Trends in testicular germ cell tumours by ethnic group in the United States

Abstract

The incidence of testicular germ cell tumours (TGCT) has increased in white and black men in the United States. Little is known, however, about trends among men of other racial/ethnic groups. The current study sought to examine TGCT patterns among men of Asian/Pacific Islander/American Indian/ Alaska Native (API/AIAN) and Hispanic ancestries and to determine whether tumours in these groups are diagnosed at comparable stages and sizes to tumours in white and black men. TGCT incidence data and tumour characteristics were drawn from the Surveillance, Epidemiology and End Results registries for two time periods: 1973-2003 and 1992-2003. In 1973-2003, TGCT rates were significantly lower among black (rate ratio = 0.18, p < 0.001) and API/AIAN (rate ratio = 0.37, p < 0.001) men than among white men. Among white and API/AIAN men, rates increased over 60%, mainly prior to 1989-1993. Among black men, rates increased almost 40%, mainly after 1989-1993. Among white and API/AIAN men, increasing proportions of localized disease were diagnosed over time, while the opposite trend was seen among black men. In 1992-2003, TGCT incidence among Hispanic white men (3.46/100 000) was significantly lower than it was among non-Hispanic white men, but rates of both seminoma and non-seminoma increased. While the incidence of TGCT increased among all men, different patterns in the increase were evident. These data suggest that rates are increasing among Hispanic white men and black men, but are stabilizing among white men and API/AIAN men. The peak of the TGCT epidemic may have been reached in these latter groups.