Risk of germ cell testicular cancer according to origin: A migrant cohort study in 1,100,000 Israeli men

Testicular cancer incidence is highest among men of northern European ancestry and lowest among men of Asian/African descent. We conducted a large-scale migrant cohort study to assess origin and migrant generation as predictors of testicular germ cell tumors (TGCTs), controlling for possible confounders. Data on 1,092,373 Jewish Israeli males, who underwent a general health examination prior to compulsory military service at ages 16-19 between the years 1967-2005, were linked to Israel National Cancer Registry to obtain incident TGCTs up to 2006. Cox proportional hazards was used to model time to event. Overall, 1,001 incident cases (534 seminoma and 467 nonseminoma) were detected during 19.2 million person-years of follow-up. Origin was a strong independent predictor of TGCTs with remarkably low incidence for North African-born (HR = 0.10, 95% CI: 0.04-0.21) and Asian-born (HR = 0.35, 0.20-0.62), while intermediate for Israeli-born of North African origin (HR = 0.48, 0.40-0.58) and Asian origin (HR = 0.56, 0.47-0.66), compared to European origin. A comparison of Israeli born of North African and Asian origin with North African and Asian-born yielded a HR of 2.31 (1.36-3.93). Significant risk factors controlled for were year of birth, years of education and height. Findings persisted when analyses were stratified by histologic subtypes of TGCTs. The findings of lower rates of TGCTs among men born in North Africa and Asia compared to European ancestry, but a steep increase in next generation migrants, particularly among the Israeli-born migrants from North Africa, provide clues to direct further research on the role of modern lifestyle and environment in the etiology of TGCTs.