PROGNOSTIC FACTORS FOR SURVIVAL AFTER SURGERY OF METASTATIC SPINAL CORD COMPRESSION

Abstract

Background: It is common practice nowadays to treat patients with metastatic epidural spinal cord compression (MESCC) surgically. Extend and type of surgery should be in proper relation to the expected survival time of the patient. It is still difficult to predict patient’s survival time and several scoring systems are evaluated in literature.

Purpose: To evaluate potential prognostic factors for survival after surgery of metastatic spinal cord compression

Material and Methods: In this retrospective study we included all patients who underwent surgery for MESCC in two hospitals in the Netherlands between 2001 and 2007 (n = 56). Medical records were studied for the origin of the primary tumor, the sex, the location of MESCC, the presence of other bone or visceral metastases, the Karnofsky score and the ASA score. Survival data were obtained by computing the time difference between the date of surgery and death. Patients were divided in three groups for the localization of the primary tumor; fast (n=21), moderate (n=19) and slow (n=13) growing tumors. The group of fast growing tumors contains lung cancer, moderate contains renal cancer and slow growing contains breast cancer. Furthermore, groups were made for the location of MESCC and groups were made for the Karnofsky score. Survival times were compared with log-rank tests or cox regression.

Results: The overall median survival after surgery was 7,8 months, with a minimal follow-up time of nineteen months. The difference in survival time between the groups of primary tumors was highly significant (p < 0,001). Patients with fast growing tumors had a much shorter survival time (median 3,5 months) than patients with slow growing tumors (median 60 months), and moderate growing tumors (median 15 months). Patients with visceral metastases had a significant shorter survival time, compared to patients without visceral metastases (p = 0,01). The presence of other bone metastases however, was of no influence, as was the location of MESCC. Patients with a baseline Karnofsky score of 80% or higher had a significant longer survival time than patients with a score of 70% or lower (p=0,022). Sex and ASA score are not significantly associated with survival time.

Conclusion: The type of the primary tumor seems to be strongly associated with survival time. Besides the type of the primary tumor, the presence of visceral metastases and Karnofksy score are predictors for the survival time after surgery as well. Reliable prediction of survival is mandatory, in that way adjustable surgical treatment can be established.