Background: The purpose of this study was to evaluate the predictors of positive margins in one of the largest available prospective multi-institutional studies.
Patients and methods: We evaluated all patients who underwent NSS for radiologically diagnosed kidney tumors between January 2009 and December 2012 at 19 urological Italian centers (Registry of Conservative Renal Surgery [RECORd] project). Preoperative and anthropometric data, comorbidities, intraoperative and postoperative outcomes, and histological findings were analyzed. The negative and PSMs were compared according to the clinical and surgical variables. Multivariable logistic regression models were applied to analyze predictors of PSMs.
Results: Eight hundred consecutive patients were evaluated. Seven hundred sixty-one (95.1%) and 39 patients (4.9%) achieved negative and PSMs, respectively. Patients with PSMs were significantly older compared with those with negative margins (median age: 66.6 vs. 61.8 years, respectively; P = .001). A higher incidence of PSMs was observed when NSS was performed for renal masses located in the upper pole (P = .001). A lower rate of PSMs was found in patients treated with simple enucleation rather than standard PN (1.6% vs. 7.4%, respectively; P < .0001). A greater incidence of PSMs was found in Fuhrman 3/4 tumors (11.3%; P < .0001). At multivariable analysis, age (odds ratio [OR], 1.04; P = .01), upper pole tumor location (OR, 2.85; P = .005), standard PN (OR, 3.45; P = .004), and Fuhrman 3-4 nuclear grade (OR, 4.81; P = .001) were found to be independent predictors of PSMs.
Conclusion: In our multi-institutional report, young age, simple enucleation, middle or lower tumor location, and low-grade tumor were demonstrated to be independent predictors of negative SMs.
Keywords: Partial nephrectomy; Positive margin; Predictors; Renal cancer; Simple tumor enucleation.
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