RADI-16. Efficacy of WBRT among the Sub-types of Metastatic Breast Cancer

Objectives To understand the effect of Whole Brain Radiation (WBRT) in terms of Age, Neurological performance, Radiological Improvement and the Overall Survival. Methods 34 Patients [Median Age: 45 years (31- 65)] with Metastatic Breast Carcinoma who presented with Brain metastasis to the Department of Radiation Oncology at Kidwai Memorial Institute of Oncology and subjected to Whole Brain Radiotherapy/ Focal RT were taken into the study. The efficacy of WBRT was assessed among the four subtypes of MBC. Results 39% of the patients belonged to Luminal A, 25%, 22% and 14% belonged to Luminal B, Her2 amplified and Basal respectively. Patients under Luminal A, presented with brain metastases by 25 months after the diagnosis of the primary. 60% presented with single lesion, amenable to resection and 58% underwent surgery followed by WBRT and OS fared better as compared to patients with WBRT alone with no distant recurrences on imaging and improvement in KPS. Patients with Luminal B/ HER2 amplified subgroup had predominantly oligometastatic lesions (65%), presented with brain metastases at 15 months after diagnosis of Carcinoma Breast,18% received Herceptin and Lapatinib and 33% and 22% received Herceptin and Lapatinib alone. OS was superior over WBRT alone with exaggerated radiation necrosis in those who took concurrent biological therapy and RT.In patients with Basal subtype,75%had multiple metastatic brain lesions, presented with symptoms by 10 months of diagnosis of the primary with poor KPS and OS remained poor despite WBRT. Conclusions Lesions being amenable for surgery, focal RT to post op cavity alone may be considered in patients with Luminal A. WBRT plus boost for those unfit for surgery. Addition of TKI +/- oral chemo for all patients with Luminal B and HER 2 amplified to Focal RT or WBRT. Triple Negative patients present with poor KPS can be considered for BSC/WBRT on case basis.