Urothelial cell carcinoma of the bladder in pediatric patients: a systematic review and data analysis of the world literature.
BACKGROUND
Urothelial cell carcinoma (UCC) of the bladder is exceedingly rare in pediatric patients. Limited data are available to guide management in this population.


METHODS
The authors 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 were abstracted, and adjusted logistic regression was used to identify factors associated with a combined outcome of recurrence or death.


RESULTS
One hundred 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, whereas 6.2% required secondary intervention. Tumor stage was TaN0M0 in 86.4% and low grade in 93.4%. Recurrence and death occurred in 8.6% and 3.7%, respectively. Mean time to recurrence or death was 8.6 months (standard deviation [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 (odds ratio [OR]: 2.4, 95% confidence interval [CI]: 1.02-5.6); ≥TaN0M0 disease (OR: 6.2, 95% CI: 2.5-15.6); and 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.