Half-life of serum alpha-fetoprotein in prepubertal testicular yolk sac tumors: an index significantly associated with prognosis.

ABSTRACT

PURPOSE: To evaluate the association between serum alpha-fetoprotein (AFP) half-life (HL) and prognosis in prepubertal children with elevated AFP values 3 to 4 weeks after surgery for testicular yolk sac tumors (YST). METHODS: Prepubertal patients with testicular YST treated with radical orchiectomy between January 2016 and December 2022 were retrospectively reviewed. Negative outcomes were defined as relapse, metastasis or death. Univariate and multivariate logistic regression analyses were conducted to select risk factors for negative outcomes. RESULTS: A total of 42 patients were eventually enrolled into the study. Patients were divided into non-negative and negative outcomes groups, consisting of 35 and 7 patients, respectively. Thirty-five patients were stage I, two cases were stage II, and five cases were stage IV, according to the Children's Oncology Group staging system. The overall survival (OS) rate was 100%. Average AFP values significantly decreased after resection (P < 0.001). A significant positive correlation was shown between pre- and postoperative AFP values (r = 0.60, P < 0.001). Long AFP HL was considered as an independent risk factor for negative outcomes in YST patients underwent radical orchiectomy (P = 0.04). The cut-off value for AFP HL was 5.78 days, regardless of age division. CONCLUSION: Testicular YST is a relatively rare disease in children with an OS of 100%, and salvage chemotherapy is effective even in grade IV patients. The postoperative AFP HL was significantly associated with prognosis in prepubertal patients with testicular YST. The cut-off value for AFP HL is 5.78 days regardless of the effect of physiological AFP elevation.