(RxWiki News) One sector of young American males is seeing more testicular cancer now than ever, and experts don’t know why.
A new study found that the rate of testicular cancer has grown fastest among young Hispanic white men.
Hispanic white men are those who live in the United States but were born in a Spanish-speaking country or have ancestors who were.
"Visit your doctor if you notice a lump in your testicles."
Rebecca Johnson, MD, of Seattle Children’s Hospital, led this study.
Dr. Johnson and colleagues looked at two data sets from the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) Program. The first set of data came from 1992 to 2010 and involved 15 percent of the population of the United States. The second set of data covered 2000 to 2010, and included data from 28 percent of the American population.
Testicular germ cell tumors (TGCT) are the most common solid cancers among adolescent and young men, accounting for 21 percent of tumors in this age group.
The men in this study population were 15 to 39 years of age.
The researchers found that for the first set of data, the rate of TGCT had increased by 58 percent among Hispanic white young men, from 7.18 cases per 100,000 in 1992 to 11.34 cases per 100,000 in 2010. Among non-Hispanic white men, the rate only rose by 7 percent (12.41 to 13.22 per 100,000 cases).
In looking at the 2000 to 2010 interval, the researchers observed no significant trends in incidence among non-Hispanic whites. However, the rise in incidence for Hispanic whites was similar to that found in the first set of data.
The researchers considered various possible reasons for this trend. One such reason may be an improvement in the classification of Hispanic. There has been tremendous growth of Hispanics in the United States, and initially, people of Mexican descent, Puerto Rican descent or subgroups from Central and South America may not have been counted, the researchers explained. However, if this was the reason for the difference, there should be a similar rise in cancers of all kinds among the Hispanic population, and this hasn’t been the case, the researchers wrote.
Dr. Johnson and team also considered risk factors for testicular cancer, which include height, undescended testicles, family history and a patient’s own history of TGCT. None of these fully explained the rise in incidence among Hispanic men.
These researchers also looked at marijuana use, but they found that this factor alone did not explain the rise in incidence of TGCT among Hispanic men.
The study's authors concluded that if the present trend continues, the rate of TGCT among Hispanic whites may overtake that among non-Hispanic whites.
These authors called more for research on this topic.
“Although the percentage increase in testicular cancer cases reportedly grew by 58 percent from 1992 to 2010, we shouldn’t get too alarmed by this as the actual number of cases is extremely small,” said Brian Lawenda, MD, National Director of Integrative Oncology and Cancer Survivorship at 21st Century Oncology in Las Vegas, Nevada.
"If you look at the statistics you will see that there were only 7.18 cases per 100,000 population in 1992 and 11.34 cases per 100,000 in 2010. That’s an increase of 4.16 total cases per 100,000 population, which translates into a minuscule absolute increase of only 0.00416 percentage points," he said.
Dr. Lawenda told dailyRx News that he is not convinced there is a trend. “Although the authors found that this reached statistical significance, I am not convinced that an increase of approximately four new diagnoses per 100,000 is not just due to a random variation in accounting of new cases. I certainly think we need to keep an eye on this, but I would not jump to any conclusions at this time," he said.
This study was published online in July in the journal Cancer.
The authors did not disclose any conflicts of interest.