281MO - Clinicopathological characteristics and prognosis of breast cancer patients with isolated central nervous system metastases in the multicentre ESME database

Background

As a result of therapeutic and diagnostic advances, there is an increase of metastatic breast cancer (MBC) with first isolated central nervous system (CNS) metastases, for which there is no standard of care. The present study describes the largest-to-date real-life cohort of MBC patients with this clinical picture.

Methods

We retrospectively analyzed data from the ESME MBC French database including pts who initiated care for MBC between 2008-2016. The primary objective was to report the characteristics, management, and outcomes of those with first isolated CNS metastases, excluding pts with intrathecal treatment (IT) for leptomeningeal disease. Progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier method. Descriptive statistics and multivariate Cox model were used.

Results

Of the 22,266 pts in the database, 541 (2.4%) had first isolated CNS metastases and no IT: median age was 57 years, median time to MBC, 22.8 months (mo). HER2+ cases were more frequent than the triple-negative (TN) or HR+/HER2- ones (41.6% vs. 26.1% vs. 28.5%, p<0.01). Treatment consisted of both local and systemic therapy (49.5%), only local (17.9%), only systemic (11.5%), or no treatment (18.5%). After a median follow-up of 43.3 mo, median first-line PFS and OS were 6.1 mo (95%CI: 5.7-6.8) and 20.7 mo (95%CI: 17.3-24.3). Older age, TN subtype, MBC-free interval (6-12 mo), lower PS and whole-brain radiotherapy were associated with worse survival by multivariate analysis. Median OS in the HR+/HER2+, HR+/HER2-, HR-/HER2+ and TN subgroups were 37.9 mo (95%CI: 25.9-47.6), 22.9 mo (95% CI: 17.1-31.9), 19.2 mo (95% CI: 14.3-28.9) and 11.5 mo (95%CI: 9.6-15.4), respectively. Compared with none, the use of systemic therapy within 3 months was associated with a better median OS by univariate analysis (24.1 vs. 16.1 mo (HR=0.8 [95%CI: 0.6-1.0], p=0.031), not confirmed by multivariate analysis (HR=1.0 [95%CI: 0.7-1.3], p=0.806).

Conclusions

MBC patients with first isolated CNS metastases, excluding leptomeningeal disease, represent a distinct population with specific management. In this context, the role of systemic therapy needs to be further investigated in prospective studies.

Clinical trial identification

NCT03275311.

Editorial acknowledgement

Legal entity responsible for the study

UNICANCER.

Funding

UNICANCER. The ESME MBC database receives financial support from an industrial consortium (Roche, Pfizer, AstraZeneca, MSD, Eisai and Daiichi Sankyo). Data collection, analysis and publication are managed entirely by R&D UNICANCER independently of the industrial consortium.

Disclosure

A. Patsouris: Travel/Accommodation/Expenses: Roche; Travel/Accommodation/Expenses: Pfizer; Research grant/Funding (institution), Travel/Accommodation/Expenses: Eisai; Honoraria (institution): Lilly. C. Levy: Honoraria (self): Pfizer; Honoraria (self), Travel/Accommodation/Expenses: Roche; Honoraria (self): MSD; Honoraria (self), Travel/Accommodation/Expenses: Lilly; Travel/Accommodation/Expenses: Daiichi. A. Gonçalves: Travel/Accommodation/Expenses: Roche; Travel/Accommodation/Expenses: Pfizer; Honoraria (institution), Research grant/Funding (institution), Travel/Accommodation/Expenses: Novartis; Travel/Accommodation/Expenses: AstraZeneca; Honoraria (institution), Research grant/Funding (institution): MSD; Honoraria (institution): Lilly. T. Bachelot: Honoraria (self), Research grant/Funding (institution), Travel/Accommodation/Expenses: Novartis; Honoraria (self), Travel/Accommodation/Expenses: Roche; Honoraria (self), Research grant/Funding (institution), Travel/Accommodation/Expenses: Pfizer; Honoraria (self), Research grant/Funding (institution), Travel/Accommodation/Expenses: AstraZeneca; Honoraria (self): Seattle Genetics. All other authors have declared no conflicts of interest.