Histotype predicts the rate of lymph node invasion at nephrectomy in patients with nonmetastatic renal cell carcinoma

Background: Lymph node invasion (LNI) at nephrectomy is one of the most important predictors of mortality in patients with nonmetastatic renal cell carcinoma (RCC). We analyzed the effect of histology on lymph node metastases at nephrectomy and its effect on survival in a contemporary cohort of patients with nonmetastatic RCC. Methods: Within the Surveillance, Epidemiology, and End Results database (2004-2015), we identified 100,060 patients with clear-cell, papillary, chromophobe, sarcomatoid, and collecting duct RCC, who underwent nephrectomy with or without lymph node dissection for nonmetastatic RCC. Logistic regression models, cumulative incidence plots, and competing-risks regression models were performed. Results: Overall, 10,590 patients underwent lymph node dissection for nonmetastatic RCC. Of these, LNI was recorded in 52 (7.0%), 615 (8.7%), 282 (13.9%), 316 (25.1%), 129 (38.3%), 45 (71.4%) patients with chromophobe, clear-cell, nonotherwise specified RCC, papillary, sarcomatoid, and collecting duct RCC histological subtypes, respectively. In logistic regression models, relative to clear-cell, papillary Odds ratio (OR 3.9), sarcomatoid (OR 6.3), collecting duct (OR 14.6) but not chromophobe RCC (OR 0.9; P = 0.5) independently predicted LNI at surgery. Moreover, in competing-risks regression models, LNI increased the risk of CSM 1.8-fold for sarcomatoid, 3.6-fold for clear-cell, 4.1-fold for papillary, and 6.7-fold for chromophobe histological subtype. Conclusions: Histology is an independent predictor of increased risk of LNI at nephrectomy. Moreover, the effect of pathological nodal stage on survival differs according to different histology.