Radical cystectomy plus chemotherapy in patients with pure squamous cell bladder carcinoma: a population-based study

Purpose: To test the effect of perioperative chemotherapy (CHT) on overall mortality (OM) and cancer-specific mortality (CSM) in patients with locally advanced or metastatic squamous cell carcinoma of the urinary bladder (SCC UB). Methods: Within the Surveillance, Epidemiology and End Results database (1988–2016), we identified 1,018 SCC UB patients (664 T_3–4aN₀M₀, 197 TanyN_1–3M₀ and 156 T_4bN_0–3 or M₁), who underwent radical cystectomy with or without perioperative chemotherapy administration. Inverse probability of treatment-weighting (IPTW), Kaplan–Meier plots and Cox-regression models (CRMs) were used. Results: CHT was administrated in 116 (17.5%) T_3–4aN₀M₀, 77 (39.1%) TanyN_1–3M₀ and 47 (30.1%) T_4bN_0–3 or M₁ patients. IPTW-adjusted 2-year cancer-specific survival (CSS) was 66.5 vs. 71.5% (p = 0.19), 60.9 vs. 29.5% (p < 0.001) and IPTW-adjusted 1-year CSS was 46.2 vs. 31.1% (p = 0.03) for CHT vs. no CHT administration in T_3–4aN₀M₀, TanyN_1–3M₀ and T_4bN_0–3 or M₁, respectively. In multivariable IPTW-adjusted CRMs, chemotherapy was an independent predictor of lower CSM in TanyN_1–3M₀ (HR 0.44) and in T_4bN_0–3 or M₁ (HR 0.60), but not in T_3–4aN₀M₀ (p = 0.6) patients. Virtually the same results were obtained on OM, as well as without IPTW-adjustment and after stratification according to age and gender. Conclusions: The use of perioperative CHT in patients with SCC UB confers survival benefit in the presence of T4b disease, lymph node or distant metastases. Conversely, patients with locally advanced disease but negative lymph node invasion do not benefit from its use. Pending higher quality data from prospective trials, these data should encourage the use of perioperative CHT in those high-risk patient groups.