Effectiveness of adjuvant chemotherapy for patients who undergo radical cystectomy without neoadjuvant chemotherapy: A retrospective cohort study of 115 advanced bladder cancer patients with pathological lymph node classification.

Objectives: We investigated the clinical outcomes of radical cystectomy without cisplatin-based neoadjuvant chemotherapy (NAC) and identified factors affecting the effectiveness of cisplatin-based adjuvant chemotherapy (AC).

Methods: Between September 2002 and February 2020, 288 bladder cancer patients who did not receive NAC underwent radical cystectomy. We retrospectively analyzed the recurrence rates, primary recurrence sites, recurrence-free survival (RFS), and overall survival (OS) of 115 advanced bladder cancer patients (pT3-4 or pN1-3) who were divided into the AC and observation groups. Subgroup analysis was performed, focusing on pathological stage.

Results: In total, 51 patients received AC, and 64 patients were observed. The median follow-up duration was 95 months. The recurrence rate was lower in the AC group than in the observation group (35.3% vs. 54.7%, p = 0.041). The rate of recurrences in the lymph node area (dissection site and proximal lymph nodes) was lower in the AC group (9.8% vs. 26.6%; p = 0.031). In the subgroup analysis of patients with pN1, the probability of RFS and OS was higher in the AC group than in the observation group. The hazard ratio for RFS and OS was 0.243 (95% confidence interval [CI]: 0.077-0.768) and 0.259 (95% CI: 0.082-0.816), respectively. The 5-year RFS and OS were significantly higher in the AC group (80.0% and 79.4%) than in the observation group (35.7% and 42.9%; p < 0.008 and p < 0.012, respectively).

Conclusions: AC improved RFS and OS in patients with pN1 disease who did not receive NAC and should be considered for this population.