Abstract Code: IUC26664-89
De-escalated management of stage I seminoma: three decades of real-world outcomes
M.P. Juan Gonzalez 1, C. Martinez Martinez 1, A.J. Montalban Valverde 1, P.A. Barranzuela Decoll 1, Y. El Farh Boumajdil 1, E.J. Soria Hernandez 1, J.A. Mendez Garcia 1, E. Adrover Cebrian 1, A. Fernandez Aramburo 1
(1) Complejo Hospitalario Universitario de Albacete – Spain
Objective: To evaluate long-term outcomes, relapse patterns and clinicopathological factors associated with recurrence in patients with clinical stage I seminoma managed in routine practice over three decades.
Methods: We performed a retrospective single-centre study including patients diagnosed with clinical stage I seminoma between 1993 and 2025. Baseline clinicopathological features, treatment strategy after orchiectomy, relapse events and relapse timing were collected. Post-orchiectomy management was classified as active surveillance or adjuvant carboplatin. Associations between clinicopathological variables and relapse were explored using descriptive statistics and Cramér’s V.
Results: A total of 113 patients were included. Median age at diagnosis was 36 years. Overall, 21.2% had stage IB disease. Tumour size was greater than 4 cm in 56.0% of patients, rete testis invasion was present in 26.5%, and lymphovascular invasion was identified in 16.8%. After orchiectomy, 59.3% of patients were managed with active surveillance and 39.8% received adjuvant carboplatin. Six relapses were observed, corresponding to an overall relapse rate of 5.3%. All relapses occurred in patients initially managed with surveillance. Mean time to relapse was 17.2 months. Among the evaluated pathological factors, lymphovascular invasion showed the strongest association with relapse (Cramér’s V 0.30; p=0.006), whereas the absolute number of events limited further multivariable analysis.
Conclusions: In this real-world cohort of clinical stage I seminoma, relapse rates were low and all recurrences occurred after surveillance, supporting the overall safety of a de-escalated post-orchiectomy strategy when combined with structured follow-up. Lymphovascular invasion emerged as a potential marker of relapse risk in this dataset, although the small number of events precludes definitive conclusions. These findings support individualized counselling and highlight the value of long-term real-world series to refine risk-adapted management in stage I seminoma.