Therapeutic decisions and outcome of patients with stage I testicular germ cell tumor: Single-centre experience.

Abstract

5029 Background: Testis cancer (TC) is the most common solid neoplasm affecting men aged 15 to 40, with most of diagnosis occurring at stage I. Despite excellent prognosis, optimal post-surgical management remains controversial, comprising adjuvant therapy (AT) or active surveillance (AS). Methods: Our study aimed to compare relapse-free survival (RFS) in patients (pts) with stage I TC undergoing AT [chemotherapy (CT) or radiotherapy (RT)], versus AS, between 2000 and 2023. Evolution of AT choices for seminomas was evaluated over different time periods (before 2014, 2014-2018, after 2018). Clinical histories of stage I TC treated at our institution were retrospectively collected. Traditional histopathological prognostic factors for relapse were assessed, and seminomas were reclassified according to the new EAU risk group classification. Overall survival (OS) was a secondary endpoint. Pts with inadequate follow-up, insufficient information, or histologies other than seminoma and nonseminoma were excluded. Results: Out of 240 cases, 184 (129 seminomas, 54 non-seminomas, 1 burned-out tumor) were eligible. AT was administered to 58.1% of seminomas and 57.4% of nonseminomas. In seminomas, AT was represented by CT in 40.3% and RT in 17.8% of cases. RT administration significantly decreased over time, representing 66.7% of AT before 2014, 9.1% between 2014 and 2018, and 0% after 2018. With a median follow-up of 56.9 months, 5-yr RFS rate was 94.6% and 84.7% for pts undergoing AT and AS, respectively (p=0.005). Particularly, 5-yr RFS rate was 92.5% vs 86.7% in seminomas (p=0.07), and 100% vs 79.9% in nonseminomas (p=0.015). Proportion of seminomas undergoing AT was 20.7% among those with T<4 cm and no rete testis invasion, 56.4% among those with 1 risk factor, and 82.2% among pts with 2 risk factors. AT was received by 3.2% and 96.8% of nonseminomas without and with lymphovascular invasion, respectively. In the new EAU classification, 31.4%, 48.8% and 19.8% of seminomas were classified into the very low, low, and high risk categories (8 cases not evaluable). Compared to the traditional classification, a lower proportion of pts resulted in the poorest risk category (19.8% vs 34.9%). AT receipt significantly increased with risk: very low 27.0%, low 67.8%, high 83.3% (p<0.001). 5-yr OS rate was 98.1% (99.1% in seminoma and 95.1% in nonseminoma). Conclusions: AT was associated with higher RFS rates across both histological types. AS and AT are both associated to excellent survival. A temporal trend in reduction of RT was observed. Further evaluations are needed to individualize treatment decisions. Histopathological risk factors and the new EAU risk classification provide valuable prognostic information, aiding in treatment stratification. Additionally, the EAU risk group classification emerges as a potential tool to better stratify seminoma pts and support the implementation of AS in lower risk categories.