Testicular germ cell tumors are on the rise among Hispanic adolescents and young men, a new study has shown.
From 1992 to 2000, the incidence among Hispanic whites increased 58% – significantly more than the 7% seen in the non-Hispanic white population, according to Franklin L. Chien.
The report was published in the July 14 issue of Cancer.
For the Hispanic males, this translated to an absolute increase of 4 cases/100,000 per year; the absolute increase among non-Hispanic whites was 0.81 cases/100,000 per year, wrote Mr. Chien of Seattle Children’s Hospital, Washington, and his coauthors (Cancer 2014 July 14 [doi:10.1002/cncr.28684]).
The authors extracted their data from the U.S. Surveillance, Epidemiology, and End Results (SEER) database. During 1992-2010, there were 18,545 first diagnoses of testicular germ cell tumors (TGCT) in white males aged 15-39 years. Of these, 3,488 were Hispanic whites and 15,057, non-Hispanic whites.
While TGCT is still significantly more common among non-Hispanic whites, that incidence plateaued over the 19-year study period, with an absolute change of about 1%. In contrast, the annual change for Hispanic males was 3.6 %. This increase affected every 5-year age group from 15 to 39 years, and was present for both seminoma and nonseminoma subtypes.
An analysis of a shorter time span (2000-2010) had essentially the same findings: an annual change of 0.24% for non-Hispanic whites vs. 3.8% for Hispanic whites.
The reasons behind the increase are unclear, the researchers noted. It could be due in part to a more explicit classification of "Hispanic" in the census, but if that were the case, a corresponding rise in other cancers should also have been obvious, they wrote.
TGCT has been linked to environmental factors, including exposure to polyvinylchloride, pesticides, and agricultural work. Marijuana also has been implicated. The authors noted that, compared with blacks and non-Hispanic whites, Hispanic whites are the most likely to use the drug (50% of Hispanic teens compared with 40% of black and 35% of non-Hispanic white teens).
However, "because marijuana use has increased among both Hispanic and non-Hispanic whites, and because the incidence of both seminoma and nonseminoma TGCT rose ... marijuana use alone does not adequately explain the observed increase ..."
The study was funded by the Seattle Children’s Guild Association Teen Cancer Grant. None of the authors had any financial disclosures.