Introduction: The AUA guidelines for clinically localized renal neoplasms were updated in April 2013 with risk-adjusted recommendations for follow up after partial nephrectomy, allowing less frequent surveillance imaging in low risk patients. Our institution then switched from a physician preference, non-standardized practice to strict guidelines adherence. We sought to evaluate the impact of this practice change on patient outcomes.
Methods: We identified 3320 patients who underwent PN between January 2000 and March 2017. Patients with missing pathologic or incomplete staging data were excluded, leaving 3261 patients for analysis. We used the Kaplan-Meier method to estimate MFS, CSS, and OS and a multivariable Cox proportional hazard regression for each outcome, with whether patients were followed up after guideline implementation as the predictor, adjusted for dichotomized risk (low: tumor stage on pathology pT2) and tumor size on pathology. All statistical analyses were conducted using STATA 15.0 (StataCorp, College Station, TX).
Results: The “Before 2013” cohort of 2295 patients and “After 2013” cohort of 966 patients had similar overall characteristics, with the majority of tumors stage pT1 in both groups (79% and 80%, respectively). Average tumor size was 2.9cm in both groups, with positive surgical margin rates of 5.8% and 5.1% in before and after cohorts. Two hundred and ninety-seven patients died from any cause, 33 of whom died from their kidney disease. A total of 46 patients had biopsy proven metastases over the study period. Patients in the group followed after guidelines implantation had better MFS (HR: 0.27; 95% CI 0.11, 0.68; p =0.006), with a median follow up time among survivors of 4.5 (IQR 2.0, 7.7) years. The guidelines group also had better CSS (HR: 0.20; 95% CI 0.05, 0.86; p = 0.030) and non-significantly better OS (HR: 0.68; 95% CI 0.45, 1.02; p = 0.060).
Conclusions: Detection of metastatic recurrence following partial nephrectomy is a rare event, regardless of follow up regimen. Although detection of metastases appeared to be less following our institution’s formal adoption of the AUA guidelines, it did not adversely impact patient survival. Source of
Funding: This research was supported by the Sidney Kimmel Center for Prostate and Urologic Cancers and funded in part through the NIH/NCI Cancer Center Support Grant P30 CA008748.