O3332: Transitional Cell Carcinoma of the Bladder in Pediatric Patients: A Comparison with Adults within the National Cancer Database

Background: Transitional cell carcinoma of the bladder (TCCB) is a well-documented malignancy in adults but is rarely observed in the pediatric population. Given its rarity in children, we sought to leverage a large national database to analyze demographics, tumor characteristics, staging, and outcomes in pediatric patients compared to young adults (YA) and older adults (OA).

Methods: A retrospective cohort study was conducted using the National Cancer Database (NCDB) to identify patients diagnosed with TCCB, as specified by ICD-O-3 histology codes 8120–8131, during years of diagnosis 2004-2020. Patients were stratified into three age groups: Pediatric (PEDS) (≤ 21 years), Young Adult (YA) (22–50 years), and Older Adult (OA) (>50 years). Cases were required to be specified as stage Ta, Tis, T1, T2, T3, or T4. Cases of Ta, Tis, and T1 were further grouped as non-muscle-invasive bladder cancer (NMIBC), while T2-T4 were grouped as muscle-invasive bladder cancer (MIBC). Cases with missing survival data were excluded. Demographic variables, tumor characteristics, treatment modalities, and overall survival outcomes were analyzed using chi-square tests, Kaplan-Meier survival analysis, and Cox regression models.

Results: A total of 235 (0.1%) PEDS, 22,034 (4.3%) YA, and 488,182 (95.6%) OA cases were identified. In the pediatric cohort, TCCB was more prevalent in males (64%) and predominantly observed in non-Hispanic white individuals. Among pediatric cases, 226 (96.2%) had non-muscle-invasive tumors (NMIBC; Stage Ta, Tis, T1), including 6 (2.6%) with TCC in situ (TCCIS), a form known to be more aggressive and challenging to treat in children, while 9 (3.8%) had muscle-invasive tumors (MIBC; Stage T2-4). Surgery was the primary treatment modality for 231 of 235 (98.3%) pediatric patients. Additionally, 46 (19.6%) received intraoperative or adjuvant chemotherapy, compared to 31.7% in YA and 33.1% in OA. Pediatric patients demonstrated superior survival outcomes at 1, 2, 5, and 10 years compared to YA and OA. Across all age groups, invasive malignancies were associated with poorer prognoses than in situ disease.

Conclusion: This study represents the largest analysis of pediatric TCCB to date, highlighting a higher prevalence of aggressive histology (TCCIS) in children. Despite this, pediatric patients exhibited improved survival rates compared to YA and OA. Surgery remains the primary treatment across all age groups, though pediatric patients were less likely to receive intraoperative or adjuvant chemotherapy. These findings underscore the need for further investigation into optimal treatment strategies for pediatric TCCB.