Abstract
BACKGROUND
The majority of breast cancer patients with brain metastases receive wholeโbrain radiotherapy (WBRT) and have a survival of only a few months. A short WBRT regimen would be preferable if it provides survival that is similar to that achieved with longer programs. This retrospective study compared survival and local control within the brain resulting from shortโcourse WBRT with longer programs in 207 breast cancer patients.
METHODS
Sixtyโnine patients treated with 5 fractions of 4 grays (Gy) each given within 5 days were compared with 138 patients treated with 10 fractions of 3 Gy each given over 2 weeks or 20 fractions of 2 Gy each given over 4 weeks. Six additional potential prognostic factors were investigated: age, Karnofsky performance score (KPS), number of brain metastases, the presence of extracranial metastases, interval from tumor diagnosis to WBRT, and recursive partitioning analysis (RPA) class.
RESULTS
On univariate analysis, the WBRT regimen was not found to be associated with survival (P = .254) or local control (P = .397). Improved survival was associated with a KPS >70 (P < .001), single brain metastasis (P = .023), the absence of extracranial metastases (P < .001), and lower RPA class (P < .001). On multivariate analysis, which was performed without RPA class because this is a confounding variable, KPS (relative risk [RR] of 4.00; P < .001) and the presence of extracranial metastases (RR of 1.54; P = .024) maintained statistical significance. On univariate analysis, local control was associated with KPS (P < .001) and RPA class (P < .001). On multivariate analysis, local control was found to be associated with a KPS >70 (RR of 5.75; P < .001).
CONCLUSIONS
Shortโcourse WBRT with 5 fractions of 4 Gy each resulted in survival and local control that were similar to longer programs in breast cancer patients with brain metastases. The dose of 5 fractions of 4 Gy each appears preferable for the majority of these patients because it is less time consuming and more convenient. (See editorial on pages 000โ000, this issue.) Cancer 2007. ยฉ 2007 American Cancer Society.