Renal Cell Carcinoma with Isolated Lymph Node Involvement: Long-term Natural History and Predictors of Oncologic Outcomes Following Surgical Resection.

BACKGROUND: Renal cell carcinoma (RCC) with isolated lymph node (LN) involvement has historically been associated with poor prognosis. However, a subset of patients may experience long-term survival.
OBJECTIVE: To examine the natural history of RCC with isolated LN involvement following surgical resection with long-term follow-up, and to evaluate clinicopathologic features associated with disease progression and survival. DESIGN, SETTING, AND PARTICIPANTS: A total of 138 patients with isolated pN1M0 RCC underwent partial or radical nephrectomy and LN dissection from 1980 to 2010. INTERVENTION: Partial or radical nephrectomy with LN dissection. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS) were estimated using the Kaplan-Meier method. Associations between clinicopathologic features and oncologic outcomes were evaluated using Cox regression models. RESULTS AND LIMITATIONS: Median follow-up among survivors was 8.5 yr. The 5-yr and 10-yr MFS, CSS, and OS rates were 16% and 15%, 26% and 21%, and 25% and 15%, respectively. The median time to development of metastases was only 4.2 mo. On multivariable analysis, symptoms at presentation (hazard ratio [HR] 2.40; p=0.03), inferior vena cava tumor thrombus (HR 1.99; p=0.003), clear cell (HR 2.21; p=0.01) and collecting duct/not otherwise specified (HR 4.28; p<0.001) histologic subtypes, pT4 stage (HR 2.64; p=0.005), and coagulative tumor necrosis (HR 2.51; p<0.001) were independently associated with development of metastases. MFS rates at 1 yr after surgery were 71%, 63%, 33%, and 7% for patients with one, two, three, and four to five adverse features, respectively. Limitations include surgical selection bias.
CONCLUSIONS: Although isolated pN1 disease portends a poor prognosis, a small subset of patients experience durable long-term survival after surgical resection of isolated lymphatic metastases. Adverse prognostic features may enhance patient risk stratification and facilitate multimodal management approaches. PATIENT
SUMMARY: Although isolated lymph node metastases portend a poor prognosis, a small subset of patients experience long-term survival following surgical resection.