Significance of Pathologic T3a Upstaging in Clinical T1 Renal Masses Undergoing Nephrectomy

We report the results of a single institution investigating the effect of occult pathologic upstaging in patients undergoing nephrectomy, either radical or partial. No patient experienced a recurrence, even with adverse pathologic features, in the short term. Background: The objectives of the present study were to report the incidence of pathologic T3a upstaging in a contemporary cohort of patients with clinical stage T1 (cT1) renal tumors treated with partial or radical nephrectomy; investigate the clinical outcomes; and identify the predictors associated with pathologic upstaging. Materials and Methods: From a single-institution, institutional review board-approved renal tumor database of 945 patients, we identified 610 patients who had undergone surgery for a cT1 renal mass. Data for 494 patients were available for analysis. Of these, 66 lesions had been pathologically upstaged to T3a after surgery and 428 had not. The oncologic follow-up data and clinical and pathologic features were recorded, and multivariable logistic regression analysis was performed to identify the risk factors for pT3a upstaging, controlling for age, gender, body mass index, and nephrectomy type. Results: The cT1 tumors of 66 patients (13.3%) were upstaged to pT3a after surgery. Of these 66 patients, 44 (66.7%) had undergone partial and 22 (33.3%) radical nephrectomy. The median follow-up period was 50 months. No patient with upstaging developed recurrence, and all were disease free at their last follow-up visit. On multivariable analysis, tumor size > 4 cm (odds ratio [OR], 3.766; 95% confidence interval [CI], 1.417-10.011; P < .008), clear cell histologic features (OR, 4.461; 95% CI, 1.498-13.461; P < .007), and positive surgical margins (hazard ratio, 5.118; 95% CI, 2.088-12.547; P < .0001) were associated with upstaging. Conclusion: Of the cT1 lesions in 66 patients, 13% were pathologically upstaged after surgery. The patients with larger tumors, clear cell histologic features, and positive surgical margins were at the greatest risk of upstaging. However, after an intermediate follow-up period, pathologic upstaging did not appear to result in worsened oncologic outcomes.