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

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

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

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.

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).

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