June 1st 2005Anne McTiernan has provideda comprehensive and balancedreview of a complex topic,namely, “Obesity and Cancer: TheRisks, Science, and Potential ManagementStrategies.” The impressiveweight of assembled evidence from thecited observational studies has been sufficientto influence several cancer organizations,including the AmericanCancer Society and the American Institutefor Cancer Prevention, to issuerecommendations regarding nutritionand physical activity in relationship tocancer.[1,2] However, clinical practiceis unlikely to undergo substantialchange in the absence of prospectivetrials demonstrating benefit on clinicaloutcomes.[3] For at least the breast cancerand obesity question, informationfrom phase III randomized, prospectiveclinical trials evaluating lifestyleintervention influence on clinical outcomeare anticipated in the near future.