Highlighting En-Bloc Resection in Bladder Cancer Surgery

The development of en-bloc resection of bladder tumors (ERBT), wherein the tumor is removed in one piece to reduce the risk of tumor reimplantation, has been associated with a significant reduction in 1-year recurrence rates among patients with non–muscle-invasive bladder cancer (NMIBC), according to Jeremy Teoh, MBBS, FRCSEd, FCSHK, FHKAM.

At the 2026 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium, Teoh, assistant dean of External Affairs,associate professor in the Department of Surgery, and director of the Urology Centre at the Chinese University of Hong Kong Medical Centre, discussed the emergence of ERBT among patients with NMIBC, as well as research he conducted elucidating the benefit of adding Bacillus Calmette-Guérin (BCG) to the procedure to bolster outcomes among patients with high-risk disease, in a conversation with CancerNetwork.^1-3

First, he highlighted an overall benefit among patients treated with ERBT vs standard resection (SR) in the phase 3 EB-StaR study (NCT02993211) he conducted, with a significant reduction in 1-year recurrence rate at 29% vs 38%, respectively (P = .007).² Moreover, he touched upon subgroup analyses conducted in the study, showing particular benefit among patients with low- and intermediate-risk disease (HR, 0.50; 95% CI, 0.16-1.57; P = .2; HR, 0.55; 95% CI, 0.31-0.95; P = .032).

Next, Teoh outlined subsequent research which sought to address suboptimal outcomes observed among patients with high-risk disease treated with ERBT alone. In a post-hoc analysis of the EB-StaR study, intravesical BCG when added to ERBT achieved a significant reduction in 1-year recurrence-free survival at 5% (95% CI, 0%-14%) vs 33% (95% CI, 21%-43%) with ERBT alone.³ He concluded by suggesting that this combination of ERBT with adjuvant BCG may effectively cure most patients with bladder cancer.

Transcript:

In 1980, there was an attempt trying to introduce a surgical approach, it's called en-bloc resection, meaning that you try to mark the margins instead of resecting a tumor in a piece[-by-piece] of manner, you try to remove it en-bloc, which means remove [it in] one piece. We try to minimize the risk of tumor fragmentation and ensure a complete resection by assessing the margins so that we can be absolutely sure that all the tumors have been resected. In Hong Kong, I led the multicenter trial. It's called the EB-StaR trial, involving 13 centers, 350 patients, comparing en-bloc vs conventional transurethral resection of bladder tumor [TURBT].

We found that the surgeons with the same equipment, just by simple adoption of an en-bloc resection technique, were able to reduce 1-year recurrence rate from 38.5% to 28.1%. We found that in subgroup analysis, patients with low- [or] intermediate-risk benefitted the most from [en-bloc] surgery, which makes sense, because a good lower-risk surgery should cure. In high-risk patients, good surgery alone is not sufficient.

Then we looked into patients who received BCG as well, because there's an adjuvant treatment trying to control multifocality, patients with carcinoma in situ [CIS], et cetera. Predominantly, this is one of the major reasons why these high-risk diseases will occur in the future. We found that, in patients who underwent TURBT plus BCG, the 1-year recurrence rate is around 26.3% but recurrences occurred early, at 3 to 6 months [of treatment]. We believe these are probably more related to surgery technique leading to early disease recurrence.

Then in the other group, en-bloc resection, having an upfront cancer control, together with an adjuvant BCG treatment, we found that the 1-year recurrence rate is only 5% in patients with high-risk NMIBC. This is probably the way forward. We are therefore launching more studies to prove this point: good surgery plus a good adjuvant [treatment] should cure most patients with bladder cancer.

References

1. Teoh JYC. Optimizing surgical management of non-muscle-invasive bladder cancer. Presented at: 2026 ASCO Genitourinary Cancers Symposium. February 26-28, 2026. San Francisco, CA.
2. Teoh JYC, Cheng CH, Tsang CF, et al. Transurethral en bloc resection versus standard resection of bladder tumour: a randomised, multicentre, phase 3 trial. Eur Urol. 2024;86(2):103-111. doi:10.1016/j.eururo.2024.04.015
3. Teoh JYC, Wong CHM, Cheng CH, et al. Impact of intravesical Bacillus Calmette-Guérin therapy following transurethral en bloc resection of bladder tumour: post hoc analysis of a randomised, multicentre, phase 3 trial. Eur Urol Oncol. Published online November 1, 2025. doi:10.1016/j.euo.2025.09.008