Relation of physical activity to risk of testicular cancer.

In North America and most Western European countries, testicular cancer is often cited as the most common cancer among young and middle-aged men, and yet few studies have examined the relation between modifiable factors and testicular cancer risk. Data collected between 1995 and 1996 in Ontario, Canada, as part of the Enhanced Cancer Surveillance Study were used to examine the relation between the frequency of recreational, and intensity of occupational, physical activity at various life periods, including cumulative and averaged lifetime activity and risk of testicular cancer. Analysis of 212 cases and 251 controls revealed that relatively high frequency of participation in moderate and strenuous recreational activity in the midteens may have an adverse effect on risk of testicular cancer (odds ratio = 2.36, 95% confidence interval: 1.20, 4.64 for moderate activity of greater than five times a week compared with three times or less a month and odds ratio = 2.58, 95% confidence interval: 1.14, 5.85 for strenuous activity of greater than five times a week compared with less than once a month). Moderate or strenuous occupational demands in one's 20s also increased risk of disease.