Prognostic Factors Influencing the Outcome of 267 Consecutive Patients Undergoing Surgery for Metastatic Renal Cell Carcinoma of the Spine: 821

INTRODUCTION: Prognosis of metastatic renal cell carcinoma (RCC) to the spine is generally poor. However, subsets of patients experience a prolonged survival. METHODS: We performed a retrospective analysis of the prognostic factors influencing the outcome of 267 consecutive patients who underwent surgery for RCC metastasis to the spine. Details of age, sex, Fuhrman grade of the original nephrectomy specimen, neurological status, and extent of metastatic disease were collected. Systemic metastasis burden at the time of surgery was classified as: 1) no metastasis; 2) stable (CT scans showed no change in size or number of lesions in two consecutive immediate preoperative series); 3) concurrent (systemic metastasis discovered within 3 months of the spine surgery); and 4) progressing (consecutive preoperative CTs demonstrate increase in size or number of lesions). Kaplan-Meier and Cox regression methods were used to evaluate postsurgical survival in relation to the aforementioned preoperative variables. RESULTS: The overall median survival after spine tumor resection was 11.3 months. Patients with non-progressing metastasis (no metastasis, stable, or concurrent) had a median survival of 20.6 months compared with 5.6 months in patients with progressing metastasis (P < 0.001). Patients who had the spine as the only site of metastasis had a median survival of 19.2 months compared with 9.5 months in patients with additional systemic sites (P < 0.001). Patients with neurological deficits had a worse outcome than those without (5.9 and 13.5 mo, respectively; P < 0.001). Patients with Fuhrman Grade IV had a median survival of 6.1 months compared with 14.3 months for those with Fuhrman Grades I, II, or III (P < 0.001). CONCLUSION: Patients with metastatic RCC confined to the spine have a better outcome than patients with disease in additional systemic sites. Progressing systemic metastasis at the time of spine surgery predicts a very poor survival. Moreover, preoperative neurological deficits and an original nephrectomy specimen graded as IV in the Fuhrman's classification portends worse outcome.