Sentinel node detection in muscle-invasive urothelial bladder cancer is feasible after neoadjuvant chemotherapy in all pT stages,a prospective multicenter report

Purpose

To determine whether sentinel node detection (SNd) in muscle-invasive urothelial bladder cancer (MIBC) can be performed in patients undergoing neoadjuvant chemotherapy (NAC) and determine whether SNd is feasible in all pT stages, including pT0.

Background

Previous published series of SNd in MIBC have not included patients undergoing NAC, and systematic reports of pT0 patients w/wo NAC were absent. Translational immunological tumor research on MIBC focusing on SNd, in the era of NAC, requires technical feasibility. Additionally, SNd in MIBC requests further evaluations as a method for nodal staging.

Materials and methods

Ninety-nine patients with suspected urothelial MIBC were prospectively selected from six urological centers. After TUR-B and primary staging, 65 MIBC patients qualified for radical cystectomy. Precystectomy staging was cT2a-T4aN0M0, including 47 NAC patients and 18 chemo-naïve patients. All 65 patients underwent intraoperative SNd by peritumoral injection of 80 Mbq Technetium and Geiger probe detection. Postcystectomy staging was pT0-T4aN0-N2M0. SNs were defined by two calculations, SNdef1 and SNdef2.

Results

Totally 1063 lymph nodes were removed (total SNs; 222–227). NAC patients with pT0 (n = 24) displayed a true positive detection in 91.7 % by either SNdef, with a median of 3.0 SNs. NACpT >0 patients had a true positive detection in 87 % (SNdef1) and 91.3 % (SNdef2). In a univariate analysis, patient group neither NAC nor tumor downstaging influenced detection rates, regardless of SN definition. In total eight patients, 4/22 metastatic nodes were SNs while 18/22 were non-SNs.

Conclusions

Sentinel node detection in MIBC is feasible also in NAC patients, regardless of pT stage. SNd played no role in nodal staging.