Tumor Anatomy Scoring and Renal Function for Nephron-Sparing Treatment Selection in Patients With Small Renal Masses: A Microsimulation-Based Decision Analysis.
OBJECTIVE
The purpose of this article is to compare the effectiveness of a treatment algorithm for small renal tumors incorporating the nephrometry score, a renal tumor anatomy scoring system developed by urologists, with the current standard of uniformly recommended partial nephrectomy in patients with mild-to-moderate chronic kidney disease (CKD).


METHODS
We developed a state-transition microsimulation model to project life expectancy (LE) in hypothetic patients with baseline mild or moderate CKD undergoing treatment of small renal masses. Our model incorporated the nephrometry score, which is predictive of postsurgical renal function loss. The two tested strategies were uniform treatment with partial nephrectomy and selective treatment based on nephrometry score and CKD stage, including percutaneous ablation for CKD stages 2 or 3a and intermediate-to-high nephrometry score or stage 3b CKD and any nephrometry score; otherwise, partial nephrectomy was assumed for other CKD stages and nephrometry scores. The model accounted for benign and malignant lesions, renal function decline, recurrence, and metastatic disease rates specific to each treatment, mortality by CKD stage, and comorbidities. Sensitivity analysis tested the stability of results when varying key parameters.


RESULTS
Selective treatment with partial nephrectomy resulted in an average LE benefit of 0.48 year (95% interpercentile range, 0.42-0.54 year) in 65-year-old men and 0.37 year (95% interpercentile range, 0.30-0.43 year) in 65-year-old women relative to nondiscriminatory surgery, due to worsening CKD and cardiovascular mortality associated with partial nephrectomy. Model results were most sensitive to the rate of renal function decline and CKD-related mortality.


CONCLUSIONS
Nephron-sparing treatment selection for small renal masses based on nephrometry score may improve LE in patients with mild or moderate CKD.
1 Department of Radiology, NYU School of Medicine, 550 First Ave, New York, NY 10016.|2 Department of Population Health, NYU School of Medicine, New York, NY.
Stella K
SK
Kang
3 Department of Urology, NYU School of Medicine, New York, NY.
William C
WC
Huang
4 Department of Medicine, Division of Nephrology, NYU School of Medicine, New York, NY.
Edward Y
EY
Skolnik
5 Department of Radiology, Massachusetts General Hospital, Boston, MA.
Debra A
DA
Gervais
2 Department of Population Health, NYU School of Medicine, New York, NY.|6 Department of Medicine, NYU Medical Center, New York, NY.
R Scott
RS
Braithwaite
5 Department of Radiology, Massachusetts General Hospital, Boston, MA.|7 Institute for Technology Assessment, Massachusetts General Hospital, Boston, MA.
Pari V
PV
Pandharipande
D000368:Aged; D000465:Algorithms; D015897:Comorbidity; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007677:Kidney Function Tests; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008017:Life Expectancy; D008297:Male; D009392:Nephrectomy / Q000379:methods*; D018579:Patient Selection; D011237:Predictive Value of Tests; D015996:Survival Rate; D016896:Treatment Outcome
chronic kidney disease; nephrometry score; partial nephrectomy; renal mass