[Functional and oncologic outcomes of partial nephrectomy for cystic renal cell carcinoma: A single-center retrospective study].

Objective: To investigate the postoperative renal function and oncologic outcomes of cystic renal cell carcinoma with partial nephrectomy, and to compared the single-center data on surgical outcomes with the Surveillance, Epidemiology, and End Results (SEER) database.

Methods: This was a retrospective study that included the patients with cystic renal cell carcinoma who underwent partial nephrectomy in the Department of Urology, Peking University Third Hospital (PUTH) from 2010 to 2023. The clinical data and depicting baseline characteristics were collected. Renal dynamic imaging and the Chinese Coefficients for Chronic Kidney Disease Epidemiology Collaboration (C-CKD-EPI) formulae were used to calculate the estimated glomerular filtration rate (eGFR). The renal function curves over time were then plotted, and the patients were followed-up to record their survival status. Cases of cystic renal cell carcinoma in the SEER database between 2000 and 2020 were included, propensity score matching (PSM) was performed to balance the differences between SEER cohort and PUTH cohort, and the cancer-specific survival (CSS) curves for both groups were plotted and statistical differences were calculated by the Kaplan-Meier method.

Results: A total of 38 and 385 patients were included in the PUTH cohort and SEER cohort, respectively, and 31 and 72 patients were screened in each cohort after PSM. Of the baseline characteristics, only tumor size (P=0.042) was found to differ statistically between the two groups. There was no statistically significant difference between the two cohorts in terms of CSS after PSM (P=0.556). The median follow-up time in the SEER cohort was 112.5 (65, 152) months and a 10-year survival rate of 97.2%, while the PUTH cohort had a median follow-up of 57.0 (20, 1 172) months and a 10-year survival rate of 100.0%. There was no statistically significant difference between eGFR determined by preoperative renal dynamic imaging and the results of the C-CKD-EPI formulae based on creatinine estimation (P=0.073). There was a statistically significant difference in eGFR among the preoperative, short-term postoperative, and long-term postoperative (P < 0.001), which was characterized by the presence of a decline in renal function in the short-term postoperative period and the recovery of renal function in the long-term period.

Conclusion: Partial nephrectomy for cystic renal cell carcinoma is safe and feasible with favorable renal function and oncologic outcomes.