Prognostic factors for local control and survival after radiotherapy of metastatic spinal cord compression

Purpose: To evaluate potential prognostic factors for local control and survival after radiotherapy of metastatic spinal cord compression (MSCC). Patients and Methods: The following potential prognostic factors were investigated retrospectively in 1,852 patients irradiated for MSCC: age, sex, performance status, primary tumor, interval between tumor diagnosis and MSCC (≤ 15 v > 15 months), number of involved vertebrae (one to two v ≥ three), other bone metastases, visceral metastases, pretreatment ambulatory status, time of developing motor deficits before radiotherapy (faster, 1 to 14 v slower, > 14 days), and radiation schedule (short-course v long-course radiotherapy). Results: On univariate analysis, improved local control of MSCC was associated significantly with favorable histology (breast cancer, prostate cancer, lymphoma/myeloma), no visceral metastases, and long-course radiotherapy. On multivariate analysis, absence of visceral metastases and radiation schedule maintained significance. On univariate analysis, improved survival was associated significantly with female sex, favorable histology, no visceral or other bone metastases, good performance status, being ambulatory before radiotherapy, longer interval between tumor diagnosis and MSCC, and slower development of motor deficits before radiotherapy. Long-course radiotherapy showed a trend. On multivariate analysis, histology, visceral metastases, other bone metastases, ambulatory status before radiotherapy, interval between tumor diagnosis and MSCC, and time of developing motor deficits maintained significance. Conclusion: Poorer local control after radiotherapy for MSCC is associated with visceral metastases and short-course radiotherapy. Long-course radiotherapy seems preferable for patients with more favorable prognoses, given that these patients may live long enough to develop MSCC recurrences. Long-term survival after radiotherapy for MSCC may be predicted if several prognostic factors are considered.