Armen Ghazarian, MPH Cancer Research Training Award Fellow, National Cancer Institute
Testicular germ cell tumors (TGCT) are the most commonly occurring malignancy among young men in the United States. As with most populations around the world, the incidence of TGCT is higher among white men than men of other racial/ethnic groups. A National Cancer Institute study team used NAACCR Cancer in North America (CiNA) data to forecast trends in testicular cancer incidence by race/ethnicity and by histologic subtype (seminoma, nonseminoma). They found that while TGCT incidence remains highest among white men, rates are increasing most rapidly among Hispanic men. Within the next decade, TGCT incidence rates among Hispanic men are expected to surpass the rates among white men because of increases in both seminoma and nonseminoma. Reasons for the increase among Hispanics are unclear, but could possibly be related to place of birth, unidentified environmental exposures, country of ancestry, and/or length of residence in the United States according to Armen Ghazarian, one of the study authors.
Abstract
Background
Testicular germ cell tumors (TGCTs) are rare tumors in the general population but are the most commonly occurring malignancy among males between ages 15 and 44 years in the United States (US). Although non-Hispanic whites (NHWs) have the highest incidence in the US, rates among Hispanics have increased the most in recent years. To forecast what these incidence rates may be in the future, an analysis of TGCT incidence in the Surveillance, Epidemiology, and End Results program and the National Pro-gram of Cancer Registries was conducted.
Methods
TGCT incidence data among males ages 15 to 59 years for the years 1999 to 2012 were obtained from 39 US cancer registries. Incidence rates through 2026 were forecast using age-period-cohort models strati-fied by race/ethnicity, histology (seminoma, nonseminoma), and age.
Results
Between 1999 and 2012, TGCT incidence rates, both overall and by histology, were highest among NHWs, followed by Hispanics, Asian/Pacific Islanders, and non-Hispanic blacks. Between 2013 and 2026, rates among Hispanics were forecast to increase annually by 3.96% (95% confidence interval, 3.88%-4.03%), resulting in the highest rate of increase of any racial/ethnic group. By 2026, the highest TGCT rates in the US will be among Hispanics because of increases in both seminomas and nonseminomas. Rates among NHWs will slightly increase, whereas rates among other groups will slightly decrease.
Conclusion
By 2026, Hispanics will have the highest rate of TGCT of any racial/ethnic group in the US because of the rising incidence among recent birth cohorts. Reasons for the increase in younger Hispanics merit further exploration. Cancer 2017;000:000-000. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
Keywords
Incidence, ethnic groups, North American Association of Central Cancer Registries (NAACCR), testicular cancer, testicu-lar gem cell tumor (TGCT), trends.
The opinions expressed in this article are those of the authors and may not represent the official positions of NAACCR.
