The critical role of lymph node dissection in selecting high-risk nonmetastatic renal cancer candidates for adjuvant therapy after nephrectomy

BACKGROUND: The role of lymph node dissection (LND) during nephrectomy for renal cell carcinoma (RCC) is controversial. We looked at the clinical usefulness of performing LND to stratify the risk of patients with RCC and select candidates for systemic treatment after nephrectomy. MATERIALS AND METHODS: We identified 730 patients with nonmetastatic RCC treated with nephrectomy and LND at a single center. We compared the accuracy and clinical usefulness of a base model including factors defining high-risk patients according to the S-TRAC trial [(pT3 and Grade≥2 and performance status score ≥1) or pT4] relative to the base model plus pN stage for the prediction of early progression after surgery. RESULTS: LN invasion resulted the most informative predictor of early progression (odds ratio: 6.39; 95% confidence interval [CI]: 3.26, 12.54; P < 0.0001). The accuracy was higher (P = 0.008) for the model implemented with pN (area under the curve: 0.76; 95% CI: 0.71, 0.80) as compared to the base model (area under the curve: 0.72; 95% CI: 0.68, 0.76). Performing LND to select patients for postoperative systemic treatment, resulted in a slightly higher net benefit as compared to a strategy defining risk on the base of factors other than pN. Patients with high-risk disease showed a large difference in the risk of progression according to pN-status (1-year risk: 58% [95% CI: 45, 72] for pN1; 31% [95% CI: 25, 38] for pN0; P < 0.001). CONCLUSIONS: Performing LND at the time of nephrectomy improves risk stratification, resulting into a small but nonnegligible clinical advantage for selecting high-risk patients for further treatment after surgery. Further trials should investigate whether high-risk pN1 patients would benefit from a different postoperative management.