title: Birth weight and the risk of testicular cancer: a meta-analysis.
abstract: The high incidence of testicular cancer in young males indicates a potential role of events during early life. Birth weight has been identified as a factor possibly associated with the risk of cancers later in life. To investigate the association between birth weight and testicular cancer, we conducted a Systematic Review and Meta-Analysis of published studies investigating the association between birth weight and testicular cancer. Data were combined using a fixed-effects model. 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.
authors.affiliation: Children's Hospital, Harvard Medical School, Boston, MA, USA. athanmic@yahoo.com
authors.forename: Athanasios
authors.initials: A
authors.lastname: Michos
authors.forename: Fei
authors.initials: F
authors.lastname: Xue
authors.forename: Karin B
authors.initials: KB
authors.lastname: Michels
mesh_terms: D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D012307:Risk Factors; D013736:Testicular Neoplasms / Q000453:epidemiology*