Treatment of testicular intraepithelial neoplasia (intratubular germ cell neoplasia unspecified) with local radiotherapy or with platinum-based chemotherapy: A survey of the German Testicular Cancer Study Group

Background: The treatment of testicular intraepithelial neoplasia (TIN), the progenitor of testicular germ cell tumours (GCTs), is based on little data. Patients and methods: Two hundred and twenty-eight GCT patients with contralateral TIN were retrospectively enrolled. Ten had surveillance, 122 radiotherapy to testis with 18-20 Gy, 30 cisplatin-based chemotherapy (two cycles), 51 chemotherapy (three cycles), and 15 carboplatin. The study end point was a malignant event (ME), defined as detection of TIN upon control biopsy or occurrence of a second GCT. The Secondary end point was hypogonadism during follow-up. Results: Numbers, proportions of ME, and median event-free survival (EFS) times were: radiotherapy N = 3, 2.5%, 11.08 years; chemotherapy (two cycles) N = 15, 50%, 3.0 years; chemotherapy (three cycles) N = 12, 23.5%, 9.83 years; carboplatin N = 10, 66%, 0.9 years; surveillance N = 5, 50%, 7.08 years. EFS is significantly different among the groups. Hypogonadism rates were in radiotherapy patients 30.8%, chemotherapy (two cycles) 13%, chemotherapy (three cycles) 17.8%, carboplatin 40%, surveillance 40%. Conclusions: Local radiotherapy is highly efficacious in curing TIN. Chemotherapy is significantly less effective and the cure rates are dose-dependent. Though hypogonadism occurs in one-third of patients, radiotherapy with 20 Gy remains the standard management of TIN.