Analysis of recurrence trends according to risk groups after renal cancer nephrectomy.

Introduction: Recurrence trends after renal cell cancer nephrectomy are not clearly defined.

Objective: To evaluate recurrence trends according to recurrence risk groups (RRG).

Material And Method: Retrospective analysis of 696 patients with renal cell cancer treated with nephrectomy between 1990-2010. Three RRG were defined according to the presence of anatomopathological variables (pTpN stage, nuclear grade, tumor necrosis [TN], sarcomatoid differentiation [SD], positive resection margin [RM]): -Low RG (LRG): pT1pNx-0 G1-4, pT2pNx-0 G1-2; no TN, SD and/or RM (+). -Intermediate RG (IRG): pT2pNx-0 G3-4; pT3-4pNx-0 G1-2; LRG with TN. -High RG (HRG): pT3-4pNx-0 G3-4; pT1-4pN+; IRG with TN and/or SD; LRG with SD and/or RM (+). The Kaplan-Meier method has been used to evaluate recurrence-free survival as a function of RRG. The log-rank test was used to evaluate differences between survival curves.

Results: The median follow-up was 105 (IQR 63-148) months. Of the total series, 177 (25.4%) patients presented recurrence: distant 15.9%, local 4.9% and 4.6% distant and local. The recurrence rate varied according to the RRG with values of 72.9% for HRG, 16.9% for IRG and 10.2% for LRG (p=.0001). Most cases in LRG presented single organ recurrence (72.2%) (p=.006). The LRG experienced recurrence as single metastasis in 50% of cases, compared to 30% and 18.6% in IRG and HRG, respectively (p=.009). The most common sites of recurrence were lung and abdomen. Lung recurrence predominated in the HRG (72.9%) (p=.0001) and abdominal, in the LRG (83.3%) with a tendency to significance (p=.15).

Conclusions: Recurrence rates (especially bone and lung) increase with higher RG. Single organ recurrences and single metastases are more frequent in LRG.