Plateau in testicular cancer incidence in some parts of the United States (US) especially among non-Hispanic white males in Los Angeles had been observed. We conducted three decades temporal trends analysis to assess the evidence of such a plateau, and to examine whether the rate remains stable across racial/ethnic groups as well as the influence of age at diagnosis on the incidence rate.
Population-based temporal trends analysis.
Using the Surveillance Epidemiology and End Results (SEER), we identified between 1975 and 2004, 16,580 of newly diagnosed testicular cancer cases, aged 15−49 years. The incidence rates were examined by calculating the age-adjusted rates and their 95% Confidence Interval (CI) for the age at diagnosis, SEER areas, and race by the year of diagnosis. The percent change and annual percent change were examined for trends.
Incidence of testicular cancer continues to increase among US males, albeit the plateau of the 1990s. Between 1975 and 2004 the age-adjusted incidence rate for ages, 15−49 years increased from 2.9 (1975) to 5.1(2004) per 100,000. The trends indicated a percent change of 71.9% and a statistically significant annual percent change of 1.6 %,( 95% CI, 1.3−2.0), p < 0.05. Though the rates in blacks remained strikingly low, 0.3 to 1.4 per 100,000, the highest annual percent change was observed among blacks, 2.3%, (95%, CI, 0.8−3.9), p < 0.05 for trends. The rates were intermediate among Asians/ Pacific Islanders and American Indian and Alaska Natives 0.7 to 2.9 per 100,000, percent change (117.3%) and a statistically significant annual change of 1.5%, (95% CI, 0.3−2.7) p < 0.05 for trends. The highest rates were reported among Whites, 3.2 to 6.3 per 100,000, percent change (90.4%) , with a statistically significant annual percent change of 2.0%, (95% CI, 1.6−2.3), p < 0.05. The peak age at diagnosis was, 30−34 years while the lowest rates were reported in 15−19 age group. Likewise, incidence rates varied by SEER areas with predominantly white states representing areas associated the highest reported rates.
Overall, testicular cancer incidence rate remains to plateau in the United States, while racial variance persists in rates, black males demonstrated the highest increase in the annual percent change. Further studies are needed to examine the recent increase among black males and the potential determinants.