BRAIN METASTASIS OF BREAST CANCER TREATED WITH RADIOSURGERY: SURVIVAL ANALYSIS FROM 2007 TO 2018

Introduction: Metastatic brain tumors outnumber the primary tumors by 10: 1. The best survival rate of brain metastases is represented by female gender, good performance status (PS), primary breast cancer, time between diagnosis of primary tumor and development of brain metastases greater than six months and single lesion. Objectives: To evaluate the epidemiological profile of patients diagnosed with metastatic breast cancer for central nervous system (CNS) undergoing radiosurgery (SRS) and to determine: 1) Overall survival (OS); 2) Brain disease free survival (DFS) after breast cancer diagnosis; 3) Survival after the first SRS and compare them with immunohistochemical data. Methods: Retrospective cohort study of patients diagnosed with brain metastasis of breast cancer treated with SRS in a single institution from 2007 to 2018. Statistical analysis was performed by Fisher‘s test and Kaplan-Meier curve. Results: In a total of 146 patients with CNS metastasis of breast cancer treated with SRS, only 45 patients (30%) received whole brain radiotherapy (WBRT), of which 25 patients were postradiosurgery. The survivals analyzed were: 1) OS, median 46 months (95% CI 38.23-55.36; SD ± 4.37) and mean 44 months (95% CI 41.35-47.21; SD ± 1.49). No difference was found between immunohistochemical subtypes (p = 0.07), being the average for luminal patients was 49 months (95% CI 44.92-5.33; SD ± 2.14), the median for the triple negative was 40 months (95% CI 31.39-50.13; SD ± 4.78) and HER2 was 46 months (95% CI 39.99-5.60; SD ± 3.47). 2) DFS after breast cancer diagnosis, median 23 months 3) Survival after first SRS, median 9 months (95% CI 7.01-10.98; SD ± 1.01) and mean 15 months (95% CI 11.67-19.99; SD ± 2.12). There was no statistical difference between different immunohistochemicals (p = 0.57), being median found for luminal patients was 8 months (95% CI 4.97-11.02; SD ± 1.54), triple negative was 6 months ( 95% CI 3.28-8.71; SD ± 1.38) and HER2 was 10 months (95% CI 7.33-12.66; SD ± 1.36). 4) DFS after radiosurgery, median 6 months (95% CI 4.9-7.03; SD ± 0.52) Conclusion: Radiosurgery is an important therapeutic modality for the treatment of brain metastases in breast cancer, regardless of the immunohistochemical subtype. WBRT can be avoided in 70% of patients, maintaining comparable survival and preventing impairment of neurocognitive function.

Publikationsverlauf

Artikel online veröffentlicht:
23. Oktober 2019