Testicular germ cell tumor survival among children, adolescents, and young adults: A population-based retrospective cohort study.

Abstract

10035 Background: While testicular germ cell tumor (TGCT) overall survival (OS) exceeds 90%, some patient groups, such as adolescents, have inferior event free survival (EFS) outcomes. There is a paucity of granular, population-derived data about outcomes in children, adolescents, and young adults (CAYA) with TGCT, limiting a deeper understanding of the factors that impact their survival. Methods: All male CAYA (ages 11-21 years) in Ontario, Canada diagnosed with TGCT between 1992-2021 were identified using provincial cancer registries. Detailed disease and treatment characteristics were chart abstracted for ~2/3 of the cohort and determined through health administrative databases for the remainder. We assessed 5-year OS and EFS (first of death, recurrence/progression, or subsequent malignant neoplasm [SMN]) using Kaplan-Meier analysis and the log rank test. Follow-up started at TGCT diagnosis, except for survival after SMN or recurrence, where follow-up started at event date. Results: 748 TGCT patients were identified; 521 were chart abstracted and thus had EFS data available. Median age at diagnosis was 19 years (interquartile range:18-21) and 83.6% had non-seminoma histology. OS and EFS ± standard error (SE) were (94.7 ± 0.8 %, n=748) and (76.4 ± 1.9%, n=521), respectively. Among patients with chart abstracted data, OS and EFS differed by cancer extent at diagnosis and were lowest among CAYA with non-lung organ metastases (Table). Patients who underwent retroperitoneal lymph node dissection (RPLND) for initial treatment (91/521) had higher survival than those who did not (OS 96.6 ± 1.9% vs 93.7 ± 1.2%, p=0.04; EFS 87.6 ± 3.5 % vs 74.1 ± 2.1 %, p=0.0008), particularly CAYA with lung-only organ metastases. OS post SMN (n=28) was 77.3 ± 8.2%, with lower OS after non-TGCT SMN (50.8 ± 14.4%, n=13) than second primary TGCT (100 ± 0%, n=15), p=0.002. OS after recurrence/progression (n=116) was superior in the 59 who did not receive chemotherapy at initial diagnosis (89.7 ± 4%) compared to the 57 who had initial chemotherapy (65.9 ± 6.4%; p=0.0001). Conclusions: CAYA with TGCT have low EFS, consistent with previous studies. The extent of metastasis is a significant predictor. Efforts are needed to improve the survival outcomes of young TGCT patients with organ metastasis at diagnosis, and those who recur or develop a non-TGCT SMN. [Table: see text]