Validation and simplification of a score predicting survival in patients irradiated for metastatic spinal cord compression

BACKGROUND: Based on an analysis of 1852 retrospectively evaluated patients with metastatic spinal cord compression (MSCC), a scoring system was developed to predict survival. This study was performed to validate the scoring system in a new data set. METHODS: The score included 6 prognostic factors: tumor type, interval between tumor diagnosis and MSCC, other bone or visceral metastases, ambulatory status, and duration of motor deficits. Scores ranged between 20 and 45 points, and patients were initially divided into 5 groups: those with 20 to 25 points, those with 26 to 30 points, those with 31 to 35 points, those with 36 to 40 points, and those with 41 to 45 points. To facilitate the clinical use of the score, the patients were regrouped into 3 groups: those with 20 to 30 points, those with 31 to 35 points, and those with 36 to 45 points. In this study, data of 439 new patients were included who were divided into the same prognostic groups as in the preceding study. RESULTS: In this study, the 6-month survival rates were 7% (for those with 20-25 points), 19% (for those with 26-30 points), 56% (for those with 31-35 points), 73% (for those with 36-40 points), and 90% (for those with 41-45 points), respectively (P<.0001). After regrouping, the 6-month survival rates were 14% (for those with 20-30 points), 56% (for those with 31-35 points), and 80% (for those with 36-45 points), respectively, in this study (P<.0001). CONCLUSIONS: In the current study, the difference in 6-month survival between the prognostic groups was found to be as significant as in the preceding study. Thus, this scoring system was considered valid to estimate survival of MSCC patients. The system could have been simplified by including only 3 instead of 5 prognostic groups.