To investigate the relationship between mean lymph node diameter and clinicopathological features in patients with renal cell carcinoma undergoing radical nephrectomy and its impact on prognosis.

The clinicopathological data of 99 patients with renal cell carcinoma who underwent radical nephrectomy in 909th Hospital of Joint Logistics Support Force from January 2015 to June 2019 were retrospectively analyzed. All patients were followed up for 3 years. According to the follow-up results, the patients were divided into good prognosis group (n=76) and poor prognosis group (n=23). The relationship between mean lymph node diameter and clinicopathological characteristics of patients was analyzed. The operating characteristic curve (ROC) was drawn, and the area under the curve (AUC) was calculated to evaluate the predictive value of mean lymph node diameter on the prognosis of patients. Univariate and multivariate Logistic regression were used to analyze the prognostic factors of renal cell carcinoma.

The average diameter of lymph nodes was higher in patients with tumor diameter >7 cm, Fuhrman grade 3-4, microvascular invasion, capsule invasion, adrenal invasion and perirenal fat invasion (P<0.05). The AUC value of mean lymph node diameter in predicting the prognosis of patients was 0.869, 95%CI was 0.787-0.951, the sensitivity was 0.825, the specificity was 0.750, and the cut-off value was 0.555 cm (P<0.05). Multivariate regression analysis showed that tumor diameter >7 cm (OR=26.722, 95%CI=1.721-414.890, P<0.05), capsule invasion (OR=6.923, 95%CI=1.067-44.927, P<0.05), venous invasion (OR=15.307, 95%CI=1.031-227.179, P<0.05), adrenal invasion (OR=44.559, 95%CI=3.901-508.967, P<0.05), mean lymph node diameter >0.555 cm (OR=16.284, 95%CI=1.106-239.667, P<0.05) were independent risk factor for poor prognosis. Kaplan-Meier risk curve analysis found that the cumulative risk of adverse prognosis in patients with average lymph node diameter >0.555 cm was higher than that in patients with average lymph node diameter ≤0.555 cm (Log-Rank=22.469, P<0.05).

In patients of renal cell carcinoma without lymph node metastasis, mean lymph node diameter is associated with adverse pathological features and is an independent prognostic factor of patients, which may have certain clinical significance in judging prognosis and making individualized treatment plans.