Characteristics and prognosis of leptomeningeal metastasis in patients with breast cancer

Abstract

Background: The incidence of leptomeningeal metastasis (LM) in breast cancer is reported to be approximately 5% and prognosis of breast cancer patients with LM is poor. Characteristics and treatment for breast cancer with LM remain unclear. The objective of this study is to observe outcome of breast cancer patients with LM in the current background. Patients and Methods:We retrospectively reviewed 84 breast cancer patients who were diagnosed with LM and received treatment for LM between 2005 and 2018 in our institution. LM was diagnosed by brain imaging and/or lumbar puncture with the presence of malignant cells in cerebrospinal fluid. Result(s): Median age at diagnosis of LM was 56.5 years (33-76). Thirty-nine (46%), 7 (8%), 12 (14%), and 24 (29%) were HR+/HER2-, HR+/HER2+, HR-/HER2+ and triple negative, respectively. Median time to LM from the diagnosis of distant metastasis was 66.6months, and significantly longer in HR+/HER2+ compared with other subtypes (p<0.0045). Twenty-four (29%) women had developed brain metastasis at diagnosis of LM. Of 84 patients, 72 patients (85.7%), 4 (4.8%), and 8 (9.5%) were treated with radiotherapy (RT), IT, and RT+IT, respectively. Median overall survival (OS) was 3.8 months, with 11 patients (13%) surviving longer than 1 year. In univariate and multivariate analysis, higher performance status (PS), and RT with planned dose were positive prognostic factors for OS (p=0.027 and p<0.001). Median survival of RT+IT patients was 11.9 months, 1.7months for IT and 3.7 months for RT patients (p=0.132). Six months survival rate following LM were 26.7% for RT, 0% for IT and 53.6% for RT+IT respectively. Age, HR, and HER2 status, breast cancer subtype, cranial only involvement and neurological findings were not associated with OS. Conclusion(s): Survival following a diagnosis of LMin breast cancer patients remains poor, but some patients survived more than 1 year in this study. PS and RT with planned dose were independent prognostic factors.