Implication of breast cancer phenotype for patients with leptomeningeal carcinomatosis

We aimed to study the implications of breast cancer (BC) subtypes for the development and prognosis of leptomeningeal carcinomatosis (LC).

Data from the breast cancer patients diagnosed with LC between 2005 and 2010 were retrieved. Patients were classified in luminal A, B, HER2 positive and triple negative (TN) and their BC diagnosis, treatment, and outcome were analyzed according to each subtype. Pearson's chi-square and Fisher's exact test were used for categorical variables. Survival analyses were performed by Kaplan-Meier method and compared with the log-rank test.

A total of 38 BC patients were identified, with a median age of 54.8 years (range 36-79). The proportion of luminal A, B, HER2 positive and TN was 18.4%, 31.6%, 26.3% and 23.7%, respectively. LC was the first evidence of metastatic disease in 5 BC patients. Twenty patients received the systemic chemotherapy, with 16 (80%) whole brain radiotherapy (WBRT). Nine patients received only WBRT. TN patients had the shorter interval between metastatic breast cancer diagnosis and the development of LC. Median survival after the diagnosis of LC (OSLC) was 2.6 months (range 1.2-6.4), and did not differ across breast cancer subtypes. In univariate analysis, performance status (ECOG = 0-2) and chemotherapy were prognostic for OSLC, but only the treatment stood as an independent prognostic factor in multivariate analysis.

Breast cancer subtype influences the timing of LC appearance, but not OSLC. Patients with LC from breast cancer should be offered systemic treatment, as it appears to associate with the improved outcome. New therapeutic strategy, including, targeted and intrathecal therapy are deserved for BC patients with LC.