Accuracy of clinical nodal staging and factors associated with receipt of lymph node dissection at the time of surgery for nonmetastatic renal cell carcinoma

Abstract

Introduction: The benefit of lymph node dissection (LND) in renal cell carcinoma (RCC) remains poorly defined. Despite this uncertainty, the American Urological Association (AUA) guideline on localized renal cancer recommends that LND be performed for staging purposes when there is suspicion of regional lymphadenopathy on imaging. Using the National Cancer Database (NCDB), we sought to determine how much of a departure the new AUA guideline is from current practice. We hypothesized that practice patterns would reflect the "Expert Opinion" recommendation and that patients who are clinical lymph node (cLN) positive would receive a LND more often than those who are cLN negative. Additionally, we sought to determine factors that would trigger a LND as well the accuracy of clinical staging by examining the relationship between cLN and pathologic lymph node (pLN) status of patients who received a LND.

Materials and methods: The NCDB was queried for patients with nonmetastatic RCC who underwent partial nephrectomy or nephrectomy from 2010 to 2014. Patient sociodemographic and clinical characteristics were extracted. Frequency distributions were calculated for patients with both cLN and pLN status available. Of patients who received a LND, sensitivity, specificity, and positive/negative predictive values (PPV/NPV) of cLN status for pLN positivity were calculated. Logistic regression models were used to examine association between clinical and socioeconomic factors and receipt of LND. Propensity score matching was used in sensitivity analyses to examine potential for reporting bias in NCDB data.

Results: We identified 110,963 patients who underwent surgery for RCC, of whom 11,867 (11%) had LND performed at the time of surgery. cLN and pLN information were available in 11,300 patients, of which 1,725 were preoperatively staged as having positive cLN. More LNDs were performed per year for patients who were cLN negative than cLN positive. Of patients who received a LND, the majority of patients were cLN negative across all clinical T (cT) stages. Multivariable analysis showed that all patients who had care at an academic/research institution (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.43-1.74) and had to travel >12.5 to 31.0 miles and >31.0 miles to a treatment center (OR: 1.08, 95%CI: 1.01-1.15 and OR: 1.28, 95%CI: 1.20-1.36, respectively) were more likely to get a LND. As cT stage increased from cT2-4, the risk of LND increased (OR range: 4.7-7.90, respectively). Patients who were cLN positive were more likely to receive a LND at the time of surgery (OR: 18.68, 95%CI: 16.62-21.00). Of the patients who received a LND, clinical staging was more specific than sensitive.

Conclusion: More patients received a LND who were cLN negative compared to patients who were cLN positive. Patients who were cLN positive were more likely to receive a LND. Treatment center type, distance to treatment center, cT stage, and cLN positivity were factors associated with LND receipt.

Keywords: Clinical nodal status; Lymph node yield; Lymphadenectomy; NDCB; National Cancer Database; Pathological nodal status; Renal cell carcinoma.