MP59-19 POPULATION-BASED ASSESSMENT OF TREATMENT MODALITIES IN THE ELDERLY WITH LOCALIZED RENAL CELL CARCINOMA: THE 2000–2009 UPDATE

INTRODUCTION AND OBJECTIVES: Treatment management of localized renal cell carcinoma (RCC) has undergone significant changes over time. Our objective was to characterize the treatment patterns of patients diagnosed with localized RCC in a contemporary population-based cohort of the US. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) Medicare-linked database, patients diagnosed with T1 RCC between years 2000 and 2009 were identified. Treatment modalities were defined as nephrectomy, local tumor destruction (LTD), or observation. Surgically-managed patients were further subdivided into radical nephrectomy (RN) and partial nephrectomy (PN). Those who underwent a laparoscopic or robotic-assisted nephrectomy were grouped under the minimally-invasive approach. Finally patient and disease characteristics were evaluated in multivariable logistic regression analyses for prediction of treatment type. All analyses were repeated in patients with T1a RCC. RESULTS: Overall 9350 patients with T1 RCC were identified. Between 2000 and 2009, nephrectomy rates decreased from 88 to 71% (e1.6%/year, P<0.001), LTD rates increased from 0 to 15% (þ1.4%/year, P<0.001), and observation rates remained stable from 13 to 15% (þ0.2%/year, P1⁄40.063). Amongst surgically-managed patients, open RN rates decreased overtime from 86 to 60% (e2.2%/year, P<0.001) while open PN rates increased from 15 to 40% (þ2.5%/year, P<0.001). However, both minimally-invasive RN (from 4 to 37%, þ3.9%/year, P<0.001) and PN rates (from 0 to 19%, þ2.0%/year, P<0.001) increased over time. Similar trends were observed when analyses were restricted to those with T1a RCC only. Notable disparities were noted according to treatment type and gender, socioeconomic status, and race. CONCLUSIONS: During the study span, lower rates of surgical treatment were observed, whereas LTD rates increased over time. In surgically-managed patients, the rates of PN increased significantly. Increases in minimally-invasive RN were also observed.