Prognostic Markers and Histologic Subtypes in Patients with Meningeal Carcinomatosis in Breast Cancer.

ABSTRACT

OBJECTIVE: Meningeal carcinomatosis (MC) is a rare complication in breast cancer patients. It is defined as a diffuse or multifocal leptomeningeal metastasis. STUDY DESIGN: From our institution database, we retrospectively studied 19 patients diagnosed with MC in the cerebrospinal fluid (CSF) in 1997-2015, in order to evaluate tumor prognostic markers, histologic subtypes, and clinical outcome. RESULTS: All patients were female, with a mean age of 53 years (range 36-75 years). The mean interval between diagnosis of breast carcinoma and MC was 28 months (range 6-62 months). The median survival from the time of diagnosis was 2 months (1-51 months). Sixteen cases (84%) were the ductal phenotype, 62% of which were of a high grade (grade 3), and 3 cases (16%) were lobular. Estrogen and progesterone receptors were positive on immunohistochemistry (IHC) in 53 and 33% of patients, respectively. HER2 IHC was positive (3+) in 20% of the cases; all were amplified by fluorescence in situ hybridization. The incidence of MC in triple-negative tumors was 40%. Twelve patients (63%) already had known metastasis at the time of diagnosis. CONCLUSIONS: Most cases of MC are high-grade ductal. MC is more common in triple-negative breast cancers. The outcome of these breast cancer patients with MC was poor. There was no survival difference according to age, histologic subtype, grade, or hormonal or HER2 status.