Birth weight and the risk of testicular cancer: A meta-analysis

Thirteen epidemiologic studies, published between 1983 and 2004, were included in the analysis, encompassing 5,663 patients with testicular cancer. Men weighing less than 2,500 grams at birth had a higher risk for developing testicular cancer later in life than those with normal birth weight (2,500-4,000 g) (OR = 1.18; 95% confidence interval (CI) 1.01-1.38). A similar trend was found for men with a birth weight above 4,000 g, (OR = 1.12; 95% CI 1.02-1.22). When seminoma and nonseminoma testicular cancer cases were considered separately, low birth weight was a risk factor specifically for seminomas (OR = 1.44; 95% CI 1.11-1.88). A U-shaped association was observed between birth weight and the risk for testicular cancer. The underlying biological mechanisms for this phenomenon remain to be elucidated.