Stage-specific effect of nodal metastases on survival in patients with non-metastatic renal cell carcinoma

To quantify the survival disadvantage related to the presence of exclusive nodal metastases (eNM) in patients with otherwise non-metastatic (M0) renal cell carcinoma (RCC). Data were retrieved from 12 institutional databases and yielded 3507 patients with T1-3N1-2M0 RCC treated with partial or radical nephrectomy. Cox regression analyses relied on T stage, Fuhrman grade and presence of eNM. Data were analysed using univariable, multivariable and stratified analyses. Overall 165 (4.7%) patients had eNM; of 2023 patients of stage T1, 23 (1.1%) had eNM, vs 20 of 448 (4.5%) for T2 and 122 of 993 (12.3%) for T3. In univariable analyses the presence of eNM increased the rate of cancer specific mortality (CSM) by 7.1 times. After adjusting for T stage and Fuhrman grade, in all patients eNM increased the rate of CSM by 3.2 times. In stratified analyses adjusted for Fuhrman grade, the increase in CSM related to the presence of eNM was 28.9, 4.3 and 2.5 times (all P < 0.001) for stages T1, T2 and T3, respectively. From the prognostic perspective, staging lymphadenectomy appears of most value in patients with T1-2 RCC, but the low prevalence of eNM questions the practical applicability of nodal staging in those patients. Conversely, in patients with T3 RCC, the prevalence and the prognostic impact of eNM might make a staging lymphadenectomy worthwhile.