Surveillance Following Nephron-Sparing Surgery: An Assessment of Recurrence Patterns and Surveillance Costs.

Objective To assess the pattern of renal cell carcinoma (RCC) recurrences in nephron-sparing surgery (NSS) patients, and to determine whether current guidelines for surveillance could be modified based on such patterns. Methods Retrospective review of a single-institution NSS database. Pattern of RCC recurrences and factors associated with recurrence were analyzed using univariate and multivariable competing risk regression analyses. Cost of surveillance was estimated based on Medicare charges. Results A total of 505 patients underwent elective NSS for RCC. Pathologic T stage included 394 pT1a and 79 pT1b lesions. Median follow-up was 38.3 (6-88) months. Recurrence was detected in 26 patients (5.1%) at a median of 18.9 months (2.7% pT1a and 12.7% pT1b). The estimated 5-year cumulative incidence of recurrence for unifocal pT1a lesions was 2.7%. On multivariable analysis, stage higher than pT1a (HR, 5.56 [CI. 2.57-12.0]) and the presence of multifocal or bilateral tumors (HR, 3.32 [CI, 1.45-7.61]) were independent predictors of disease recurrence. For the entire cohort, recurrence was observed in only 10 patients beyond 24 months including only 2 cases with pT1a. Conclusion Current guidelines adequately capture most clinically significant recurrences, and with longer follow-up, it may be possible to confirm that routine surveillance beyond 2 years may have little clinical significance for patients with asymptomatic unifocal pT1a.