International patterns and trends in testis cancer incidence

Although the incidence of testis cancer has risen markedly in many Western populations over the past half-century, it is not clear whether rates in other populations also have increased. To clarify this issue, we examined testis cancer incidence rates over the 25-year time period of 1973-1997 for selected populations around the world. Age-standardized incidence rates for 21 registries in the Americas, Asia, Europe and Oceania over successive 5-year time periods were obtained from volumes 4-8 of Cancer Incidence in Five Continents. Testis cancer rates rose between 1973 and 1997 in most populations worldwide, although the increases were strongest and most consistent among populations of European ancestry. Rates appear to be leveling off in some populations. The increases in testis cancer remain unexplained, although changes in the prevalence of important risk factors for this disease may be responsible.