The relationship of physical activity to risk of testicular cancer

grantor: University of TorontoTesticular cancer is the most common cancer among Ontario males aged 25-34, yet few studies have examined the relationship between modifiable factors and testicular cancer risk. Data collected as part of the Enhanced Cancer Surveillance Study were used to examine the relationship between recreational and occupational physical activity at various life periods, including lifetime activity, and risk of testicular cancer. Analysis of 212 cases and 251 controls revealed that relatively high frequency of participation (greater than five times a week) in moderate and strenuous recreational activity in one's mid-teens may have an adverse effect on risk of testicular cancer; moderate or strenuous occupational demands in one's 20's also increased risk of disease. Little difference was seen in the magnitude or significance of the odds ratios between analyses of moderate and strenuous activity separately or between our analyses of total recreational activity, one of which assumed equivalency of moderate and strenuous activity and one of which assigned weights based broadly on MET values. It would appear, then, that it is the frequency of activity at adolescence that is the relevant measure. Increased exposure to androgens as a result of relatively high frequency of participation in physical activity, at a critical period of hormonal balance, may be responsible for the observed adverse effects.M.Sc