Abstract OT1-07-01: MRI screening versus symptom-directed surveillance for brain metastases among patients with triple negative or HER2+ metastatic breast cancer: A pilot study (nct03881605)

Abstract

Abstract Background: The incidence of brain metastases (BrM) has steadily increased over time as women with metastatic breast cancer (MBC) live longer and survive to experience spread of cancer to the central nervous system (CNS). Women with triple negative and HER2+ MBC, which represent 30-40% of the MBC population, are at particularly high risk of BrM. At present, MBC patients are not screened for BrM; rather, they undergo imaging of the brain only after symptoms suggestive of CNS involvement develop. Unfortunately, by the time that patients experience potentially debilitating symptoms of BrM, they often have a significant burden of disease with limited treatment options and a poor prognosis. We hypothesize that early detection of BrM via magnetic resonance imaging (MRI)-based screening may allow for early intervention and, ultimately, improved outcomes for MBC patients. Methods: A multi-centre, open-label prospective phase II study, randomizing 50 women with triple negative or HER2+ MBC to either MRI-based BrM screening or symptom-directed surveillance. Randomization is stratified for tumor subtype. Intervention arm: Contrast-enhanced MRI of the brain at baseline, 4-, 8- and 12-months with concurrent chemical exchange saturation transfer (CEST) imaging, a new metabolic MRI sequence that may detect BrM even earlier than standard MRI. Control arm: Symptom-directed surveillance (brain imaging only if patients develop symptoms suggestive of BrM). All participants complete questionnaires at baseline, 6- and 15-months to assess overall (EORTC QLQ BN20) and neurologic-specific (FACT-BR tools) quality of life (QoL) as well as cancer-related anxiety (NCI PRO-CTCAE). A blood sample is collected for ctDNA analysis at baseline in all patients at diagnosis of BrM, if applicable. Key inclusion criteria: 1) Age ≥18; 2) Triple negative MBC, with metastatic disease diagnosed ≤12 weeks prior to study entry OR HER2+ MBC with no restrictions regarding timeline of diagnosis; 3) No symptoms of BrM or known asymptomatic BrM at study entry. Key exclusion criteria: 1) ECOG>2; 2) Inability to complete an MRI (e.g., claustrophobia). Analyses: The primary goal of this study is to determine the feasibility of a randomized trial of BrM screening versus symptom-directed surveillance in the proposed patient population. The pilot study will be considered “not feasible” if <30% of eligible patients enroll, <50% complete the study protocol, and/or >50% of patients allocated to the control arm are screened for BrM with CT or MRI. Overall survival will be assessed as a secondary endpoint. We will also investigate how screening for BrM influences the detection rate of BrM and explore how subsequent intervention affects both overall and neurologic-specific QoL. Our data will enable a power calculation to determine a sample size for a future, larger trial. 28 of 50 planned patients have enrolled in the study to-date. Citation Format: Katarzyna J Jerzak, Arjun Sahgal, Gregory Pond, Priscilla K Brastianos, Orit Freedman, Gregory Stanisz, Ellen Warner. MRI screening versus symptom-directed surveillance for brain metastases among patients with triple negative or HER2+ metastatic breast cancer: A pilot study (nct03881605) [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr OT1-07-01.