Prediction of recurrence risk in patients with non-muscle invasive bladder cancer

Abstract

ObjectiveNon-muscle invasive bladder cancer (NMIBC) remains a common challenge in uro-oncology. There are conflicting reports on the risk prediction of bladder tumor recurrence. This study aimed to elucidate the recurrence rate of NMIBC in patients in Cancer Clinic of Shahid Beheshti Hospital in Iran and to investigate the impact of some related parameters on the recurrence risk prediction. MethodsThe data of 143 patients with NMIBC, who underwent treatment between January 2017 and January 2020 in our institution, were retrospectively assessed. The Cox regression analysis and Kaplan-Meier plot of recurrence-free survival were used to determine independent contributing factors for tumor recurrence. ResultsAmong patients with NMIBC, 83.9% were male, and 16.1% were female, with a mean age of 64.4 (standard deviation [SD] 12.9) years. During the follow-up, 71 (49.7%) patients showed tumor recurrence, with a mean recurrence time of 11.5 (SD 6.9) months. In the univariate analysis, age (≥65 years) (p=0.037), obesity (BMI ≥30 kg/m2) (p=0.004), no diabetes mellitus (p=0.005), smoking (current or former smoker) (p=0.001), immediate perfusion therapy (p=0.035), number of tumors (>3) (p<0.001), and stage tumor (T1 and Tis) (p=0.001) had independent significant effects on the recurrence of NMIBC. The multivariate Cox regression analysis indicated that preoperative obesity (hazards ratio [HR] 7.90; 95% confidential interval [CI] 4.01–15.55; p<0.001), current or former smoking (HR 1.85; 95% CI 1.07–3.20; p=0.027), and a high-grade tumor (HR 4.03; 95% CI 1.59–10.25; p=0.003) were significant predictors of tumor recurrence. The Kaplan-Meier plot of recurrence-free survival showed that obesity (log-rank p≤0.001), current or former smoking (log-rank p=0.001), and a high-grade tumor (log-rank p≤0.006) were associated with a shorter time interval until the first tumor recurrence. ConclusionsThe findings of the present study indicated the relatively high recurrence rate of NMIBC in Iran during 2017–2020. Obesity, smoking, and tumor grade were contributing factors for tumor recurrence in patients with NMIBC. Further large-scale prospective studies are suggested for the risk prediction of recurrence in patients with NMIBC.