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

person Rand Ajaj Child Health Evaluative Sciences, The Hospital for Sick Children Research Institute, Toronto, ON, Canada info_outline Rand Ajaj, Cindy Lau, Sumit Gupta, Nancy N. Baxter, Rinku Sutradhar, Jason D. Pole, Sarah Malkiel, Furqan Shaikh, Paul C. Nathan

Authors person Rand Ajaj Child Health Evaluative Sciences, The Hospital for Sick Children Research Institute, Toronto, ON, Canada info_outline Rand Ajaj, Cindy Lau, Sumit Gupta, Nancy N. Baxter, Rinku Sutradhar, Jason D. Pole, Sarah Malkiel, Furqan Shaikh, Paul C. Nathan Organizations Child Health Evaluative Sciences, The Hospital for Sick Children Research Institute, Toronto, ON, Canada, Cancer Research Program, ICES, Toronto, ON, Canada, Division of Haematology/Oncology, The Hospital for Sick Children, Toronto, ON, Canada, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, VIC, Australia, Queensland Digital Health Centre and Centre for Health Sciences Research, The University of Queensland, Brisbane, Australia, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel Hashomer, Israel Abstract Disclosures Research Funding Canadian Institutes of Health Research (CIHR). RA is supported by the Ontario Graduate Scholarship (OGS) through the University of Toronto and the Research Training Competition (RESTRACOMP) award through the Hospital for Sick Children. 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. 5-year survival ± SE (%). Cancer Extent n=512 OS/EFS By Cancer extent OS/EFS by Initial RPLND for Each Cancer Extent Category EFS* OS* EFS OS No Yes p No Yes p No mets n=377 81.9 ± 2.0 97.6 ± 0.8 80.1 ± 2.2 97.4 ± 2.6 0.002 97.3 ± 0.9 100 ± 0 0.1 Lymph node mets only n=34 90.9 ± 5.0 97.0 ± 3.0 88.9 ± 7.4 93.3 ± 6.4 0.5 100.0 ± 0 93.3 ± 6.4 0.9 Lung only organ mets (± lymph) n=68 57.2 ± 6.0 88.2 ± 3.9 45.0 ± 7.7 76.9 ± 8.3 0.006 80.8 ± 6.1 100.0 ± 0 0.008 Other organ mets (± lymph/lung) n=33 39.4 ± 8.5 63.6 ± 8.4 29.2 ± 9.3 66.7 ± 15.7 0.03 58.3 ± 10.0 77.8 ± 13.9 0.2 *p<.0001.