Kara L. Watts

Effects of visceral fat area and other metabolic parameters on stone composition in patients undergoing percutaneous nephrolithotomy

PURPOSE Obesity is a risk factor for metabolic syndrome and urolithiasis, particularly uric acid stones. As estimated by visceral fat area, visceral obesity is a more specific measure of the risk of metabolic syndrome than body mass index. We investigated the effects of visceral fat area and other metabolic factors on uric acid stone formation in patients treated with percutaneous nephrolithotomy. MATERIALS AND METHODS We retrospectively reviewed the records of 269 patients who underwent percutaneous nephrolithotomy. Visceral fat area was measured in each patient on a CT axial slice at the umbilical level using the Aquarius iNtuition fat analysis tool. Analysis was performed to determine the effect of visceral fat area and other comorbidities on uric acid stone formation. RESULTS Of the 269 patients analyzed there was no difference in baseline comorbidities between uric acid and nonuric acid stone formers. Patients with uric acid stones had a significantly higher mean visceral fat area (209.3 vs 161.9 cm², p = 0.001), and rates of hypertension (67.4% vs 47.3%) and coronary artery disease (14.3% vs 4.6%, each p = 0.011). On logistic regression analysis hypertension (OR 2.16, 95% CI 1.05-4.45, p = 0.04) and a high visceral fat area (OR 3.64, 95% CI 1.22-10.85, p = 0.02) were independent risk factors for uric acid stones. CONCLUSIONS As a marker of visceral obesity, visceral fat area contributes to the risk of metabolic syndrome and urolithiasis. Uric acid stone formers showed a significantly higher hypertension rate and mean visceral fat area, which were independent risk factors for uric acid urolithiasis. Evaluating these characteristics in stone formers may facilitate a tailored metabolic assessment and treatment plan.

MP72-15 ROBOTIC PARTIAL NEPHRECTOMY IN PATIENTS WITH CHRONIC KIDNEY DISEASE: OBJECTIVE MEASUREMENT OF SHORT AND LONG TERM RENAL FUNCTIONAL OUTCOMES

METHODS: This multicenter study included 894 patients who had undergone RN between 1994 and 2014. Patients with bilateral renal tumors, metastases, preoperative ESRD, and follow-up <1 year were excluded. The primary endpoint was a >30% eGFR decrease from the postoperative baseline, which was defined as eGFR at 1 month after RN. We identified the preoperative risk factors for a >30% eGFR decrease using the Cox proportional hazard model. A riskstratification model incorporating independent risk factors was then generated. RESULTS: The median age, preoperative eGFR, and postoperative baseline eGFR of the 894 patients (593 men, 301 women) were 65 years, 70.5, and 45.1 ml/min/1.73 m, respectively. Of these, 235, 351, 126, and 131 patients had preoperative CKD defined as eGFR <60 ml/min/1.73 m, hypertension (HT), diabetes mellitus, and cardiovascular disease, respectively. During the median follow-up of 48 months, a >30% eGFR decrease from the postoperative baseline was observed in 47 patients (5.3%). ESRD requiring dialysis developed in 10 of the 47 patients. Multivariate analysis revealed that preoperative CKD and HT were independent risk factors for a >30% eGFR decrease. Five-year >30% eGFR decrease-free survival rates were 98%, 94%, and 84% in patients with 0, 1, and 2 risk factors, respectively (p < 0.001, Figure). Of the 10 patients who developed ESRD, 8 had both risk factors and the remaining 2 had 1 risk factor. CONCLUSIONS: Approximately 5% of patients undergoing RN experienced a >30% eGFR decrease from the postoperative baseline, and one-fifth of these patients eventually developed ESRD. Preoperative CKD and HT were the risk factors for a >30% decline in eGFR.

MP80-18 LOW UTILIZATION OF ADJUVANT THERAPY FOR ADVERSE PATHOLOGIC FEATURES FOLLOWING RADICAL PROSTATECTOMY IN AFRICAN AMERICANS DOES NOT TRANSLATE TO AN INCREASED RISK OF BIOCHEMICAL RECURRENCE

INTRODUCTION AND OBJECTIVES: There is an ongoing debate on removing the label of cancer from Gleason 6 tumors. The aim of the study was to analyze long-term oncological outcomes in patients with pathologic Gleason 3+3 score after radical prostatectomy and to add further knowledge to the discussion. METHODS: We retrospectively analyzed the data of 2942 patients who underwent RP between January 1998 and 2010 and showed a Gleason score 3þ3 in final pathology. Biochemical recurrence (BCR)-free survival, metastasis-free survival (MFS) and cancer-specific survival (CSS) was reported. In multivariate regression analyses further prognosticators of oncological outcome in these patients were analyzed. RESULTS: Median follow-up was 80.7 months. 795 (27.1%) patients underwent lymph node dissection, whereas only one of these patients had positive lymph nodes. Mean preoperative PSA was 6.6 ng/ml, 9.1% of patients had a positive surgical margin and 94.4% had an organ-confined tumor. 198 patients (7.2%) recurred during the follow-up period, 15 (0.5%) patients developed metastasis and 7 (0.2%) patients died of their disease. Patients developing metastases had a significantly higher preoperative PSA (p1⁄40.03) and were more likely to harbor a non-organ-confined tumor (p<0.001). 10-years BCR-free survival, MFS and CSS in patients with Gleason 3+3 was 90.7%, 99.2% and 99.6%, respectively. During follow-up only 1.2% of patients received ADT and 3.7% underwent adjuvant or salvage radiation. In multivariate regression, lymph node status, surgical margin status, preoperative PSA and pT-stage were prognostic factors for BCR. Moreover, lymph node status and pT-stage were significantly associated with occurrence of metastases. CONCLUSIONS: Only 0.5% and 0.2% of the patients with a Gleason 3+3 score in final histology developed metastasis or died of their disease. These data are in favor of removing the label of cancer from Gleason 3+3.