Postoperative acute kidney injury in patients with papillary renal cell carcinoma as a novel risk factor for local recurrence. Results from a large multicentric, observational study (the record 1 project)

Aim of the study: Aim of the present study was to assess the effect of postoperative acute kidney injury (AKI) on long-term oncologic outcomes after partial nephrectomy (PN) for renal cell carcinoma (RCC). Materials and methods: Overall, 769 consecutive patients undergoing PN for a renal tumor at 19 Italian urological institutions were prospectively collected from January 2009 to December 2012 (RECORd1 Project). Patients were treated with open, laparoscopic or robot-assisted PN as well as simple enucleation or standard PN according to surgeons’ and centres’ preferences. For the current study we extracted data on 594 patients with a histologic diagnosis of RCC and with a minimum 2-year oncologic follow up. Renal function was evaluated as serum creatinine and eGFR using the MDRD (Modification of Diet in Renal Disease) formula at baseline, post- operative day 1, and months 1, 6, 12 and 24 after surgery. Postoperative acute kidney injury (AKI) was defined as an eGFR drop >25% from baseline at first postoperative day. Results: Mean clinical diameter was 3.0 cm (cT1a: 78.5%, cT1b: 18.5%, cT2: 3%), growth pattern was >50% and entirely endophytic in 24.2% and 2.5% of cases respectively. Median preoperative eGFR was 85.8 ml/ minute/1.73 m2. Patients were treated with open, laparoscopic and robotic PN in 49.7%, 33.8%, 16.5% of cases. Hilar clamping was performed in 372 patients (62.6%) with a median warm ischemia time (WIT) of 17 minutes (IQR 13–22). An eGFR decrease >25% (AKI) and >50% from baseline at 1st postoperative day was recorded in 26.3% and 3.2% of cases, while an eGFR drop >25% and >50% from baseline at 24 months from surgery was registered in 16.1% and 1.3% of patients, respectively. ccRCC, pRCC, chRCC, unclassified RCC and others renal tumors were 68.5%, 15.1%, 10.7%, 0.8% and 4.9%, respectively. At a median overall follow-up of 73.9 (52.3–90.6) months, in 52 (8.7%) and 24 (4.0%) patients local and systemic recurrence were recorded, respectively. Patients with pRCC and postoperative AKI had a significantly higher rate of local recurrence compared to those who did not have (61.1% vs 38.9%; p = 0.01). At Kaplan-Meier analysis, the RFS of patients with pRCC was stratified according to surgical approach, hilar clamping, clinical T staging and eGFR drop >25% from baseline [Figure 1–4]. Discussion: In a large contemporary series, at long term follow up the effects of AKI and its determinants seem to be associated with an increased risk of local recurrence after PN. Further studies will be needed to better understand the linkage between AKI, tumor microenvironment and disease recurrence.