Predictive value of radiological response rate for pathological response to neoadjuvant chemotherapy and post-cystectomy survival of bladder urothelial cancer

Abstract

Objective: To determine the predictive value of the radiological response rate assessed by serial pelvic computed tomography scans for pathological response to neoadjuvant chemotherapy and clinical outcomes after radical cystectomy in bladder urothelial cancer patients. Methods: We retrospectively reviewed 59 patients with muscle-invasive bladder cancer who underwent radical cystectomy following neoadjuvant chemotherapy. Pretreatment and post-neoadjuvant chemotherapy computed tomography scans were evaluated by a single radiologist to determine the radiological response rate based on the largest diameter of the primary tumor. Association of the radiological response rate with pathological findings of the radical cystectomy specimen and post-radical cystectomy clinical outcomes were assessed. Results: The pathological complete response rate was 25% (n = 15) and the median (range) radiological response rate was 0.58 (0.00-1.00). The radiological response rate was significantly associated with ≤pT1. Patients with pathological downstaging to ≤pTa/is or pT1, compared with those with pT2≤ tumor, had significantly better post-radical cystectomy recurrence-free survival (2-year survival 92.0, 88.9, 36.8%, respectively, P < 0.0001), disease-specific survival (2-year survival 95.8, 88.9, 47.3%, respectively, P < 0.0001) and overall survival (2-year survival 91.7, 88.9, 40.1%, respectively, P < 0.0001). Patients with a higher radiological response rate (≥0.57) had significantly better post-radical cystectomy recurrence-free survival (2-year survival 89.7 vs. 48.1%, P = 0.0011), disease-specific survival (2-year survival 93.2 vs. 48.2%, P < 0.0001) and overall survival (2-year survival 90.0 vs. 39.0%, P < 0.0001). Multivariate analyses using the Cox proportional hazard model revealed that the radiological response rate was an independent predictor for favorable pT stage and recurrence-free survival. Conclusion: The radiological response rate determined by pretreatment and post-chemotherapy computed tomography scans predicts the pathological outcome and post-radical cystectomy prognosis, which is clinically relevant and useful for patient counselling and decision-making.