Retrospective study of leptomeningeal metastasis: unveiling the indolent and rapid progression phases.

Purpose: Leptomeningeal metastasis (LM) is a severe cancer complication with poor prognosis and inconsistent treatment. Most studies are from Western countries, limiting understanding of LM in the Chinese population. This study aims to explore LM characteristics in Chinese patients and develop tailored treatment strategies.

Methods: We retrospectively studied 103 Chinese LM patients, all confirmed by CSF cytology, from 2015 to 2024. Data on demographics, medical history, imaging, and follow-up were gathered. Survival analysis was conducted using the Kaplan - Meier method, and univariate and multivariate analyses were performed to identify prognostic factors. A nomogram was developed, and patients were stratified into risk groups based on these factors.

Results: The median age was 54.99 ± 11.18 years, with 53.4% being female. Lung cancer was the primary tumor in 76.7% of patients. Headache was the most common symptom. The median survival was 441 days. Primary tumor site, CSF tumor cell proportion, and asymptomatic status at diagnosis were independent prognostic factors. The nomogram's C - index was 0.81. We identified two distinct groups of LM patients with markedly different characteristics, which we designated as the indolent and rapid progression phases of LM.

Conclusions: The clinical characteristics of LM patients with positive CSF cytology at the center were described, with a longer median survival than previously reported. The developed nomogram demonstrated potential clinical predictive value. Two distinct LM patient groups were identified: the indolent and rapid progression phases, which hold significant clinical relevance.