Abstract 516P
Background
As the characteristics and outcome associated with relapse in seminomatous testicular germ cell tumors are still unclear, this study aims at evaluating the differences between early and late relapse in this cohort of patients.
Methods
We performed a retrospective analysis including 348 patients with seminomatous testicular germ cell tumors, who were treated in or referred to our department from 2000 to 2020, analysing the patient characteristics as well as follow-up. Early relapse was defined as tumour recurrence < 12 months after successful treatment.
Results
69 (20%) patients relapsed during a median follow-up of 34 months [4-87]. The predominant site of relapse was the retroperitoneal space (75%). Relapse was most commonly treated with chemotherapy (49%), followed by chemotherapy plus post-chemo retroperitoneal lymph node resection (RPLND) (20%) or RPLND alone (14%). Of the 69 relapsing patients, 29 (42%) patients had an early relapse and 40 (58%) patients a late relapse. Patients with early relapse showed a significantly higher number of clinical stage 2C-3 disease (41% vs. 13%, p=0.006), S-stage ≥ 2 (50% vs. 23%, p=0.027) as well as a higher IGCCCG risk group (p=0.027) at diagnosis compared to patients with late relapse. Both groups did not show any difference regarding the occurrence of numerous relapses (n=11, p=0.943). Of those with numerous relapses, all patients with late relapses (n= 5) had clinical stage 1 at diagnosis and were treated with active surveillance (n=4) or one cycle of carboplatin (n=1), while the majority (5/6, 83%) of all patients with early relapses initially had metastatic disease and received chemotherapy. In the Kaplan-Meier estimates, early relapse was associated with a significantly reduced overall survival compared to late relapse (p=0.013), however median overall survival was not reached.
Conclusions
In our study, relapse in seminoma occurred in 20% of all patients. Of note, early relapses were associated with a higher metastatic burden and worse prognosis at diagnosis compared to late relapses, leading to a reduced overall survival in early relapsing seminoma patients compared to late relapsing patients. Consequently, treating physicians should be aware of these patients portending a dismal prognosis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Pia Paffenholz, Axel Heidenreich.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.