Tumor Infiltrated Hilar and Mediastinal Lymph Nodes are an Independent Prognostic Factor for Decreased Survival After Pulmonary Metastasectomy in Patients With Renal Cell Carcinoma

Purpose: Surgical resection remains the most effective treatment in patients with pulmonary metastasis of renal cell carcinoma. To our knowledge the prognostic significance of mediastinal and hilar lymph node metastasis during pulmonary metastasectomy in patients with renal cell carcinoma is unknown. We analyzed the value of computerized tomography to predict mediastinal/hilar lymph node involvement as well as the impact of systematic lymphadenectomy on survival in patients with pulmonary renal cell carcinoma metastasis. Materials and Methods: We analyzed survival in 110 patients who underwent resection of pulmonary metastasis of renal cell carcinoma using the Kaplan-Meier method. Multivariate analysis was done by Cox regression analysis. Results: Lymph node metastasis was histologically proved in 35% of patients. Metastasis was not associated with initial tumor grade, lymph node status, the number of pulmonary metastases or recurrent pulmonary metastasis. Computerized tomography had 84% sensitivity and 97% specificity to predict lymph node metastasis. Sensitivity was markedly better for detecting mediastinal than hilar lymph node metastasis (90% vs 69%). Patients with lymph node metastasis had significantly shorter median survival than patients without lymph node metastasis (19 vs 102 months, p <0.001). Multivariate analysis revealed that tumor infiltrated mediastinal lymph nodes were an independent prognostic factor for patient survival. Match paired analysis showed that after lymph node dissection patients showed a trend toward improved survival. Conclusions: Mediastinal and hilar lymph node metastases significantly correlate with decreased survival. Systematic lymphadenectomy provides valuable information on staging and prognosis in patients with pulmonary metastasis of renal cell carcinoma, and may prolong survival.