Introduction:
The receipt of neoadjuvant chemotherapy (NAC) followed by radical cystectomy (RC) remains standard of care for patients with muscle-invasive bladder cancer (MIBC). Although cross-sectional imaging is often obtained prior to RC, the ability of post-NAC imaging to predict clinical response is not well characterized. The purpose of this study is to evaluate the predictive value of computed tomography (CT) in assessing disease burden after NAC.
Methods:
Patients with MIBC having received platinum-based NAC prior to RC were identified following institutional review board approval. Patients without imaging following NAC were excluded. Demographics and clinicopathologic data were abstracted from the electronic medical record. Pre- and post-NAC CT scans were reviewed independently by a radiologist for evidence of bladder malignancy. Radiologic response was defined as a decrease in tumor size, decrease in tumor number, resolution of lymphadenopathy, or absence of T3 features. Radiologic complete response was defined as the absence of any feature of bladder malignancy on post-NAC CT. Pathologic complete response (PCR) was defined as pT0N0 and pathologic partial response (PPR) was defined as pTa, pT1, or pTis at RC. Cohen’s Kappa coefficients (K) were calculated to measure correlation with meaningful correlation defined as a K value greater than 0.25 or less than -0.25. McNemar’s test was used to test for normal disagreement.
Results:
A total of 155 patients having undergone NAC followed by RC were identified for analysis. PCR was achieved in 34% of patients and PPR was achieved in an additional 20%. 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 74.0% for PCR and 46.2% for PPR. Kappa coefficients were 0.0295 for complete response and -0.1241 for partial response. When including pTis in the definition of complete response (based on low likelihood of radiologic identification), K remained low at 0.0356. There was minimal correlation between radiographic lymphadenopathy and positive lymph nodes at RC (K = -0.0421) or radiographic T3 features and extravesical disease at RC (K = 0.0767). McNemar’s test determined significant disagreement overall between radiographic complete response and PCR (p = 0.023).
Conclusion:
Computed tomography findings after neoadjuvant chemotherapy correlate poorly with final pathology at radical cystectomy. Clinical decision making after neoadjuvant chemotherapy should not rely on imaging alone.
Funding: N/A
Image(s) (click to enlarge):
Computed Tomography Following Neoadjuvant Chemotherapy Does Not Predict Disease Burden Prior to Radical Cystectomy
Category
Bladder Cancer > Muscle Invasive Bladder Cancer
Description
Poster #237
Friday, Dec 3
4:00 p.m. - 5:00 p.m.
Bladder 7
Presented By: Syed M. Alam, MD
Authors:
Syed M. Alam, MD
Austin Martin, BS
Shaun Best, MD
Jeffrey Thompson, PhD
John A. Taylor, III, MD, MS