Patients with bulky metastatic non-alpha-fetoprotein-producing seminomas were eligible for this phase II study [serum human chorionic gonadotropin < 200 U l-1 (< 40 ng l-1)] if they presented with abdominal masses > or = 10 cm or had extra-gonadal seminoma or had relapsed after previous radiotherapy. This evidence concerns the gene AFP and extragonadal seminoma.