Clinical Outcomes and Prognostic Factors in HER-2 Positive Breast Cancer with Brain Metastasis: A Single-centre Experience.

Objective:  To determine the characteristics and prognosis of brain metastasised HER-2 positive breast cancer (BC) patients.

Study Design: Descriptive study.

Place And Duration Of Study: Ankara Oncology Training and Research Hospital, Turkey between 2000 and 2019.

Methodology: HER-2 positive BC patients were analysed retrospectively and 105 patients were included in the study. Age 18 years and over, HER-2 positive BC, with BM (brain metastases) were the inclusion criteria. Patients with secondary malignancies, those with missing data, and irregular follow-up were excluded from the study. The age, type of treatment, Eastern Cooperative Oncology Group Performance Status (ECOG PS) score, BM date, and the last contact date of the patients were obtained from the hospital records. The Kaplan-Meier method was used to determine the time to BM and OS. Independent factors affecting OS and time to BM were determined using the Cox regression model.

Results: Patients with ECOG PS score of 0-1 at the time of the BM had 19 months median overall survival (OS), while patients with ECOG PS score of 2 had 8 months (p <0.01). Median OS after BM was 32 and 14 months for patients with one BM and patients with multiple BM, respectively (p <0.01). Multivariate cox regression analyses revealed that time to progression of BM was shorter in patients with high-grade tumors compared to patients with low-grade tumors (p= 0.048), and in patients with de-novo metastasis compared to patients without de-novo metastasis (p= 0.003). Conclusıon: Tumor grade and de-novo metastasis (extracranial metastasis at the time of diagnosis) are independent predictive factors that may cause the earlier occurrence of BM and affect mortality in BC patients. Key Words: Brain metastasis, Breast cancer, HER-2 positive, Metastasis.