Is there a dose-response relationship between physical activity and breast cancer risk?
A dose-response relationship between physical activity and breast cancer risk reduction was confirmed by most of the studies that investigated this connection. A dose-response relationship means that the more active women were, the greater the reduction in breast cancer risk. This type of relationship is considered an important piece of supportive evidence. It not only provides evidence for a potential cause and effect association between physical activity and decreased breast cancer risk, but it also helps define the amount of physical activity necessary for a substantial risk reduction. A task force of the Dutch Cancer Society recently evaluated the relationship between hours of physical activity per week and breast cancer risk. Using the results from seventeen case-control studies they found a statistically reliable six percent decrease in breast cancer risk for each additional hour of physical activity per week. The analysis assumed that the activity was continued throughout a woma
