MLTI-14. A SYSTEMATIC REVIEW OF TREATMENT PARADIGMS FOR PATIENTS WITH BREAST CANCER AND ONE OR MORE BRAIN METASTASES

BACKGROUND: Upwards of 50% of patients with advanced breast cancer are diagnosed with brain metastases (BM). Treatment options for these patients have been rapidly evolving due to increased understanding of the tumor pathophysiology and its genetic underpinnings. This systematic review of randomized controlled trials (RCTs) aims to clarify the evidence guiding the treatment of brain metastases from breast cancer. METHODS: MEDLINE, EMBASE, Cochrane Controlled Register of Trials, ClincialTrials.gov, and Web of Science were searched from inception to October 2018 for RCTs comparing treatments for breast cancer BM. We screened studies, extracted data, and assessed risk of bias independently and in duplicate. Outcomes assessed were overall survival (OS), progression-free survival (PFS), and adverse events (Grade 3+). RESULTS: Among 3188 abstracts, only 3 RCTs (N=412; mean sample size per group N=54.7) meeting inclusion criteria were identified. The studies were phase II or III open-label parallel superiority trials. Inclusion criteria among these trials consisted of age >18 with radiologic evidence of >1 BM. Exclusion criteria consisted of poor-performance functional status (ECOG >2 or KPS < 70). The treatment groups included whole-brain radiation therapy (WBRT) vs WBRT + Temozolomide, WBRT vs WBRT + Efaproxiral, and Afatinib vs Vinorelbine vs investigators’ choice (86% of these patients received WBRT or SRS prior to study enrolment). While two trials found no significant difference in OS, one trial found significant improvement in OS with Efaproxiral in addition to WBRT compared to WBRT alone (HR 0.52; 95%CI 0.332–0.816). No significant differences were found with PFS or rate of adverse events amongst treatment groups. CONCLUSION: Considering the high prevalence of breast cancer BM and our improved understanding of genomic/molecular features of these tumors, a greater number of RCTs dedicated at this disease are needed.