Collection of CSF Samples From Participants With Metastatic Triple Negative Breast Cancer (TNBC) and HER2+ Breast Cancer With no Prior History Nor Active Radiographically Detectable Brain Metastases

Background

• Breast cancer (BC) is the most common cancer among women and the second leading cause of cancer-related deaths in women.
• Among the four common metastatic sites of BC - liver, lung, bone, and brain - brain metastases result in the most severe adverse effects and poorest survival outcomes.
• Despite robust preclinical data on potential drugs for brain metastasis prevention, designing prevention trials remains challenging due to the difficulty of identifying high-risk populations, the long time required for outcomes to develop, and the associated costs.
• Circulating-tumor DNA (ctDNA) from cerebrospinal fluid (CSF) collected from patients who had been locally treated for brain metastases and showed no evidence of metastases on MRI displayed a distinct mutation profile compared to plasma collected at the same time.

Primary Objective

-To collect CSF samples from participants with metastatic triple negative breast cancer (TNBC) and HER2+ breast cancer (BC) with no prior history nor active radiographically detectable brain metastases

Eligibility

• Confirmed metastatic HER2+ BC or TNBC
• Age >=18 years

Design

• This pilot, single-site tissue collection trial aims to collect CSF samples for analysis as potential predictors of brain metastases.
• CSF, blood, tumor tissue, and saliva or buccal mucosa will be collected at baseline and optionally during the study.
• All participants will be followed up for brain metastasis development every 6 months for up to 3 years.

• INCLUSION CRITERIA:
• Pathology documentation of histologically confirmed HER2+ BC or TNBC with a history of metastatic disease.
• Participants must be able to undergo lumbar puncture (LP) and brain MRI.
• Women age >= 18 years
• Adequate organ function as defined below:

• Creatinine <=1.5 x institutional upper limit of normal (ULN)

OR

--Calculated Creatinine clearance >=40 mL/min/1.73 m2 for individuals with creatinine levels above institutional ULN (using either Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI] equation)

• Participants must be able to understand and willing to sign a written informed consent document.

Exclusion criteria

• Prior history or current MRI-detected brain metastasis or leptomeningeal disease
• Previous history of any invasive malignancies, except for surgically resected local cutaneous malignancies.
• Pregnancy