Perioperative morbidity, oncological outcomes and predictors of pT3a upstaging for patients undergoing partial nephrectomy for cT1 tumors.

Objectives: To evaluate perioperative morbidity, oncological outcome and predictors of pT3a upstaging after partial nephrectomy (PN).

Materials And Methods: Retrospective study of 1042 patients who underwent PN for cT1N0M0 renal cell carcinoma between 2007 and 2015. A total of 113 cT1 patients were upstaged to pT3a, while 929 were staged as pT1. Demographic, perioperative and pathological variables were reviewed. We compared the clinico-pathological characteristics, perioperative morbidity and oncological outcomes between pT3a and pT1 groups. Multivariate regression evaluates variables associated with T3a upstaging. Recurrence-free survival (RFS) and overall survival analyses were performed. Survival curves were compared using log-rank test.

Results: The pT3a tumors were high complexity tumors (median RENAL score 8 vs. 7, p < 0.01), higher hilar (h) location (27.5 vs. 14.8%, p < 0.01), higher grade (57.5 vs. 38.2%, p < 0.01), and higher positive surgical margins (18.6 vs. 5.8%, p < 0.01. Patients with pT3a had a higher estimated blood loss, transfusion rate, ischemia time and overall complications, though there were no differences in median e-GFR decline and major (Grade III-V) complications. Five-year RFS was 78.5% for pT3a group vs. 94.6% for pT1 group (log-rank p < 0.01). Male gender (OR 2.2, p < 0.01), and R.E.N.A.L. score (OR 2.3, p = 0.01) were preoperative predictors of upstaging. We acknowledge limitations in our study, most are inherent problems of retrospective studies.

Conclusion: Perioperative morbidity, after partial nephrectomy, is acceptable in cT1/pT3 tumors in comparison to cT1/pT1; however, upstaged patients had a worse oncological outcome. cT1/pT3a tumors are associated with adverse clinico-pathological features. Preoperative risk predictors of upstaging were higher R.E.N.A.L. score and male gender.