Effect of chemotherapy on survival after whole brain radiation therapy for brain metastases: a single-center retrospective analysis.

Objective: Whether chemotherapy for systemic disease affects survival of patients with brain metastases or not has not been elucidated before. We performed comprehensive analysis of patients with newly-diagnosed brain metastases primarily treated with whole brain radiation therapy (WBRT) alone.

Methods: Data from 134 patients with newly-diagnosed brain metastases primarily treated with WBRT from 2007 to 2008 was retrospectively reviewed. Univariate and multivariate analyses were performed to identify significant prognostic factors.

Results: Median survival time (MST) of this cohort from the start of WBRT was 5.7 months. MST of patients with RPA Class 1, 2 and 3 were 10.3, 7.8 and 2.2 months, respectively. Multivariate analysis revealed that karnofsky performance status (≥ 70, p < 0.0001), gender (female, p < 0.0001), activity of extracranial disease (stable, p = 0.015), time to develop brain metastasis (<3 months, p = 0.042) and use of chemotherapy after WBRT (multiple regimens, p < 0.0001) were independent prognostic factors for better survival.

Conclusions: Systemic chemotherapy for chemo-responsive cancer prolongs survival despite the presence of treated brain metastases. Irradiated brain metastases will lose their prognostic significance in a large number of patients. Systemic chemotherapy will be a treatment of choice for patients who have systemic disease after WBRT for brain metastases. These results should be validated in the future prospective clinical trials.