Lymphopenia: A new independent prognostic factor for survival in patients treated with whole brain radiotherapy for brain metastases from breast carcinoma

Background and purpose: To determine overall survival (OS) and independent prognostic factors in patients with brain metastases (BM) from breast cancer treated by whole brain radiotherapy (WBR). Patients and methods: One hundred and twenty (120) women with BM, treated in a single French cancer center between 02/91 and 06/01, were reviewed. BM were confirmed by computed tomography or magnetic resonance imaging. Survival time was defined as the time interval from the date of BM to the date of death or last follow-up. A Cox proportional hazards regression model was used to determine significant prognostic factors in a multivariate analysis. Results: Surgery was followed by WBR in 5 patients. One hundred and four (104) patients received exclusive WBR, eight received concomitant chemo-radiation, and one received chemo-radiation after surgery. The median survival time was 5 months (95% CI: 3-7 months). In the multivariate analysis, performance status over 1 and lymphopenia (<0.7 G/L) were found to be independent prognostic factors for poor survival. Based on the number of these independent prognostic factors, we propose a predictive model for survival in brain metastatic cancer patients. Median survival was 7 months for patients presenting none or one poor prognosis factor at diagnosis versus 2 months for patients with 2 poor prognosis factors (p<0.0001) Conclusion: Brain metastases from breast cancer remain associated with very poor prognosis and there is a need for better treatment procedures. If confirmed in predictive models, the identification of prognostic subgroups, based on KPS and lymphopenia, among patients with BM from breast cancer would help physicians select patients for future clinical trials