Young age increases the risk of lymph-node metastasis in patients with muscle-invasive bladder urothelial carcinoma.

The risk of positive lymph nodes in patients with muscle-invasive bladder urothelial carcinoma (MIBC) can be used to guide treatment recommendations. However, little is known about the effect of age on lymph node positivity (LN+). This study aimed to evaluate the effect of age on LN+ in MIBC. We analyzed patients with stage T2–T4 bladder urothelial carcinoma who had not received preoperative radiotherapy, had at least one lymph node examined, and underwent cystectomy between 1998 and 2015. The Cochran–Armitage trend test and logistic univariate and multivariate analyses were used to evaluate the effect of age on LN+ in all T stages. In total, 15,624 patients with MIBC were identified, including 747 patients aged ≤50 years (4.78%), 2614 patients aged 50–59 years (16.73%), 4914 patients aged 60–69 years (31.45%), 5225 patients aged 70–79 years old (33.44%), and 2124 patients aged > 80 years (13.59%). In T2–T4 staging, LN+ was negatively correlated with age. After adjustment for several covariates, multivariate logistic regression analysis revealed that age was an independent risk factor for LN+. In this large SEER analysis, Young patients with MIBC have a higher risk of lymph node metastasis. This finding is worthy of further study and may eventually affect the treatment decisions of young patients.