The Need for Interim Assessment of Neoadjuvant Chemotherapy Response for Muscle Invasive Bladder Cancer-Can We Help Prevent Definitive Treatment Delay in Nonresponders?

Clinical Upstaging After Neoadjuvant Chemotherapy Impacting Eligibility for Vaginal-sparing Cystectomy: Identifying Bladder Cancer Patients Who May Benefit From Interim Imaging

OBJECTIVE

Limited data exist on the frequency with which clinical progression during neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) impacts eligibility for a vaginal-sparing surgical approach or on the utility of interim imaging assessment. We sought to evaluate the incidence of clinical upstaging following NAC that would render a patient ineligible for a vaginal-sparing cystectomy.

METHODS

Eighty-nine female patients with non-metastatic MIBC treated with NAC and radical cystectomy (RC) (2012-2023) were retrospectively reviewed. Tumor location(s) was determined from transurethral resection of bladder tumor operative reports. Pre- and post-NAC clinical staging was determined from imaging. Outcomes of interest included clinical upstaging and upstaging to vaginal invasion after NAC.

RESULTS

75/89 patients had pre- and post-NAC imaging. Fifty-five had no change in clinical staging, 6 patients were upstaged (4 cT2→cT3, 2 cT3→cT4), and 14 patients were downstaged (13 cT3→cT2, 1 cT4→cT2). Of the 75 patients with pre- and post-NAC imaging, 39 had trigone tumors. Of these, 28 had no change in clinical staging, 2 were upstaged (1 cT2→cT3, 1 cT3→cT4) and 9 were downstaged (8 cT3→cT2, 1 cT4→cT2). Overall, 6/75 (8%) of patients demonstrated clinical upstaging after NAC. 2/39 (5%) of patients with trigone tumors clinically progressed after NAC and both had vaginal invasion (pT4) on final pathology.

CONCLUSION

Although clinical upstaging after NAC was infrequent, 5% of patients with trigonal MIBC were rendered ineligible for vaginal-sparing cystectomy following NAC due to progression. Interim imaging assessment may identify non-responders and preserve eligibility for vaginal-sparing RC.

Predictive Value of Computed Tomography Following Neoadjuvant Chemotherapy for Muscle Invasive Bladder Cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) prior to radical cystectomy (RC) remains standard treatment for select patients with muscle-invasive bladder cancer (MIBC). Although computed tomography (CT) is often obtained prior to RC, its ability to predict pathologic response is poorly characterized.

OBJECTIVE

The purpose of this study is to evaluate the predictive value of CT in assessing disease burden after NAC.

METHODS

Patients with MIBC having received NAC prior to RC were identified. Pre- and post-NAC CT scans were reviewed by an abdominal radiologist. The correlation between pathologic complete response (PCR) and radiologic complete response (RCR) was determined as the primary aim. As a secondary aim, the correlation between pathologic partial response (PPR) and radiologic partial response (RPR) was determined. Logistic regression analysis was utilized to determine the predictive value of CT in determining disease burden at RC.

RESULTS

A total of 141 patients were identified for analysis. PCR and PPR was achieved in 34% and 16% of patients, respectively. The positive predictive value of post-NAC CT was 53.5% for PCR and 28.8% for PPR. The negative predictive value of post-NAC CT was 73.5% for PCR and 46.2% for PPR. There was no significant association between RCR and PCR (OR 1.13, p = 0.67). Similarly, there was no meaningful association between RPR and PPR, lymph node involvement, or presence of extravesical disease.

CONCLUSIONS

CT findings correlate poorly with final pathology at RC and should not be used to evaluate local disease burden.

A longitudinal study evaluating interim assessment of neoadjuvant chemotherapy for bladder cancer

OBJECTIVES

To evaluate the usefulness of radiological re-staging after two and four cycles of neoadjuvant chemotherapy (NAC), the impact of re-staging on further patient management, and the correlation between clinical and final pathological tumour stage at radical cystectomy (RC).

PATIENTS AND METHODS

We conducted a longitudinal, single-centre, cohort study of prospectively collected consecutive patients who underwent NAC and RC for urothelial muscle-invasive bladder cancer between July 2001 and December 2017. Patients underwent repeated computed tomography scans for re-staging after two cycles of NAC and after completion of NAC before RC.

RESULTS

Of 180 patients, 110 had ≥four cycles of NAC and had complete imaging available. In the entire cohort, further patient management was only changed in 2/180 patients (1.1%) after two cycles of NAC based on radiological findings. Patients who were stable after two cycles but then downstaged after at least four cycles of NAC had a similarly lowered risk of death (hazard ratio [HR] 0.53). Only one patient downstaged after two cycles was subsequently upstaged after four cycles. Clinical downstaging was observed in 51 patients (46%), 55 patients (50%) had no change in clinical stage and four patients (3.6%) were clinically upstaged. Patients clinically downstaged after four cycles of NAC had a lower risk of death (HR 0.49, 95% confidence interval 0.25-0.94; P = 0.033) compared to those with no change or upstaged after completion of NAC.

CONCLUSIONS

Re-staging of muscle-invasive bladder cancer after two cycles of NAC offers little additional information, rarely changes patient management, and may therefore be omitted, whereas re-staging after completion of NAC by CT is a strong predictor of overall survival.