Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Relapsed and Refractory Germ Cell Tumors: A Single-Center Experience

Background: High-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is an established salvage therapy for relapsed or refractory (R/R) germ cell tumors (GCTs). Methods: We conducted a retrospective analysis of 9 patients (23-41 years of age) with relapsed/refractory (R/R) GCTs treated according to the Swedish-Norwegian Testicular Cancer Group Clinical Protocol (SWENOTECA), at the Specialized Hospital for Active Treatment of Hematological Diseases (SHATHD) in Sofia, Bulgaria. The study evaluates the efficacy and safety of HDCT followed by ASCT in R/R GCTs eligible for second-line consolidation. Results: The median follow-up was 39.3 months. Following ASCT, the overall response rate (ORR) was 33.3%, consisting entirely of complete responses (CR). The 1-year OS and PFS were both 44.4%. Notably, Kaplan-Meier curves for OS and PFS reached a plateau after 24 months (33.3%), showing that long-term durable remission in these patients is achievable. Although grade 3–4 toxicities were observed, there was no treatment-related mortality. Conclusion: Tandem HDCT followed by ASCT is a safe and effective salvage strategy for R/R GCTs, offering predictable toxicity and curative potential, which is proven by the observed survival plateau. While tandem cycles are the current standard, the upcoming TIGER trial results will determine the future necessity of further intensification.