Objective: Several, but not all, studies have observed increased risks of testicular germ cell cancer (TGCC) associated with bicycling and other recreational activities. To further examine whether physical activity (PA) in adolescence is associated with TGCC risk, the authors conducted a case-control study in western Washington State.
Methods: Cases (n = 391) were men diagnosed with TGCC, who were identified through a population-based cancer registry. Controls (n = 1,023) were men identified from the general population in western Washington State by using random digit telephone dialing. Participants were queried about various specific PA in grades 7-12 including bicycling, horseback riding, competitive sports, physical education class, as well as moderate, vigorous, and sedentary activities in general.
Results: In multivariate analyses, bicycling, vigorous-intensity activities, and sedentary activities were not associated with TGCC risk, while horseback riding and wrestling were associated with decreased risks, and moderate-intensity activities, soccer, basketball, and intermediate duration of competitive activities were associated with increased risks.
Conclusions: The lack of internal consistency of the findings within the current study and of findings among prior studies suggests that PA contributes little, if any, to the risk of TGCC.