This study was designed to assess the risk of short and long-term renal function deterioration in patients harboring tumor thrombus, who usually necessitate more extensive and complex surgeries, such as inferior vena cava clamping. Furthermore, these patients face higher odds of intraoperative bleeding. As a consequence, we hypothesized that undergoing radical surgery may adversely impact the contralateral kidney too, resulting in poorer functional outcomes compared to cases without tumor thrombus.
Notably, previous research lacked comprehensive long-term postoperative renal function data, a gap that our study aimed to fill.
Our findings indicate a 20% decrease in eGFR immediately after surgery, in contrast with a roughly 8% decline in patients undergoing standard radical nephrectomy. This percentage decrease remained stable at 60 months for patients with tumor thrombus (around 25%), while patients who underwent standard nephrectomy reached around 15% decrease at the same time-point.
This eGFR decline is associated with an increased incidence of acute kidney injury after surgery, which is a predictor of long-term renal impairment, and heightened blood loss. Of note, patients with or without tumor thrombus initially presented with comparable preoperative eGFR levels.
In this context, the extent of thrombus extension emerges as a pivotal factor. We observed that thrombi extending above the diaphragm significantly elevate the risk of acute kidney injury, likely due to the complexity of surgery and the associated hemodynamic instability, leading to increased blood loss and surgical time.
Consistent with prior research, patients with tumor thrombus exhibited worse oncological outcomes, such as lower disease-free and cancer-specific survival rates compared to their counterparts. Tumor thrombus extension also correlates with poorer oncologic outcomes.
Given these findings, tumor thrombus emerges as a significant negative prognostic factor impacting both oncological and functional outcomes. Consequently, these patients may need a preoperative multidisciplinary approach involving oncologists, nephrologists, and nutritionists, recognizing the multifaceted challenges they may encounter.
While our study offers valuable insights, we acknowledge its limitations stemming from its retrospective design, potentially introducing selection bias. Moreover, the impact of adjuvant treatments on functional and survival outcomes remains unexplored. Thus, future studies should prioritize prospectively collected, detailed data to yield more impactful evidence.
Written by:
- Pietro Scilipoti, MD, Urologist, Department of Urology and Division of Experimental Oncology, Urological Research Institute, IRCCS San Raffaele Scientific Institute, San Raffaele Hospital, Milan, Italy
- Giuseppe Rosiello, MD, Urologist, Department of Urology and Division of Experimental Oncology, Urological Research Institute, IRCCS San Raffaele Scientific Institute,San Raffaele Hospital, Milan, Italy