Before Orchiectomy: Gonadal Function in Testicular Germ Cell Tumors-A Narrative Review.

Testicular germ cell tumors (TGCTs) are the most common solid malignancy in young men and are highly curable, making reproductive and endocrine survivorship central concerns. Gonadal dysfunction is often attributed to orchiectomy and gonadotoxic therapy, yet semen and hormonal abnormalities may already be present at diagnosis. This narrative review synthesizes evidence obtained before orchiectomy and, where explicitly identified, broader pretreatment or pre-gonadotoxic evidence. Pre-orchiectomy studies generally report reduced sperm concentration, total sperm count, and progressive motility, together with impaired Sertoli and Leydig cell function. Tumor-derived human chorionic gonadotropin (hCG) can mask reduced Leydig reserve; in hCG-negative men, research-derived testosterone-to-luteinizing hormone and calculated free testosterone-to-luteinizing hormone ratios may aid risk stratification but lack standardized diagnostic cutoffs. Proposed contributors include testicular dysgenesis, contralateral impairment, germ cell neoplasia in situ, local tumor effects, and oxidative or proteomic alterations, although evidential support varies. These findings support fertility counseling at diagnosis, sperm cryopreservation before orchiectomy when feasible without delaying treatment, selected use of onco-microTESE when no usable ejaculate is available, and hCG-aware endocrine follow-up.