Re: television viewing and time spent sedentary in relation to cancer risk: a meta-analysis.

We read with great interest the systematic review and meta-analysis by Schmid et al. on time spent sedentary and risk of cancer (1). Comparing the highest vs lowest levels of sedentary time, prolonged time spent in sedentary pursuits is associated with increased risks of colon, endometrial, and lung cancer, but not with other types of cancers, including breast cancer. This is a very important and timely investigation considering the high prevalence of sedentary behavior and the high and increasing burden of cancer worldwide (2). Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among women worldwide (2). Although no association was found between sedentary behavior and risk of breast cancer, combining the results of risk of breast CoRReSpondenCe