Prognostic factors and a survival score for patients with metastatic spinal cord compression from colorectal cancer

Background: This study aimed to identify independent prognostic factors and to create a survival score for patients with metastatic spinal cord compression (MSCC) from colorectal cancer (CRC). Patients and methods: Data from 121 patients irradiated for MSCC from CRC were retrospectively analyzed. Eleven potential prognostic factors were investigated including tumor type, age, gender, Eastern Cooperative Oncology Group performance status score (ECOG-PS), number of involved vertebrae, ambulatory status prior to radiotherapy (RT), other bone metastases, visceral metastases, interval from cancer diagnosis to RT of MSCC, time of developing motor deficits prior to RT, and the RT schedule. Results: On multivariate analysis, improved motor function was significantly associated with an ECOG-PS of 1-2 (p = 0.011) and a slower development of motor deficits (p < 0.001). Improved local control was significantly associated with absence of visceral metastases (p = 0.043) and longer-course RT (p = 0.008). Improved survival was significantly associated with an ECOG-PS of 1-2 (p < 0.001), ambulatory status (p < 0.001), absence of visceral metastases (p < 0.001), and a slower development of motor deficits (p = 0.047). These four prognostic factors were included in a survival score. The score for each factor was determined by dividing the 6-month survival rate by 10. The prognostic score represented the sum of the factor scores. Four prognostic groups were designed; the 6-month survival rates were 0% for 8-12 points, 26% for 13-18 points, 62% for 20-23 points, and 100% for 24-27 points (p < 0.001). Conclusion: This study identified several independent prognostic factors for treatment outcomes in patients irradiated for MSCC from CRC. The survival prognosis of these patients can be estimated with a new score.