Current Treatment Patterns and Outcomes of Sex Cord Stromal Tumor Patients in Japan

Sex cord-stromal tumors (SCSTs) constitute approximately 5% of testicular malignancies. This investigation aimed to elucidate contemporary therapeutic approaches and clinical outcomes for patients with testicular SCSTs in Japan.

Participating institutions included Japan Clinical Oncology Group facilities, affiliated centers, and institutions with published cases. Clinical data and histopathological findings were compiled. Central pathological review involved representative tissue sections when available. Kaplan-Meier methodology assessed recurrence-free survival (RFS) and overall survival (OS). Stage I patients were stratified by cumulative pathological risk factors (tumor diameter ≥ 5 cm, necrosis, moderate to severe nuclear atypia, lymphovascular invasion, infiltrative growth, and ≥ 3 mitoses per 10 high-power fields).

Among 116 patients from 66 institutions, 112 met inclusion criteria. Histological distribution included Leydig cell (n = 54), Sertoli cell (n = 36), and other variants (n = 22). Twelve patients presented with metastatic disease; ten received systemic chemotherapy, with 20.8% five-year OS. Among 91 stage I patients with follow-up data, eleven developed recurrence. Patients with > 2 risk factors demonstrated significantly inferior RFS compared with those showing ≤ 1 factor (26.4 versus 98.6% at 5 years, p < 0.0001). Surgical intervention predominated in the recurrent cases (81.8%, 9/11), while chemotherapy was administered to 45.5% (5/11), and selected patients achieved prolonged disease control through repeated surgical resection without systemic therapy. OS rates were 90.9% and 50.5% at 5 and 10 years.

Patients with synchronous metastatic presentation demonstrated poor survival. Stage I patients with > 2 pathological risk factors showed reduced RFS, with surgical management potentially efficacious for recurrent disease.