499 Background: The role of cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) has not been clearly understood after the approval of new targeted therapies, particularly in an elderly population. We therefore conducted this study to evaluate survival difference (CN vs. no CN) among elderly patients with mRCC in targeted era. To limit the heterogeneity in use of targeted agents we define targeted era as February 2006 to December 2011, as sunitinib got FDA approval for use in RCC in January 2006. Methods: We utilized Surveillance, Epidemiology, and End Results (SEER-18) database to identify elderly (≥ 65 years) patients with mRCC, as first primary malignancy, who were diagnosed between February 2006 and 2011. Kaplan-Meier curve and log rank test were used to compare overall survival (OS) and cancer-specific survival (CSS) between patients receiving CN and not receiving CN. Cox proportional hazard model was used for multivariate analysis. Results: Out of 3,365 patients, 1088 (32.3%) received CN. There was a significant survival benefit for those who received CN vs. those who did not (Median OS: 22 months vs. 5 months, p< 0.001; Median CSS: 25 months vs. 6 months, p<0.001). After adjusting for age, sex, race, T-stage, N-stage, histology types, and year of diagnosis, patient receiving CN had significantly better 3-year OS and 3-year CSS compared to patients not receiving CN with HR of 0.37, 95% CI of 0.34 to 0.41; p<0.001 and HR of 0.37, 95% CI of 0.34 to 0.42, p <0.001 respectively. Among patients who received CN, younger age at diagnosis, other races (other than Caucasian and African American), and N0 stage were found to be independent factors predicting better survival. Conclusions: SEER database lacks individual patient’s information. One may argue that the non-surgical group may have larger proportion of patients with poor performance status. Despite this limitation, our study showed that CN has significant survival benefit and should be a serious consideration in elderly patients if they have good performance status.
MP66-06 PROGNOSTIC SIGNIFICANCE OF SARCOMATOID FEATURES IN METASTATIC RENAL CELL CARCINOMA TREATED WITH CYTOREDUCTIVE NEPHRECTOMY AND TARGETED THERAPY
