Daniel Han

MP72-09 TRENDS IN UTILIZATION AND QUALITY OUTCOMES OF PARTIAL NEPHRECTOMY IN CT1B AND CT2A RENAL CELL CARCINOMA: ANALYSIS OF THE NATIONAL CANCER DATABASE

laparoscopic kidney tumor enucleation. The tumor bed parenchyma of 15 mm beyond the pseudocapsule were continuously sectioned and examined to investigate the possible presence of tumor invasion or satellite lesions. RESULTS: The study involved 246 patients, consisting of 148 men (60.2%) and 98 women (39.8%), with a mean age of 60.9 10.3 years. The average tumor size was 5.3 1.7 cm. The histopathologic evaluation revealed that 82.5% of tumors were clear cell RCC, 7.7% were papillary, and 6.5% were chromophobe. The pathological staging showed that 23.2% of tumors were pT1a, 68.3% were pT1b, 3.7% were pT2, and 4.9% were pT3a. On the basis of Fuhrman nuclear grading, 171 lesions (69.5%) were grade 1-2 and 75 (30.5%) were grade 3-4. The incidence of positive surgical margins was 3.3%. For the pathological characteristics of tumor bed, tumor infiltration was detected in 5 cases (2.0%) and satellite lesion was detected in 4 cases (1.6%). In the group of 60 primary tumors 4 cm or less in diameter, 3 (5.0%) were found with residual tumor, 1 with tumor infiltration and 2 with satellite lesion. In the group of 186 primary tumors larger than 4 cm, 6 (3.2%) were found with residual tumor, 4 with tumor infiltration and 2 with satellite lesion. Statistically, there was no significant difference (p1⁄40.809). In the group of grade 1-2, 4 (2.3%) were found with residual tumor, and 5 (6.7%) in the group of grade 3-4 (p1⁄40.195). Median followup was 24 months (range 8-43) with a recurrence rate of 4.1% (10 of 246) and a cancer specific mortality rate of 2.4% (6 of 246). CONCLUSIONS: The risks of tumor infiltration and/or satellite lesions of enucleation tumor bed are relatively low. Tumor enucleation is a histopathologically safe technique for patients undergoing partial nephrectomy.

PD20-07 ONCOLOGIC AND SURVIVAL OUTCOMES FOR PATHOLOGIC T3A UPSTAGING IN CLINICALLY LOCALIZED RENAL MASSES: DOES PARTIAL NEPHRECTOMY INCREASE ONCOLOGICAL RISK?

continuous and categorical variables, respectively. Outcomes of interest includedestimatedblood loss,warm ischemia time, estimatedglomerular filtration rate at 6 months, length of stay, margin status, Fuhrman grade, tumor size, pathological histology, and symptoms index at presentation RESULTS: Among our cohort, 376 (62%) and 228 (38%) patients with were scheduled for RN and PN, respectively. Of the 228 patients originally scheduled for PN, 12% were converted to RN intraoperatively. A smaller proportion of patients scheduled to undergo PN had clear cell/conventional histology (77% vs 88%; p1⁄40.001) on pathology compared to patients scheduled for RN. Among patients with clear cell or papillary histology, a larger proportion of patients scheduled for PN had lower Fuhrman grade (24% vs 10.3% had FG 1 or 2; p<0.0001) on pathology than patients scheduled for RN. Of our 604 patients, 111 patients died, 33 from kidney disease. The median follow up time for survivors was 2.0 years from surgery. On multivariable analysis, scheduled PN was non-significantly associated with better OS (HR 0.62; 95% C.I. 0.37, 1.03; p 1⁄4 0.064), better CSS (HR 0.51; 95% C.I. 0.18, 1.49; p 1⁄4 0.2), and better RFS (HR 0.56; 95% C.I. 0.29, 1.07; p1⁄40.081). From the estimates of the hazard ratio, we suspect that the bias related to surgeons choosing PN or RN based on low or high risk disease is not appropriately adjusted for in our model CONCLUSIONS: We found no evidence to suggest that PN has poorer outcomes than RN in patients with pT3a tumors. The inherent benefits of PN on renal function preservation make this approach very attractive even in larger and complex tumors

MP67-07 PATHOLOGICAL DETERMINANTS OF ONCOLOGIC OUTCOMES IN STAGE II RENAL CELL CARCINOMA: AN INTERNATIONAL MULTICENTER ANALYSIS

bilateral kidneys with single eAML on the left). Only one patient suffered from spontaneous haemorrhage. Two cases developed distant metastasis: one had nodules over bilateral lungs and left anterior mediastinum; the other had recurrence over liver and retroperitoneum one year after surgical intervention. Three cases had venous thrombus (two in renal vein and one in inferior vena cava) and received thrombectomy. All 21 cases received surgical intervention: 13 radical nephrectomy, 7 partial nephrectomy, one was found with retroperitoneal eAML arising from renal capsule thus undergone tumor excision without kidney involvement. The follow up period ranges from 1 to 143 months (average 51 months). Only 2 cases died from unrelated cause. CONCLUSIONS: In our study, the rate of aggressive behavior is 24% (2 distant metastasis and 3 venous invasion in the 21 cases). Some noticeable accompanying characteristics including haemorrhage, coexisting with AML, coexisting with renal cell carcinoma are also seen in this series. The incidence of renal vein and inferior vena cava thrombus formation in our series is high (3 out of 21), therefore, detailed preoperative image evaluation is necessary.

MP72-03 COMPARATIVE ANALYSIS OF RADICAL AND PARTIAL NEPHRECTOMY IN PATIENTS WITH PREOPERATIVE STAGE 2 CHRONIC KIDNEY DISEASE: A MULTICENTER STUDY

Zachary Hamilton*, San Diego, CA; Alessandro Larcher, Milan, Italy; Brian Lane, Grand Rapids, MI; Umberto Capitanio, Milan, Italy; Sumi Dey, Grand Rapids, MI; Aaron Bloch, Charles Field, San Diego, CA; Samer Kirmiz, Grand Rapids, MI; Daniel Han, San Diego, CA; Adam Bezinque, Grand Rapids, MI; Alp Tuna Beksac, San Diego, CA; Cristina Carenzi, Milan, Italy; Fang Wan, James Proudfoot, San Diego, CA; Francesco Montorsi, Milan, Italy; Ithaar Derweesh, San Diego, CA