Impact of Active Surveillance Versus Chemotherapy on Recurrence in Testicular Germ Cell Tumors: A Propensity Score–Weighted Analysis

Background: Testicular germ cell tumors (TGCTs) are the most common solid malignancies in young men. In real-world clinical practice, non-random treatment allocation may result in confounding by indication, as patients with a greater disease burden are more likely to receive chemotherapy. We evaluated the association between treatment strategy and recurrence-free survival using propensity score–based inverse probability of treatment weighting (IPTW). Methods: We retrospectively analyzed 114 patients who underwent radical orchiectomy for TGCT between 2015 and 2024. Patients were classified into active surveillance and chemotherapy groups. Stabilized IPTW was used to balance baseline clinicopathological characteristics. Recurrence-free survival was evaluated using Kaplan–Meier analysis and Cox proportional hazards regression. Residual post-weighting imbalance was addressed by additional covariate adjustment. Results: During follow-up, 29 of 114 patients (25.4%) experienced recurrence. Unadjusted Kaplan–Meier analysis demonstrated no statistically significant difference in recurrence-free survival between treatment groups (log-rank p = 0.150). Consistently, the unadjusted Cox proportional hazards model showed no statistically significant association between treatment strategy and recurrence-free survival (HR = 1.85, 95% CI 0.79–4.34; p = 0.158). After IPTW, treatment strategy remained not significantly associated with recurrence-free survival (HR = 0.96, 95% CI 0.43–2.13; p = 0.911). Additional adjustment for residual post-weighting imbalance yielded similar results (HR = 0.94, 95% CI 0.43–2.03; p = 0.876). Conclusions: After adjustment for measured baseline differences using IPTW, treatment strategy was not statistically significantly associated with recurrence-free survival. Given the limited number of recurrence events, wide confidence intervals, residual covariate imbalance, incomplete propensity-score overlap, and evidence of non-proportional hazards, these findings should be considered exploratory and should not be interpreted as evidence of equivalence.