About 5% of all patients with unilateral
testis cancer harbor testicular intraepithelial
neoplasia (
TIN) in their contralateral testicle, which will progress into an invasive
germ-cell tumor over time. Accurate diagnosis of
TIN by a random surgical testis biopsy examination and effective
therapy by local radiation has led to the concept of a contralateral screening biopsy procedure in all
testis cancer patients. Screening and preventive treatment, however, only are indicated if (1) therapeutic outcome of the screened population is improved and (2) physiologic function of the affected organ might be maintained. Based on a critical review of the literature, some drawbacks of this policy have to be considered and the routine indication for contralateral testis biopsy procedure has to be questioned: (1) all
TIN-negative patients still have to undergo meticulous follow-up evaluation for metachronous
testis cancer owing to a false-negative biopsy diagnosis rate of 0.3%; (2) testis biopsy procedure is associated with a 15% to 20% complication rate, which might a negative impact on endocrine and exocrine testicular function; (3) local radiation of
TIN results in irreversible
infertility owing to eradication of spermatogenesis; (4) local radiation of
TIN results in an impairment of endocrine Leydig cell function in 25% of patients; (5) therapeutic outcome and prognosis will not be improved in irradiated patients as compared with patients on surveillance; (6) local
tumor resection for the management of metachronous
testicular cancer represents an effective and viable option. The current literature does not support the strategy to perform contralateral testis biopsy procedures in all patients with unilateral testicular
germ-cell tumors. Testis biopsy procedures might, however, be offered to high-risk (34%) patients for contralateral
TIN with a testicular volume less than 12 mL, a history of
cryptorchidism, and an age less than 30 years.