A comparison of pediatric, adolescent, and adult testicular germ cell malignancy

Background: Testicular germ cell tumors (T-GCTs) occur from infancy to adulthood, and are the most common solid tumor in adolescent and young adult males. Traditionally, pediatric T-GCTs were perceived as more indolent than adult T-GCTs. However, there are few studies comparing these groups and none that specifically evaluate adolescents. Methods: An institutional database of T-GCT patients was reviewed and patients were categorized into Pediatric, aged 0-12 years, Adolescent, aged 13-19 years, and Adult, older than 20 years, cohorts. Demographics, tumor characteristics, disease stage, treatment, event-free survival (EFS), and overall survival (OS) were compared between groups. Results: Overall, 413 patients (20 pediatric, 39 adolescent, 354 adult) met study criteria and were followed for a median of 2.0 years (0.1-23.6). Adolescents presented with more advanced stage than children (P=0.018) or adults (P=0.008). There was a higher rate of events in Adolescents (13, 33.3%) than in Adults (61, 17.2%) or Children (2, 10.0%). Three-year EFS was 87.2% in the Pediatric group, 59.9% in Adolescents and 80.0% in Adults (P=0.011). In a multivariate analysis, controlling for stage, IGCCCG risk, and histology, the hazard ratio (HR) for an event was: 1 (Reference) for Adults, HR=0.82 (95% CI 0.19-3.46; P=0.33) for the Pediatric group, and HR=2.22 (95% CI 1.21-4.07; P=0.01) for Adolescents. Five-year OS was 100% in the Pediatric group, 84.8% in Adolescents, and 92.8% in Adults (P=0.388). Conclusion: Lower EFS in adolescent T-GCT patients was observed than in either children or adults. Elucidating factors associated with inferior outcomes in adolescents is an important focus of future research.