Long-Term Oncologic Outcomes in Patients With Muscle Invasive Bladder Cancer Misclassified as Achieving a Complete Clinical Response to Neoadjuvant Chemotherapy

Abstract

Introduction: Correctly classifying patients with muscle invasive bladder cancer (MIBC) as achieving a complete clinical response (CCR) to neoadjuvant chemotherapy (NAC) is challenging without radical cystectomy (RC) pathology. The accuracy of clinical staging following NAC is debated, and the risk of occult residual MIBC is real. We present the rate and oncologic outcomes of patients who were misclassified as achieving a CCR to NAC. Materials and Methods: We utilized our prospective database of patients who achieved a CCR to NAC and elected active surveillance (AS). Patients with intravesical MIBC within 6 months of CCR classification were defined as potentially misclassified (mCCR). We used Kaplan-Meier curves to assess overall (OS), cancer-specific (CSS), and metastasis-free (MFS) survival and log-rank tests to evaluate differences between cohorts. Results: Fifty-four patients, median age of 70 years and follow-up of 49 months, were included. Six patients (11%) were mCCR, and all underwent delayed RC at a mean of 4.3 months after CCR classification. Pre-NAC hydronephrosis was more common in mCCR patients (67% vs 8%, P < .01). Five-year OS, CSS, and MFS for mCCR patients were 63% each, compared with 80%, 89%, and 93%, for the remaining patients. Log-rank tests demonstrated significantly lower OS (P = .03) and MFS (P = .05) in mCCR patients. Conclusions: We observed an 11% CCR misclassification rate. While mCCR patients had significantly worse OS and MFS compared with correctly classified CCR patients, we cannot know for certain how survival outcomes would have changed with immediate RC. Our findings are useful when describing the risks of misclassification to CCR patients contemplating AS.