Ventriculoperitoneal Shunt for CNS Metastasis in Breast Cancer: Clinical Outcomes Based on Intrinsic Subtype

Leptomeningeal metastasis (LM) is associated with a grave prognosis in breast cancer (BC) and can be controlled with a ventriculoperitoneal shunt (VPS). Information regarding LM and VPS based on intrinsic subtype is limited; thus, we investigated the clinical outcomes of BC treated with VPS.

The present retrospective study comprised 70 patients diagnosed with LM who received a VPS. The patients were divided into 4 groups based on BC subtype: hormone receptor (HR)⁺/human epidermal growth factor receptor 2 (HER2)^-, HR⁺/HER2⁺, HR^-/HER2⁺, and triple negative BC (TNBC).

The most common indications for VPS were uncontrolled intracranial pressure (57.1%) and uncontrolled headache (55.7%), which improved in 54 (77.1%) of 70 patients after VPS. The median overall survival (OS) after brain or LM and overall survival after VPS were 7.6 and 2.3 months, respectively. Anti-HER2 treatment was a significant prognostic factor for better OS after brain or LM based on multivariate analysis (hazard ratio, 0.15; 95% confidence interval, 0.04-0.57; P = .005), whereas TNBC was correlated with shorter OS after central nervous system metastasis (hazard ratio, 2.82; 95% confidence interval, 1.46-5.48; P = .002).

There were significant differences in clinical outcome based on the intrinsic subtype of patients with BC with LM who received a VPS. Anti-HER2 treatment in patients with HER2⁺ BC was associated with better survival in patients with metastatic BC with VPS insertion compared with those without. Survival of metastatic BC with VPS remained poor, especially in the TNBC subgroup.