When comparing patients with acquired vs. congenital SK, we found that congenital SK patients tended to have a larger reduction in renal function at 12 months post-op compared to acquired SK patients, however, only 3 patients were in the congenital SK group. This raises the question of how renal function changes over a longer period in congenital vs. acquired SK patients. Prior work found that children with congenital SK tended to have a higher level of GFR preservation compared to adults with acquired SK,3 which could suggest that congenital SK patients have a rebound in renal function over a longer follow up time.
The overall survival data from our study highlights a significant impact of comorbidities on mortality rates among patients. A study by Horsbøl et al. demonstrated that patients with RCC and Charlson Comorbidity Index (CCI) scores ≥3 had higher mortality rates than those who had lower CCI scores, reflecting the cumulative burden of comorbidities on mortality outcomes.4 Notably, all deceased patients in our cohort had CCI scores ≥ 5. This underscores the severe burden of comorbidities and their effects on patients with RCC and offers a possible explanation for the relatively high mortality rate in our cohort.
One future direction of this work is to compare treatment types for managing SK patients with RCC. For instance, work by Attawettayanon et al. assessed outcomes in SK patients treated with thermal ablation vs. partial nephrectomy and found that patients treated with thermal ablation tended to have better functional outcomes but also had higher local RCC recurrence rates.5 Future work can conduct a more comprehensive comparison of different ablative therapies (MWA, thermal ablation, and cryoablation) and partial nephrectomy to better understand the benefits and risks of each option and to optimize treatment for SK patients with RCC.
Written by: Carlos Justo-Jaume, Max Stempel, Jessica Qiu, Luis Gonzalez Miranda, Guofen Yan, Genevieve Lyons, Kenneth Sands, Noah Schenkman, Tracey Krupski, Stephen Culp, Jennifer Lobo
University of Virginia, Charlottesville, USA.
References:
- Justo-Jaume C, Stempel M, Qiu J, et al. Efficacy and safety of microwave ablation in solitary kidney patients with T1a small renal masses. Abdom Radiol N Y. Published online January 7, 2025. doi:10.1007/s00261-024-04779-7
- Xiaobing W, Wentao G, Guangxiang L, et al. Comparison of radiofrequency ablation and partial nephrectomy for tumor in a solitary kidney. BMC Urol. 2017;17:79. doi:10.1186/s12894-017-0269-4
- McArdle Z, Schreuder MF, Moritz KM, Denton KM, Singh RR. Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney. Front Physiol. 2020;11. doi:10.3389/fphys.2020.00725
- Horsbøl TA, Dalton SO, Christensen J, et al. Impact of comorbidity on renal cell carcinoma prognosis: a nationwide cohort study. Acta Oncol. 2022;61(1):58-63. doi:10.1080/0284186X.2021.2005255
- Attawettayanon W, Kazama A, Yasuda Y, et al. Thermal Ablation Versus Partial Nephrectomy for cT1 Renal Mass in a Solitary Kidney: A Matched Cohort Comparative Analysis. Ann Surg Oncol. 2024;31(3):2133-2143. doi:10.1245/s10434-023-14646-2