The value of the biopsy of the contralateral testis in patients with testicular germ cell cancer: The recent German experience

Purpose: Testicular intraepithelial neoplasia (TIN; so-called carcinoma in situ of the testis), the precursor of testicular germ cell neoplasms can be detected by testicular biopsy many years before the clinical manifestation of the tumour. This study looked at the prevalence of contralateral TIN in patients with testicular germ cell cancer. The purpose was to evaluate this new approach of early detection of testicular cancer and to evaluate the current management strategies. Patients, methods: 1954 consecutive patients with unilateral testicular germ cell tumour underwent contralateral biopsy. All specimens were examined immunohistologically with staining for placental alkaline phosphatase. Patients with TIN were usually submitted to low-dose radiotherapy of the testis. A rebiopsy was performed after 3 months. Endocrinological evaluations were done before, during and after treatment. Results: TIN was observed in 4.9% (95% confidence intervals 3.95% - 5.91%). Testicular atrophy constitutes a 4.3 fold increased risk of having contralateral TIN. 64% of the cases with TIN were found in clinically normal testes. Patients with TIN were significantly younger than those without (p<0.017). No case with TIN was found in patients older than 50 years. Three patients developed a second testicular tumour during follow-up despite a negative biopsy. After radiotherapy, all of 23 patients had complete disappearance of TIN in the rebiopsy. After chemotherapy, 3 of 10 patients had persistent TIN histologically. After radiotherapy, 12 of 41 patients required testosterone replacement. Conclusion: The prevalence of contralateral TIN accords well with the known prevalence of bilateral testicular tumours. Testicular atrophy is a strong indicator for the presence of TIN but about 60% of TIN-cases occur without atrophy. Local radiotherapy to the testis with 18 - 20 Gy is efficaceous in eradicating TIN, but it causes significant damage to almost one quarter of these patients. Chemotherapy is an unsafe treatment for TIN. This study shows the feasibility of early detection of testicular cancer in a high-risk population by means of searching for TIN. Although the management of the condition still needs refinement, the TIN-concept offers an avenue for the early detection of testicular cancer and early conservative management.