Effect of early detection of occult brain metastases in HER2-positive breast cancer patients on survival

Abstract

1015 Aim: The aim of the study was to compare disease free survivals (DFS), survivals from the detection of brain metastases, overall survivals (OS) and the causes of death between two patient groups: group I with disseminated HER2-positive breast cancer and occult brain metastases and group II with symptomatic brain metastases. Material and Methods: MRI screening of the brain was performed in 80 HER2-positive breast cancer pts treated with trastuzumab and cytostatics for visceral metastases. In 29 pts (34%) in whom occult brain metastases were detected, whole brain radiotherapy (WBR) to the brain (30 Gy in 10 fractions) was performed (Group I). They were compared with 48 pts with symptomatic brain metastases treated at the same clinic during the same time period (Group II). Both groups were comparable regarding the site of distant metastases and the type of treatment. All pts in both groups had distant metastases to the lung and/or liver. Results: Median DFS in group I was 17 months and in Group II- 19.9 months (p=0.61). Median survival from dissemination of the disease (visceral metastases) to the detection of occult and symptomatic brain metastases was 9 and 15 months, respectively (p=0.21). Median survival calculated from the detection of brain metastases was 9 and 9.3 months, respectively (p=0.76). Median OS of pts with occult and symptomatic brain metastases was 53.8 and 52 months, respectively (p=0.79). In the group with occult brain metastases 15% of pts died because of progression in the brain and in the group of symptomatic brain metastases the rate of cerebral death was 48%. Conclusions: WBR performed during the asymptomatic period decreased the rate of cerebral deaths, but did not prolong overall survival. Screened MRI of the brain during the asymptomatic period did not improve the outcome of pts with HER2-positive breast cancer and with visceral metastases. No significant financial relationships to disclose.