Development of a prognostic score for meningeal carcinomatosis in patients with advanced breast cancer

Purpose Meningeal carcinomatosis carries a dismal prognosis in patients with breast cancer, and requires invasive therapies. The aim of the present retrospective study was to elaborate a prognostic score of overall survival in patients with breast cancer related meningeal carcinomatosis (MC). Methods 109 patients with proven breast cancer MC, treated by at least one intrathecal (IT) injection of methotrexate or thiotepa at Institut Curie were retrospectively recorded from 2011 to 2019. We developed prognostic clinical scores for overall survival and 24-weeks survival. Results Diagnosis and evaluation of meningeal carcinomatosis appears based on a combination of clinical, imaging and laboratory studies. Three significant Overall Survival (OS) prognostic factors were identified. Clinical response or stabilization at one month of intrathecal therapy had a favorable independent prognostic value for both overall and 24-weeks survival. Additionally, baseline CSF Cyfra 21 − 1 level lower than 79 ng/mL in the cerebrospinal fluid and absence of 1-month cerebrospinal fluid (CSF) malignant cells carried a borderline favorable independent prognostic value for overall and 24-weeks survival, respectively. We constructed 2-class and 3-class prognostic scores for each outcome, identifying a very poor prognosis population. Conclusions To our knowledge it is the first study to develop a response-based prognosis score in patients with breast cancer related MC. This one month prognostic score may help to decide which patient could actually benefit from the prolongation of intrathecal therapy.