William Parker

MP34-03 ONCOLOGIC OUTCOMES FOR PATIENTS WITH RESIDUAL CANCER AT CYSTECTOMY FOLLOWING PREOPERATIVE CHEMOTHERAPY: A PATHOLOGIC STAGE-MATCHED COMPARATIVE ANALYSIS

INTRODUCTION AND OBJECTIVES: While neoadjuvant chemotherapy prior to radical cystectomy (RC) has been demonstrated to improve survival compared to RC alone for urothelial carcinoma of the bladder (UCB), the bulk of this survival benefit has been attributed to patients who achieve ypT0 status at RC. The implications of having residual UCB (rUCB) at RC after preoperative chemotherapy (POC) are less clear. As such, we evaluated survival for patients with and without rUCB at RC after POC compared with pathologic stage-matched RC patients who did not receive POC. METHODS: Patients undergoing RC for UCB between 19802010 at Mayo Clinic were identified. All RC pathology was re-reviewed by a single genitourinary pathologist. Patients who received POC for T2-T4 and/or N1-3 M0 UCB were matched 1:2 to patients not exposed to prior chemotherapy based on pT and pN-stage, soft tissue surgical margin status, and year of RC. Kaplan Meier and Cox regression analyses were used to evaluate the associations between POC and cancer-specific (CSS) and overall survival (OS), stratified by presence or absence of rUCB at RC. RESULTS: We matched 111 patients who underwent POC + RC to 222 RC-alone patients. Median age was 68 yrs (IQR 60,74); 59 (18%) were female. Median follow-up was 7.2 yrs (IQR 6,16), during which time a total of 248 patients died, with 148 dying from UCB. In patients without rUCB at RC, there was no difference in 5-yr CSS (86% vs. 90%, p1⁄40.85) or OS (82% vs. 84%, p1⁄40.46) between patients who did versus did not receive POC. Moreover, on multivariable analysis, chemotherapy exposure was not significantly associated with CSS (HR1⁄41.0; 95%CI 0.3-3.1; p1⁄40.9) or OS (HR1⁄40.9; 95%CI 0.4-1.9; p1⁄40.8) in this subgroup. Conversely, among patients with rUCB at RC, receipt of POC was associated with significantly worse 5-yr CSS (32% vs. 56%, p<0.001) and OS (25% vs. 48%, p<0.001). Moreover, on multivariable analysis, chemotherapy exposure remained independently associated with adverse CSS (HR1⁄42.2; 95%CI 1.6-3.1; p<0.001) and OS (HR1⁄42.0; 95%CI 1.5-2.7; p<0.001) among the patients with rUCB. CONCLUSIONS: While patients who achieve a complete response to POC have excellent survival outcomes, patients with residual UCB at RC after POC have a worse prognosis compared to stage-matched RC patients not exposed to chemotherapy. Such patients should be considered for enrollment in novel adjuvant therapy trials, while continued investigation of which patients are most likely to achieve ypT0 status remains warranted.

MP72-12 SURVEILLANCE AFTER SURGERY FOR RENAL CELL CARCINOMA: A RISK-ADAPTED APPROACH

INTRODUCTION AND OBJECTIVES: To evaluate the association between body mass index (BMI) and survival outcomes in patients with non-metastatic RCC. METHODS: A single-institutional retrospective analysis was implemented on 2329 patients who underwent radical or partial nephrectomy for non-metastatic RCC from 2000 to 2014. Enrolled patients were grouped into normal (BMI <23kg/m2, n1⁄4705), overweight (BMI 23-24.9 kg/m2, n1⁄4648), and obese (BMI 1⁄425kg/m2, n1⁄4976) according to BMI cut-offs for Asian population. Outcomes of interest included recurrence free survival (RFS), overall survival (OS), and cancer-specific survival (CSS). Survival curves for each BMI category were estimated and compared using the Kaplan-Meier method with log-rank test. The impact of BMI as continuous or categorical variables on survival outcomes was assessed with multivariable Cox proportional hazard models. RESULTS: Several clinico-pathological factors, including asymptomatic presentation, being female, lower transfusion rate, higher proportion of clear cell histology, and lower frequency of nodal invasion, were observed in association with obese group (all p<0.05). Obese group showed significantly better 5-year RFS (90.7% vs 84.9%, p<0.001), OS (91.8% vs 86.8%, p1⁄40.002), and CSS (94.8% vs 89.4%, p1⁄40.002) rates than normal patients. On multivariable analysis, BMI as continuous variable independently correlated with favorable RFS (hazard ratio [HR] 0.93; 95% confidence interval [CI] 0.89-0.97, p1⁄40.002), OS (HR 0.95; 95% CI 0.91-0.99, p1⁄40.033) and CSS (HR 0.91; 95% CI 0.86-0.97, p1⁄40.002). In addition, multivariable analysis revealed overweight (HR 0.57; 95% CI 0.37-0.87, p1⁄40.009) and obese patients (HR 0.58; 95% CI 0.39-0.87, p1⁄40.009) were associated with significantly reduced risk of RCC related death compared to normal patients. CONCLUSIONS: Our data suggest overweight and obesity defined as increasing BMI are generally related to favorable survival outcomes after nephrectomy for non-metastatic RCC. Further basic researchwill be required to discover the biologicalmechanisms explaining the positive correlation between high BMI and improved RCC survival.

MP15-16 THE ASSOCIATION OF AGE WITH PERIOPERATIVE AND CLINICOPATHOLOGIC OUTCOMES FOLLOWING RADICAL CYSTECTOMY FOR NON-MUSCLE INVASIVE BLADDER CANCER

INTRODUCTION AND OBJECTIVES: Non muscle invasive bladder cancer is a recurrent and progressive disease; currently we are unable to forecast recurrence in the individual patient. Recently we developed a mathematical model that found NLR as a good prognostic tool. The model was tested retrospectively in an additional study and found accurate too. The aim of the current study is to assess its accuracy to forecast recurrence prospectively in patients with NMIBC METHODS: All patients admitted to bladder tumor resection (TURBT) and agreed to participate in the study had blood drawn for blood count 24 hours prior to surgery. Patients with non-muscle invasive tumor were recruited and prospectively followed. Patients had urine cytology and cystoscopy every 3 months for 2 years following resection. Time to recurrence and recurrence free of tumor were recorded. Statistical analysis was done with X2 test for categorical parameters and T test for serial parameters. Logistic regression was performed to forecast prognosis. RESULTS: 123 patients were recruited, mean age was 71 years, all patients had at least 1 year follow up. Twenty nine patients (23.6%) experienced biopsy proven tumor recurrence. The mean time for recurrence was 7.38 months.Neutrophil to Lymphocyte rate > 2 showed direct statistically significant correlation with tumor recurrence (p1⁄40.038), tumor stage showed the same correlation (p1⁄40.048). The specificity of our recurrence forecasting model was 96.8%. EORTC score did not demonstrate significance between the recurrent and nonrecurrent groups. CONCLUSIONS: Our mathematical model that found NLR as a prognostic tool in patients with NMIBC was tested for the first time prospectively. The model demonstrated its ability to forecast recurrence more accurately then tumor stage grade and EORT score in the individual patient with NMIBC.The main limitation of this work is the relatively low number of patients.

MP72-01 PREDICTING RENAL CELL CARCINOMA PROGRESSION AFTER SURGERY

INTRODUCTION AND OBJECTIVES: Multiple algorithms exist for the prediction of progression after surgical treatment of localized renal cell carcinoma (RCC); however, most are limited to clear cell (ccRCC) only, and have not been updated with contemporary pathologic assessment. We therefore sought to develop predictive models for progression in ccRCC, papillary RCC (papRCC), and chromophobe RCC (chrRCC). METHODS: Binephric patients treated with radical or partial nephrectomy for sporadic, unilateral M0 ccRCC, papRCC, or chrRCC between 1980 and 2010 were identified. All patients had their pathology slides re-reviewed by one pathologist, blinded to patient outcome. Associations with time to progression (defined as local recurrence, distant metastasis, or death from RCC) were evaluated with multivariable Cox proportional hazards regression with stepwise selection using a 500sample bootstrap resampling approach. RESULTS: In total, 3,549 patients were identified: 2,726 (76.8%) with ccRCC, 601 (16.9%) with papRCC, and 222 (6.3%) with chrRCC. For patients with ccRCC, median follow-up was 9.9 years during which time 862 progressed. Features independently associated with ccRCC progression were constitutional symptoms, grade, coagulative necrosis, sarcomatoid differentiation, tumor size, fat invasion, tumor thrombus level, extension beyond Gerota’s fascia, and pN classification. The c-index of this model was 0.83. For papRCC patients, median follow-up was 10.3 years during which time 66 had progressed. Features associated with papRCC progression were grade, fat invasion, and tumor thrombus level, resulting in a c-index of 0.77. For chrRCC patients, median follow-up was 9.1 years during which time 35 had progressed. Features associated with progression included sarcomatoid differentiation, fat invasion, and pN classification, resulting in a c-index of 0.77. Predicted 10-year progression-free survivals for patients without any risk factors were 96%, 96%, and 91% for ccRCC, papRCC, and chrRCC, respectively. CONCLUSIONS: Using routine clinical and pathologic data, we generated 3 histology-specific predictive models for progression after surgical management of RCC. These models have excellent discrimination and may prove important in patient counseling and follow-up planning after surgical intervention. Source of Funding: None

MP100-06 CRYOABLATION OF CT1 RENAL MASSES IN “HEALTHIER” PATIENTS: EARLY OUTCOMES FROM MAYO CLINIC

INTRODUCTION AND OBJECTIVES: Current guidelines suggest that percutaneous thermal ablation (PTA) can be utilized in those with significant comorbidity who are unable to tolerate surgery (radical or partial nephrectomy). However, the use of PTA in “healthier” patients, who are otherwise candidates for surgery, has been limited. Here, we reviewed our institutional experience in such patients electing to undergo PTA, specifically cryoablation. METHODS: We identified patients 65 years undergoing percutaneous cryoablation for solitary, non-metastatic renal masses <7cm (cT1). We further limited our cohort to patients with an ASA score of 1 or 2, and in whom pre-operative eGFR was >60. Clincopathologic characteristics and recurrence patterns (local recurrence within the kidney versus metastatic disease) were evaluated. RESULTS: Between March 2003 and December 2015, 705 patients underwent cryoablation, of whom 43 (6.1%) met inclusion criteria. Median age of this cohort was 57 years (IQR 52-62), with preablation eGFR of 75.6 (IQR 69.0-86.3) (Table). 14 (32.6%), 19 (44.2%), and 10 (23.2%) patients reported zero, one, or multiple prior abdominalpelvic surgeries, respectively. Five patients (11.6%) had a prior partial nephrectomy. The majority (40, 93.0%) of ablated masses were cT1a, with 3 (7.0%) being cT1b. Median tumor size was 2.0 cm. 27 masses (63.7%) were biopsy-proven renal cell carcinoma (RCC) and 6 (13.6%) were benign; histology was unknown in 10 (22.7%). Follow-up imaging was available for 37 patients. Median radiological follow-up was 22 months (IQR 9-42), during which time 2 patients developed metastatic disease and and 1 developed local recurrence; all events were in patients with biopsy-proven RCC. No patients died from RCC during this time period. CONCLUSIONS: In this single institution cohort of “healthier” patients with cT1 solitary renal masses, cryoablation offered reasonable short term oncologic control. While longer follow-up data are needed to evaluate for durability, cryoablation in healthier patients, particularly those with challenging surgical anatomy or prior renal surgery, warrants further study.