Experts caution that the new consensus definition of cCR, combining imaging and cystoscopy, is for clinical trials only. Applying it prematurely in routine practice could harm patients, as its correlation with true pathologic response is still being validated with modern therapies.
The success of new treatments like immunotherapy and ADCs leads to more patients achieving a deep response. This high efficacy makes patients question the necessity of a radical cystectomy, a life-altering surgery, creating an urgent need for data-driven, bladder-sparing protocols.
The consensus for "event-free survival" (EFS) in bladder-sparing trials is now highly inclusive, counting even high-grade superficial (non-muscle invasive) relapses as events. This is a deliberately conservative choice to maximize patient safety and preempt the risk of these relapses leading to metastasis.
Historically, bladder-sparing options were primarily for patients unfit for radical cystectomy. Now, with advances in surgical techniques and perioperative care, fewer patients are deemed truly ineligible for surgery. This shift means new bladder-sparing strategies are being developed for a much broader patient population.
While circulating tumor DNA (ctDNA) is a powerful prognostic marker, it is not yet part of the formal "clinical complete response" definition for bladder-sparing trials. Experts lack data on its ability to predict the superficial, non-muscle invasive relapses common in this setting.
During the consensus meeting, patient advocates successfully argued for a highly robust definition of "event-free survival." The final definition counts not just cancer recurrence, but also the need for any additional standard-of-care treatment—including intravesical therapy—as an "event," reflecting the patient's perspective on what constitutes a successful outcome.