van Hoogstraten LMC, van Gennep EJ, Kiemeney LALM, et al. - Findings revealed presence of occult lymph node metastases (LNM) in 4.3% of patients with cT2-4aN0M0 muscle-invasive bladder cancer (MIBC) with (near-) complete downstaging of the primary tumor after radical cystectomy (RC) plus pelvic lymph node dissection (PLND). This was irrespective of neoadjuvant chemotherapy (NAC) or clinical T-stage. A considerably worse survival was seen in patients with occult LNM.

• This study included patients with cT2-T4aN0M0 urothelial MIBC who received RC plus PLND with curative intent.

• A total of 4,657 patients from the Netherlands Cancer Registry (NCR) cohort and 760 patients from the NCR-BlaZIB cohort were incorporated in this analysis.

• There were 1,374 patients downstaged to  <(y)pT2, of those, 4.3% (N = 59) were found to have occult LNM 4.1% (N = 49) with cT2-disease and 5.6% (N = 10) with cT3-4a-disease.

• This was 4.0% in those without NAC or neoadjuvant radiotherapy (NAR), 4.5% in those with NAC, and 13.5% in those with NAR but the number of patients managed with NAR and downstaged disease was small.

• In the NCR and NCR-BlaZIB cohorts, the prevalence of  <(y)pT2N+ disease was 4.2% (N = 48) and 4.6% (N = 11), respectively.

• The median overall survival was 3.5 years vs 12.9 years for patients with  <(y)pT2N+ and  <(y)pT2N0, respectively.