Management of brain metastases in patients with HER2 positive breast cancer – a real world Australian experience
Approximately one third of women with HER2 positive metastatic breast cancer (MBC) will be diagnosed with brain metastases (BM), and progression in the central nervous system has become the major life-limiting problem. We analysed data from BioGrid’s® “Treatment of Advanced Breast Cancer in the HER2 Positive Australian Patient” (TABITHA) registry to characterize the impact of newer systemic anti HER2 therapies on this group.
Data collected from 10 Australian sites participating in the registry was analysed. Patient, tumour characteristics, treatment and outcome data were evaluated for patients with and without brain metastases.
Of 204 patients in TABITHA, diagnosed between 2007 and 2017, we identified 59 patients (29%) diagnosed with BM, of which 22 (10%) had BM at the initial diagnosis of metastatic disease. 41 of 59 patients with BM had initially presented with early breast cancer. The majority (41/59) were managed non-operatively. Radiation was used in 47/59 patients, with 12 receiving WBRT and 35 receiving SRS. 9 of 22, 40%) of patients with BM at initial diagnosis received the first line combination of Paclitaxel, Pertuzumab and Trastuzumab. At a median follow-up for the BM cohort of 30.7 months the mean survival was 41 months, which is not inferior to the mean survival for patients without BM. The HR for BM patients was 1.27 (0.92-1.74).
Our data confirms the high prevalence of BM in the HER2 positive MBC population. Survival for HER2 positive patients with BM is not statistically inferior to non BM patients. We will continue to use the TABITHA database to monitor response of BM to systemic and local therapies.
The TABITHA registry is sponsored by BioGrid Australia and has received financial support from Roche Products Pty Limited.