Testicular Cancer

Testicular cancer is a rare cancer in the general population, but is the most common neoplasm among young men in many countries. It has one of the highest heritabilities of all cancer types. The vast majority of testicular cancers are germ cell tumors; thus the terms “testicular cancer” and “testicular germ cell tumors” (TGCTs) are often used interchangeably. Globally, the incidence of testicular cancer is highest among men of European ancestry and lowest among men of African and Asian ancestries. Incidence rates have been increasing in many countries since at least the mid-twentieth century. Mortality rates, however, have sharply declined in developed countries. While the reason for the decline in mortality rates is well known, reasons for the increase in incidence remain poorly understood. Accumulating evidence supports the hypothesis that most TGCTs are linked to disturbed development of the testes, beginning in utero, but fostered by postnatal events.