Brain Metastasis from Breast Cancer: risk factors and radiotherapy perspective from a tertiary Middle Eastern...

Breast cancer represents the second most frequent cause of brain metastases after lung cancer. Previous studies have identified the subgroups of patients with triple-negative and HER2-positive as having an increased risk for the development of brain metastases. We are not aware in Kurdistan - Iraq of any national studies that are in parallel with these findings.

A cross-sectional descriptive study conducted on 57 patients who were known cases of breast cancer with brain metastasis, managed with whole brain radiotherapy at a tertiary radiotherapy institute in two years (January 2015 to December 2016), as a convenient sample. Data were collected from patients' archives and phone calls and then analyzed using SPSS version 23.

Younger age at diagnosis and cancers with HER2-positive receptor phenotype are risk factors for brain metastasis. Median survival post-brain metastasis is significantly affected by receptor phenotypes (2 months in triple negative versus 7 months in hormone receptor positive) and performance status (18 months if performance score of 70% and above versus 1.5 months if it is 60% and less).

Primary breast cancer patients have more risk to develop brain metastases if they are at younger age and HER2-positive and the survival post-brain metastases is dramatically affected by both triple negative receptor phenotype and lower performance score.