Prognostic Factors for Renal Cell Carcinoma With Bone Metastasis: Who Are the Long-Term Survivors?

Purpose: Renal cell carcinoma is sometimes associated with bone metastasis. Several risk factors have been reported but some are still controversial. Also, the significance of laboratory tests has not been fully examined for such cases.Materials and Methods: We collected data on 94 renal cell carcinoma cases with bone metastasis treated at 3 tertiary referral centers. Clinicopathological parameters and outcome data were analyzed to search for predictors of overall survival retrospectively. The log rank test and the Cox proportional hazard model were used for univariate and multivariate analyses, respectively.Results: There were 64 males with a median age of 63.9 years. Histological diagnosis showed clear cell renal cell carcinoma in 63 patients, nonclear cell renal cell carcinoma in 7 and unclassified cancer in 6. Sarcomatoid differentiation was found in 17 cases. Metastasis was detected synchronously in 37 patients or metachronously at a median interval of 33.1 months. Multivariate analysis identified sa...