Urothelial Cell Carcinoma of the Bladder in Pediatric Patients: A Systematic Review and Data Analysis of the World Literature

Abstract Background Urothelial cell carcinoma (UCC) of the bladder is exceedingly rare in pediatric patients. Limited data is available to guide management in this population. Methods We systematically searched MEDLINE, Cochrane Library and Google Scholar (through February 2019) for case reports and series to summarize data regarding presentation, evaluation, management, and follow-up for patients ≤ 18 years diagnosed with UCC of the bladder. Patient-level data was abstracted and adjusted logistic regression was used to identify factors associated with a combined outcome of recurrence-or-death. Results One hundred and two articles describing 243 patients from 26 countries met criteria. Average age was 12.5 years, 32.6% were female, 15.3% had medical comorbidities, and 13.2% had known risk factors for bladder cancer. Initial management was transurethral resection in 95.5% of patients, while 6.2% required secondary intervention. Tumor stage was TaN0M0 in 86.4% and 93.4% were low-grade. Recurrence and death occurred in 8.6% and 3.7%, respectively. Mean time to recurrence-or-death was 8.6 months (SD 7.6) for 10.7%. Mean disease free follow-up without recurrence-or-death was 56.9 months (SD 54.2) for 89.3%. Patients with comorbidities, risk factors or family history (OR: 2.4, 95% CI: 1.02-5.6), ≥TaN0M0 disease (OR: 6.2, 95% CI: 2.5-15.6), and with larger tumors at diagnosis (OR: 1.7, 95% CI: 1.2-2.4) had significantly greater adjusted odds of recurrence-or-death after initial treatment. Conclusion Based on pooled results, disease recurrence-or-death occurred in 10.7% of pediatric patients and within 9 months for most and within 32 months for all patients. This may suggest that low-grade and stage UCC of the bladder in pediatric patients can be systematically monitored for at least 3 years. However, prospective evaluation of this clinical strategy is warranted.