Renal cell carcinoma (RCC) frequently metastasizes to the spine, and the prognosis can be quite variable. Surgical removal of the tumor with spinal reconstruction has been a mainstay of palliative treatment. The ability to predict prognosis is valuable when determining the role and magnitude of surgical intervention in cancer patients. To better identify factors affecting survival in patients undergoing surgery for spinal metastasis from RCC, the authors undertook a retrospective analysis of a large patient cohort at a tertiary care cancer center.
Relevant clinical data on a consecutive series of patients who had undergone surgery for spinal metastasis of RCC between 1993 and 2007 at The University of Texas MD Anderson Cancer Center were retrospectively reviewed. Demographic data, histopathological grade of primary tumor, timing of spinal surgery relative to diagnosis, treatment history prior to surgery, neurological status, and systemic disease burden were analyzed to determine the impact of these factors on survival outcome.
The authors identified 267 patients who met the study criteria. Five-year overall survival (OS) after spine tumor resection was 7.8%, with a median OS of 11.3 months (95% CI 9.5–13.0 months). Patients with Fuhrman Grade 4 RCC had a median OS of 6.1 months (95% CI 3.5–8.7 months), which was significantly lower than the 14.3 months (95% CI 9.1–19.4 months) observed in patients with Fuhrman Grade 3 or less RCC (p < 0.001). Patients with preoperative neurological deficits had a median survival of 5.9 months (95% CI 4.1–7.7 months), which was significantly lower than the 13.5 months (95% CI 10.4–16.6 months) observed in patients with a normal neurological examination (p < 0.001). Patients whose spine was the only site of metastasis had a median OS of 19 months (95% CI 9.8–28.2 months) after surgery, significantly longer than the 9.7 months (95% CI 8.1–11.3 months) observed in patients with additional extraspinal metastasis sites (p < 0.001). Patients with nonprogressing extraspinal metastasis (no metastasis, stable, or concurrent) had a median survival of 20.6 months (95% CI 15.1–26.1 months), compared with 5.6 months (95% CI 4.4–6.8 months) in patients with progressing metastasis (p < 0.001).
The authors identified several factors influencing survival after spine surgery for metastatic spinal RCC, including grade of the original nephrectomy specimen, activity of the systemic disease, and neurological status at the time of surgery. These clinical features may help to identify patients who may benefit from aggressive surgical intervention.