Prognostic factors and a scoring system for survival after radiotherapy for metastases to the spinal column: a review of 544 patients at Shizuoka Cancer Center Hospital

Abstract

Background: To optimize selection of a radiotherapy schedule for patients with spinal metastases, the authors analyzed prognostic factors and developed a scoring system to predict survival in such patients.

Methods: Five-hundred forty-four patients with spinal metastases received radiotherapy at Shizuoka Cancer Center Hospital between September 2002 and November 2006. Prognostic factors for survival were studied using a Cox proportional hazards model, and a scoring system was developed based on regression coefficients: Three points were given for an unfavorable tumor type and bad performance status (> or =3); 2 points were given for hypercalcemia, visceral metastases, and previous chemotherapy; and 1 point was given for multiple bone metastases and age > or =71 years.

Results: The overall survival rates after 6 months, 12 months, and 24 months were 49%, 32%, and 19%, respectively, and the median survival was 5.9 months (95% confidence interval, 4.9-6.8 months). In total, 503 patients (93%) were followed for > or =12 months or until death. These patients were separated into Groups A, B, and C based on scores of 0 to 4, 5 to 9, and 10 to 14, respectively. These groups included 24%, 57%, and 19% of patients, respectively; and the mean median survival for Groups A, B, and C was 27.1 months, 5.4 months, and 1.8 months, respectively. Overall survival rates after 6 months, 12 months, and 24 months were 89%, 77%, and 54% in Group A; 46%, 22%, and 9% in Group B; and 7%, 4%, and 0% in Group C, respectively (P < .001).

Conclusions: The scoring system was able to predict the survival of patients with spinal metastases and may be useful for selecting an optimal radiotherapy schedule.