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 trial's 57.1% pathologic complete response (pCR) rate is deceptively conservative. It categorized patients who responded well but declined surgery as non-responders, suggesting the treatment's true biological efficacy is even higher than the already impressive reported figure.

In the SUNRISE 2 trial, 44% of patients had no detectable tumor after pre-treatment resection. This high baseline inflates the final clinical complete response (CR) rates (e.g., 59% in the control arm), making CR a misleading indicator of the actual therapeutic benefit, which was a much smaller improvement over baseline.

The SUNRISE 2 trial's chemoradiation arm showed unexpectedly strong results. This is likely due to a protocol requiring a repeat resection (RIT-URBT) before randomization, which weeded out aggressive tumors and selected a patient population with a better prognosis, making the control arm unusually difficult to beat.

Some oncologists are stopping guideline-supported perioperative treatment regimens early if a patient achieves a pathologic complete response (pCR) from neoadjuvant therapy alone. This practice is considered premature and risky, as data from dedicated de-escalation trials like VOLGA is not yet available to support it.

Clinical Complete Response (cCR), assessed by imaging and biopsy, is the primary endpoint for avoiding surgery in new trials. However, these tools are known to be unreliable, potentially missing up to 25% of residual post-mucosal tumors and leading to undertreatment.

The efficacy of new bladder cancer drugs in single-arm trials is hard to assess because of concurrent improvements in surgical technology. Modern scopes allow for more complete resection of CIS tumors, meaning a "complete response" may be due to the surgery before the drug is even administered, not the drug itself.

With pathologic complete response rates approaching 67% in patients completing neoadjuvant EV-Pembro, a majority of cystectomies are now removing cancer-free bladders. This creates an ethical and clinical imperative to rapidly launch prospective trials to validate bladder preservation strategies and avoid overtreatment.

The control arm relapse rate in the SUNRISE 2 trial was only ~20%, while in the EV-303/KEYNOTE-905 trial it was ~60%. This huge discrepancy highlights that current clinical staging and selection criteria are poor at identifying patient risk, signaling an urgent need for better stratification tools like ctDNA for more effective clinical trials.