Background: A retrospective study was performed to examine the outcome of patients with colorectal cancer who had metastatic spinal cord compression (MSCC) and received radiation therapy (RT).
Methods: Forty episodes of MSCC were treated with external beam RT in 34 patients with metastatic colorectal cancer. The median total dose was 3000 cGy (1800-4750 cGy), and the daily fraction size was 300 cGy (151-400 cGy). All patients were followed until death.
Results: Median overall survival for the entire cohort was 4.1 months. Of 21 patients ambulatory before RT, 20 remained ambulatory after treatment, whereas only 2 of 9 patients who were nonambulatory regained full ambulatory status. Patients with rectal primary tumors had improved survival (median 7.9 months) compared with those who had colon primary tumors (2.7 months) (P = 0.002). Patients who received a total dose of more than 3000 cGy had a better survival (7 months) than those who received 3000 cGy or less (3.1 months) (P = 0.024). There was a trend for improved survival in patients fully ambulatory at diagnosis (P = 0.056) and after RT (P = 0.07). Unlike other primary sites in which approximately 70% of lesions are located in the thoracic spine, the location of epidural metastasis in colorectal primary tumors was most frequently in the lumbar spine (55% of lesions).
Conclusions: Prognostic features and outcomes for MSCC with primary colorectal cancer are similar to those for other primary sites. There is a suggestion that rectal primary tumors may be associated with an improved outcome compared with colon primary tumors. Patients who received more than 3000 cGy total dose had a longer survival than those who received lower total doses.