Alexa Meyer

Predicting Renal Parenchymal Loss after Nephron Sparing Surgery.

PURPOSE We analyze the relationship among various patient, operative and tumor characteristics to determine which factors correlate with renal parenchymal volume loss after nephron sparing surgery using a novel 3-dimensional volume assessment. MATERIALS AND METHODS We conducted a retrospective review of an institutional database of patients who underwent nephron sparing surgery from 1992 to 2014 for a localized renal mass. Tumors were classified according to the R.E.N.A.L. nephrometry system. Using 3-dimensional reconstruction imaging software, preoperative and postoperative renal parenchymal volume was calculated for the ipsilateral and contralateral kidney. RESULTS A total of 158 patients were analyzed. Mean patient age was 58.7 years and mean followup was 40.1 months. Mean preoperative tumor volume was 34.0 cc and mean tumor dimension was 3.4 cm. Mean R.E.N.A.L. nephrometry score was 6.2, with 60.1%, 34.2% and 5.7% of tumors classified as low, medium and high complexity, respectively. Mean change in renal parenchymal volume after nephron sparing surgery was -15.3% for the ipsilateral kidney and -6.8% for total kidney volume. On univariate analysis ischemia time, tumor size, R.E.N.A.L. nephrometry score, complexity grouping and the individual nephrometry components of tumor size, percent exophytic, anterior/posterior, depth and tumor proximity to the renal artery or vein were associated with greater renal parenchymal volume loss. On multivariate analysis only ischemia time, tumor size, posterior location and percent exophytic were independently associated with more renal parenchymal volume loss. CONCLUSIONS Using precise 3-dimensional volumetric analysis we found that ischemia time, tumor size and endophytic/exophytic properties of a localized renal mass are the most important determinants of renal parenchymal volume loss.

MP72-09 ADJUVANT CISPLATIN LEADS TO A LARGER DECLINE IN GFR THAN NEOADJUVANT CISPLATIN IN RADICAL CYSTECTOMY PATIENTS

RESULTS: No significant difference was noted in 5-year CSS between GC NAC (58%) and non-NAC cohorts (61%). The median followup was 19.6 months for GC NAC and 106.5 months for non-NAC. Patients with residual non-muscle-invasive disease (pTis, pTa, pT1) after GC NAC exhibit similar 5-year CSS relative to patients with no residual carcinoma (pT0), p1⁄40.99. NAC pathologic responders ( T1, n1⁄480) demonstrated improved 5-year CSS rates of 90.6% vs. 27.1% (p<0.01) and decreased nodal positivity rates of 0% vs. 41.3% (p<0.01) compared to NAC pathologic non-responders ( pT2). Clinical and pathologic outcomes were inferior in NAC pathologic non-responders compared to the entire RC only treated cohort (pT2-T4). A significantly lower pathologic non-response rate was seen in those able to tolerate sufficient dosing of NAC when patients were stratified by the JHH-DI (p1⁄40.049) which is congruent with NCCN guidelines. A multivariate decision tree model demonstrated age 60 years and clinical stage cT2 as significant of response to NAC (p<0.05). CONCLUSIONS: Pathologic non-responders fare worse than patients proceeding directly to RC alone, suggesting the need to identify clinical features predictive of poor response prior to the initiation of chemotherapy. To this effect, multiple predictive models incorporating clinical, histopathologic, and molecular features are currently being developed to identify patients, prior to the initiation of therapy, that are most likely to benefit or not benefit from GC NAC.