Histological Characterization of 47 Breast Cancers with Neoplastic Meningitis Evolution.

Abstract

Abstract IntroductionAround 5% of patients with breast cancer develop neoplastic meningitis (NM). The prognosis of NM in this population is supposed to be better with a median survival time of 7 months if treated with intrathecal therapy, systemic treatment and adapted supportive care (versus 4-6 weeks if untreated). This evolution needs to be detected as early as possible and it is necessary to identify tumors with such a risk. We report histological characteristics in 47 breast cancers with leptomeningeal treated in our institution for the last 2 years.Aim of the studyTo identify histopathological characteristics of breast cancer predictive of leptomeningeal evolution.Patients and methods47 consecutive female breast cancer patients were diagnosed with neoplastic meningitis on the basis of cerebrospinal fluid (CSF) cytology and/or cerebrospinal MRI plus clinical symptoms. These patients were matched with 47 breast cancer's patients without leptomeningeal evolution, according to age at breast cancer diagnosis (+/- 2 years), year of breast cancer diagnosis (+/- 2 years) and use of systemic chemotherapy as initial treatment of breast cancer. Differences between the 2 groups of patients were analyzed using usual statistical methods (t-test, Chi square test).ResultsAt the time of NM diagnosis, the median (min-max) age of patients with NM was 51 (26-76) years. Median delay after breast cancer diagnosis was 33 months (0-193). Brain, hepatic, bone, lung metastases were present in respectively 47%, 43%, 47% and 19%. CSF cytology was positive in 72%, median proteinorachia was 0,75 g/l (0,17–16,12); cerebrospinal MRI was also positive in 87%. At the time of breast cancer, median age was 49 (25-70) years. Initial breast samples were tumor biopsy in 43%, partial mastectomy in 31% and total mastectomy in 27%. Breast tumors were invasive ductal carcinoma in 84% with histoprognostic grade II/III in 49/42%, MSBR grade I/II in 52/47%. Grade 3 of differentiation was observed in 68%, grade 3 of anisonucleosis in 59% and grade 1 of mitosis in 48%. In the tumors, estrogen/progesterone receptors (ER/PR) were detected in 67/48% and HER2 overexpression was observed in 24%. 19% of the tumors were triple negative. Vascular emboli were detected in 58% of the cases. Tumors were T2 in 43%, N+ in 66% and M+ in 14%. Significant differences between initial breast cancers with or without NM evolution concerned histological type (p = 0,043), ER (p = 0,004) and PR (p = 0,023), triple negative status (p = 0,009) and initial metastatic status (p < 0,007).ConclusionsCarcinomatous meningitis preferentially occurs in invasive lobular tumors without hormonal receptors, particularly in triple negative tumors and in tumors metastatic upfront. HER2 overexpression is not a risk factor of NM, as is observed with brain metastases. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6013.