Stella Kang MD, Abstract Co-Author: Nothing to Disclose

Pari Pandharipande MD, MPH, Presenter: Nothing to Disclose

The current standard of care for small renal masses is partial nephrectomy (PN), but concern has been raised over consequent renal functional decline. In patients with chronic kidney disease (CKD), we compared life expectancy (LE) after PN to that after a treatment strategy in which patients were triaged to percutaneous ablation vs. PN based on renal function and Nephrometry Score (NS), a tumor anatomy scoring system.

We developed a decision-analytic Markov model to project LE in hypothetical patients with mild or moderate CKD undergoing treatment of small renal masses. Our model incorporated NS, which correlated with tumor anatomy predictive of post-surgical renal functional loss. Tested strategies were: 1) nonselective PN; and 2) selective PN, with triage to percutaneous ablation for moderate CKD and any NS, or for mild CKD and high NS, and otherwise PN. The model accounted for benign and malignant lesions, renal functional decline after each treatment type, mortality rates by CKD stage, Charlson comorbidity index, tumor NS distribution, and local recurrence and metastatic disease rates for each treatment. Patients were susceptible to all-cause mortality, surgical mortality, and cancer-specific mortality. Our primary model outcome was LE. We used sensitivity analysis to determine the stability of results when varying key parameters.

Nonselective treatment with PN of 65-year-old men (mean age of renal cell cancer diagnosis) resulted in an average decrease in LE of 0.46 years (11.0 to 10.54 years) relative to selective PN, due to worsening CKD and associated cardiovascular mortality. 65-year-old women experienced an average LE loss of 0.56 years (12.7 to 12.14 years). Among all parameters, model results were most sensitive to variability in the rate of renal function decline and CKD-related mortality.

Renal mass ablation is likely to be the most effective strategy for treatment of small renal masses in patients with baseline moderate CKD, or with mild CKD and complex tumor anatomy.

Renal mass ablation may be a more effective treatment option for small renal masses than partial nephrectomy in patients with moderate CKD or with mild CKD and complex tumor anatomy.

Kang, S, Pandharipande, P, Patient-Centered Treatment Selection for Small Renal Masses Using Nephrometry Score and Renal Function: A Comparative Effectiveness Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016054.html