The number of involved extracranial organs: A new predictor of survival in breast cancer patients with brain metastasis

Objective This study was performed to investigate the potential impact of the number of involved extracranial organs on survival in patients with brain metastasis from breast cancer. Methods The data of 196 patients treated with whole-brain radiotherapy (WBRT) alone for brain metastases from breast cancer were retrospectively analyzed. Six potential prognostic factors were evaluated for associations with survival. These factors included WBRT regimen, age, Karnofsky performance score (KPS), number of brain metastases, interval from breast cancer diagnosis to WBRT, and the number of involved extracranial organs. Results The 6-month survival rates of patients with involvement of 0, 1, 2, 3 and ≥4 extracranial organs were 59%, 49%, 26%, 26% and 13%, respectively, and the 12-month survival rates were 45%, 36%, 17%, 17% and 13%, respectively (p < 0.001). On multivariate analysis, the number of involved extracranial organs (risk ratio 1.17; 95%-confidence interval 1.02-1.35; p = 0.028) maintained significance, as did KPS (p < 0.001), but not age (p = 0.27). Conclusion The number of involved extracranial organs is an independent prognostic factor of survival in patients with brain metastasis from breast cancer.