Management of the undescended testis in relation to the development of cancer.

The undescended testis carries an increased risk of cancer; however, the exact individual risk of a cryptorchist during his life to develop cancer is unknown. The risk of developing cancer can be calculated from three important figures: (a) the number of cryptorchists in the population; (b) the number of malignant testicular tumors found in undescended testicles; and (c) the number of testicular tumors per annum. In the literature, a 48 times increased chance to develop testicular cancer is accepted; it is a high risk which is contrary to the fact that a malignant cryptorchid testis is a very rare disease. Based on the estimated risk for the cryptorchist in the Netherlands to develop testicular cancer, this article criticizes the value of the figures that are generally used to calculate the individual risk; it is concluded that even today the exact risk is unknown. In giving advice concerning the management of undescended testis, one must appreciate not only the supposed cancer risk, but also take into consideration morbidity and mortality after prophylactic orchidectomy and improved cure rates after electively treated testicular tumors.