Commentary on "effective testicular germ cell tumor therapy on renal function." Cost NG, Adibi M, Lubahn JD et al, Department of Urology, University of Texas Southwestern Medical School, Dallas, TX: Urology 2012;80:641.

Objective: To assess the pre- and post-therapy glomerular filtration rate in patients with testicular germ cell tumors to determine its effect on the natural history of renal function.

Methods: We reviewed an institutional database of patients with testicular germ cell tumor, with pre- and post-therapy serum creatinine levels available. The renal function was estimated using a calculated glomerular filtration rate. We compared the patients treated without chemotherapy (orchiectomy with or without radiotherapy or retroperitoneal lymph node dissection) with those who received systemic chemotherapy. We analyzed the data for the outcome of new-onset chronic kidney disease (CKD) stage 3 between these groups. Kaplan-Meier curves were constructed and compared using a log-rank test.

Results: A total of 144 patients were reviewed. The testicular germ cell tumor stage distribution was stage I in 78 (54.2%), stage II in 28 (19.4%), and stage III in 38 (26.4%). Overall, the median creatinine and estimated glomerular filtration rate at diagnosis was 0.9mg/dL (range 0.5-1.5) and 104.0mL/min/1.73m(2) (range 58.7-235), respectively. Of the 144 patients, 102 (70.8%) had CKD stage 0-1, 41 (28.5%) stage 2, and 1 (0.7%) stage 3. The median creatinine and estimated glomerular filtration rate at the last follow-up visit was 1.0mg/dL (range 0.6-2.6) and 95.5mL/min/1.73m(2) (range 31.5-167.6), respectively. This difference between the pre- and post-therapy estimated glomerular filtration rate was significant (P<0.01). A total of 81 patients (56.3%) received chemotherapy (median 4 cycles, range 1-12), and 63 (43.7%) were treated without chemotherapy. Of the 81 patients who received chemotherapy, 8 (9.9%) developed new-onset CKD 3 compared with none in the nonchemotherapy group (P =0.01).

Conclusion: Patients with testicular germ cell tumor receiving chemotherapy experienced a significant decrease in the estimated glomerular filtration rate and had a significantly increased risk of developing CKD stage 3 compared with those treated without chemotherapy. These findings offer insight into the long-term risks of testicular germ cell tumor survivorship and will be useful in counseling patients.