases: 70 (68.6%), 13 (12.8%), and 19 (18.6%) in the B, BL, and L groups, respectively. The L group showed a later onset, poorer performance status, more symptoms, and more skull metastasis than the other groups. Radiotherapy as the initial treatment was introduced to 13/13 (100%) and 15/19 (78.9%) in the BL and L groups, respectively. Subsequent systemic therapy excluding best supportive care was introduced to 5/13 (38.5%) and 5/19 (26.3%) in the BL and L groups, respectively. The median overall survival (OS) from the diagnosis of CNS lesions was 295.0, 146.0, and 99.0 days in the B, BL, and L groups, respectively, and worsening of CNS lesions was the major cause of death in the BL and L groups. Multivariate analyses showed that concurrent soft tissue metastasis (hazard ratio, 4.620) and subsequent systemic therapy (hazard ratio, 0.063) were prognostic for the L group.Conclusion: Management of LM from ER+HER2-ABC remains challenging, so a multimodal approach with novel systemic therapy is warranted.