Clinicopathological Features, Treatment Modalities, and Prognostic Factors of Leptomeningeal Carcinomatosis in Patients with Breast Cancer: A Single-Center Retrospective Analysis

Abstract

Aim: Leptomeningeal metastasis (LM) from breast cancer carries a poor prognosis, and most published cohorts originate from high-volume referral centers. We aimed to identify factors associated with overall survival (OS) after an LM diagnosis in routine practice and to describe diagnostic and treatment patterns.Methods: We retrospectively reviewed consecutive women treated for breast cancer–related LM at a single tertiary center between February 2018 and December 2023. LM was classified according to the European Association of Neuro-Oncology–European Society for Medical Oncology criteria. OS was measured from the LM diagnosis and estimated by the Kaplan–Meier method. Candidate variables were examined by Cox regression. Landmark analyses at 4 weeks were used to limit immortal time bias.Results: Thirty-eight women were included; median age at LM diagnosis was 57.0 years. The diagnosis was cytologically or histologically confirmed (type I) in 12 patients (31.6%). After the LM diagnosis, 32 patients (84.2%) received systemic therapy, 22 (57.9%) radiotherapy, and 5 (13.2%) intrathecal methotrexate. Thirty-five patients (92.1%) had died. Median OS was 2.8 months (95% confidence interval [CI], 1.4–8.8); 6- and 24-month survival were 39.5% and 12.3%, respectively. No variable reached P < 0.10 in univariable analysis; radiotherapy had the lowest P value (hazard ratio 0.57; 95% CI, 0.28–1.15; P = 0.11). An exploratory multivariable model, specified before fitting, showed no independent association.Conclusions: Median survival was 2.8 months, and no independent prognostic factor was identified. The low rate of cytological confirmation limits comparison with referral-center series.