Editorial Comment from Dr Schwen and Dr Pierorazio to Robot‐assisted partial nephrectomy confers excellent long‐term outcomes for the treatment of complex cystic renal tumors: Median follow up of 58 months

摘要

Between 12% and 17% of renal masses managed with partial nephrectomy have cystic components.1 Abdel Raheem and co-authors have contributed to the current knowledge of surgical management of complex cystic renal masses by providing long-term oncological and functional data after robot-assisted partial nephrectomy (RAPN).2 The retrospective, single-surgeon experience reported no local recurrences, 100% survival and good renal function preservation (88% of estimated glomerular filtration rate) at 58-month follow up. The authors also showed equivalent and favorable perioperative outcomes that resemble other large cohorts of cystic renal masses managed by RAPN.1, 3 Notably, there were no cyst ruptures, no conversions to radical nephrectomy and no positive surgical margins, which are both a credit to the surgeon's experience and the technological advantages afforded by robotic surgery. Based on these encouraging perioperative and long-term outcomes, the authors have concluded that RAPN should be offered as first-line surgical management of cystic renal tumors. Although it might be tempting to draw this conclusion based on favorable outcomes, the data should be interpreted carefully in the context of potential biases. For instance, the rate of malignancy in this series – 85% in Bosniak III lesions and 100% in Bosniak IV lesions – is higher than similar studies in the literature. The Cleveland Clinic's experience with cystic renal masses treated with RAPN cites a malignancy rate of 56% and 75% for Bosniak class III and IV cysts, respectively.3 Reese et al., in a cohort of 133 patients, similarly cites a malignancy rate of 66% and 85%, respectively.4 While the surgeon should be commended for excellent outcomes, there is likely a degree of selection bias not addressed by the methodology of this study. The authors should therefore be commended on impressive perioperative and long-term outcomes for surgical management of cystic renal masses with RAPN. However, growing evidence advocates that active surveillance might be a reasonable treatment option for cystic renal masses due to the indolent behavior and low metastatic potential of these tumors.4 In addition, partial nephrectomy might not be necessary, as some surgeons advocate for incision with ablation or percutaneous ablation of cystic renal masses.5 Tumor biology, rather than surgical approach, is more likely to explain the 100% cancer-specific survival rate at 5-year follow up, which has been mirrored in many cohorts managed by other surgical approaches.6 More research and a growing interest in cystic renal masses are required to best define patients who will benefit from intervention. None declared.