IMPACT OF GENDER IN NEPHRON-SPARING SURGERY: COMPARISON OF PERIOPERATIVE AND PATHOLOGICAL OUTCOMES FROM THE DEFINITIVE RESULTS OF RECORD1 PROJECT

Aim: The aim of this study was to analyze gender differences in terms of perioperative and pathological features in a multicentre Italian dataset of patients (RECORd Project) undergoing nephron-sparing surgery (NSS). Materials and Methods: Overall, 1,055 patients treated with NSS, between January 2009 and December 2012, were evaluated. An evaluation of gender differences of pre-, intra- and postoperative, as well as pathological variables was performed. Results: Overall, 630 males and 346 females were analyzed. No significant difference was found between males and females in age at operation (analyzed as continuous and nominal (<75 years and ≥75 years) variable), ECOG score, clinical symptoms at diagnosis, tumor side, tumor growth pattern and localization and, also, number of lesions at radiological evaluation. A significant difference was found between males and females in body mass index (BMI) (26.3 (24.7-28.4) vs. 25.3 (22.5-27.5). p<0.001), surgical indication (relative 14.9% vs. 11.9%; absolute 8.8% vs. 3.2%, respectively; p=0.001), pre-operative hemoglobin (14.5±1.3 vs. 13.3±1.1, p<0.001) and creatinine (1.0±0.5 vs. 0.8±0.2, p<0.001). In intra-operative variables, no significant difference was found between the two groups regarding surgical approach (open vs. minimally invasive), technique (standard partial nephrectomy vs. simple enucleation), pedicle clamping and ischemia time. A significant difference was found between males and females in operative time (200 (100-300) vs. 150 (100-250) min, respectively, p=0.03) and estimated blood loss (EBL) (135 (105-180) vs. 125 (105-160) cc, respectively, p=0.01). A slight difference between the two groups was found in intraoperative complication (5.8% vs. 3.2%, respectively, p=0.07). No difference between the two groups was found regarding overall medical, overall surgical, surgical Clavien 2 and 3 complications. A significant difference was found between the two groups in preoperative-1st and preoperative-3rd day delta estimated glomerular filtration rate (eGFR) (10.1 (0.0-23.0) vs. 12.7 (0.0-30.2), respectively, p=0.01 and 8.5 (0.0-23.0) vs. 18.9 (0.0-30.2), respectively, p=0.01). Regarding pathological data, a significant difference was found between males and females relating to malignant/benign histotype (84.1%/15.9% vs. 71.4%/28.6%, respectively, p=0.001). Males present a 58.3% of clear cells renal cell carcinoma (RCC) vs. 54.6% of females with a slightly higher 3rd-4th Fuhrman grade (19.6% vs. 15.0%, respectively, p=0.15). Conclusion: NSS in males presented a higher intra-operative difficulty in terms of time, bleeding and complications. Females present a higher rate of benign tumors, as described in literature. Males present a slightly higher clear cell RCC rate with higher Fuhrman grade.