Management of testicular intraepithelial neoplasia (TIN) - a review on thefoundation of evidence based medicine (EBM)

Testicular intraepithelial neoplasia (TIN; also called carcinoma in situ of the testis) is the uniform precursor of testicular germ cell tumors. There is general agreement on the biological significance of TIN, however, the t reatment is still a matter of dispute. The present review summarizes the tr eatment options currently available. In general, the management of TIN has to be adapted to the particular clini cal situation of the patient. Eradication of TIN usually implies the loss of fertility. Therefore, fertil ity aspects should be considered before any kind of treatment is employed. Usually, patients with TIN have only small residual potential of fertility. Nonetheless, individual patients may qualify for sperm banking or cryopres ervation of testicular tissue for future sperm extraction (TESE) and assist ed fertilization. The most common clinical situation is the case of contralateral TIN in the presence of unilateral testicular cancer. Low dose radiotherapy to the test is with 18 Gy is the standard management option in these patients. The same procedure may be applied to solitary testicles after partial orchiectomy f or germ cell tumors. During followup, testosterone levels should be evaluat ed every six months. If chemotherapy is required due to metastatic disease of the primary tumor management of TIN should be deferred. After chemotherapy 30% of TIN cases w ill persist and approximately 42% will recur in the later course. Repeat bi opsy should be done six months after completion of chemotherapy or later. O nly in cases with persistent TIN additional radiotherapy should be administ ered. If one testicle is afflicted with TIN while the other testis is in healthy condition (conceivable in infertility cases or patients with primary extrag onadal germ cell tumors), then the TIN-bearing testis should be excised. Ra diotherapy is not feasible in these cases because of shielding problems wit h the healthy testis.