Real-world utilization and outcomes of hematopoietic stem cell transplantation in testicular cancer.

Abstract

e17016 Background: Approximately 10–30% of patients with testicular cancer experience relapse or develop platinum-refractory disease, necessitating consideration for high-dose chemotherapy with hematopoietic stem cell transplantation (HSCT). However, contemporary real-world utilization patterns and outcomes for these patients remain incompletely characterized at a population level. Using a large federated electronic health record network (TriNetX), we identified adult patients with testicular cancer undergoing HSCT to describe their baseline demographics, pre-transplant chemotherapy exposure, and overall survival (OS) in routine clinical practice. Methods: We conducted a multicenter retrospective cohort study using the TriNetX research platform, a federated network of de-identified electronic health records from participating healthcare organizations. Adult patients (≥18 years) diagnosed with testicular cancer who underwent HSCT between January 1, 2010, and January 1, 2026, were identified using ICD-10 and procedure codes; patients with competing hematologic malignancies were excluded. The index date was defined as the date of the first HSCT. Baseline covariates included age, sex, race, ethnicity, and geographic region. Follow-up extended from the index date until death or the last recorded encounter. OS was estimated using the Kaplan–Meier method, and the association of covariates with mortality was evaluated using Cox proportional hazards models. Results: We identified 333 patients with testicular cancer who underwent HSCT. The mean age at transplant was 41 years (range 19–77). The cohort was predominantly White (76%) and 21% Hispanic. Prior to HSCT, the majority of patients had significant chemotherapy exposure: 224 (67%) received etoposide, 183 (55%) carboplatin, and 132 (40%) cisplatin. Additionally, 122 (36%) received ifosfamide and 95 (29%) paclitaxel. The median follow-up was 604 days (IQR 1,735), with a mean follow-up of 1,234 days. At the end of the observation window, 94 patients had died, corresponding to a crude mortality risk of 28.2%. The estimated 5-year overall survival was 65.3% by Kaplan–Meier analysis. The survival curve demonstrated an early decline in the first 12–24 months post-transplant, followed by a prolonged plateau consistent with long-term survivorship. Conclusions: The observed 5-year overall survival of approximately 65% indicates that HSCT achieves durable long-term survival for a substantial proportion of patients with relapsed or refractory testicular cancer in routine practice. These findings support the ongoing referral of appropriate candidates to specialized transplant centers and underscore the need for prospective studies to refine patient selection, optimize peri-transplant management, and evaluate novel consolidation strategies in this high-risk population.