Perinatal factors and the risk of testicular germ cell tumors.

To study the etiology of TGCT, the US Servicemen's Testicular Tumor Environmental and Endocrine Determinants (STEED) case-control study enrolled participants and their mothers between 2002 and 2005. Five hundred twenty-seven mothers of cases and 561 mothers of controls provided information on perinatal variables. Logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95%CI) associated with the candidate risk factors. Analyses were conducted for all TGCT together and for each histologic subgroup (seminoma and nonseminoma) separately. Young maternal age (<20 vs. 20-29 years, OR = 1.51, 95%CI: 1.09-2.10), young paternal age (<25 vs. 25-29 years, OR = 1.45, 95%CI: 1.08-1.94), maternal parity (3 vs. 1, OR = 0.63, 95%CI: 0.44-0.90) and breech birth (OR = 1.92, 95%CI: 1.03-3.56) were associated with risk of TGCT. For seminoma, young maternal age (<20 vs. 20-29 years, OR = 1.67, 95%CI: 1.10-2.54), young paternal age (<25 vs. 25-29 years, OR = 1.53, 95%CI: 1.03-2.27), maternal parity (3 vs. 1, OR = 0.58, 95%CI: 0.35-0.96) and low birth weight (<2,500 g vs. 2,500-4,000 g, OR = 1.82, 95%CI: 1.00-3.30) were risk factors. Nonseminoma was associated with breech birth (OR = 2.44, 95%CI: 1.25-4.78) and Cesarean section (OR = 2.10, 95%CI: 1.25-3.54). These results support the hypothesis that TGCT may originate in very early life.