Charles E. Matthews, Ph.D.

Charles E. Matthews, Ph.D., studies the relationship between physical activity behaviors and the development of cancer in humans. In etiologic studies, he seeks to understand how the full spectrum of physical activity behaviors influences cancer risk, the dose-response relations between active and sedentary behaviors and cancer, and the biological mechanisms underlying these relationships. In his methodological research, he is working to develop better methods and tools for measuring physical activity behaviors in population-based studies. This knowledge is critical to the development of evidence-based public health guidelines for physical activity and cancer prevention and control.

Cancer Etiology Research

Dr. Matthews and colleagues conduct research that adds to the evidence base relating both physically active and sedentary behaviors to risk for developing cancer, as well as prognosis following a cancer diagnosis. For several types of cancer, research has shown the benefits of moderate-to-vigorous physical activity to reduce risk. However, our understanding of amount of activity required to achieve risk reduction, the potential benefits of lower intensity activities and the adverse effects of sedentary behaviors remains limited. For all other cancer sites where the evidence is less clear, his research seeks to test the hypothesis that physical activity is associated with reduced risk for these outcomes. In addition, recently he has begun to test the hypothesis that the duration, quality, and timing of sleep may be associated with increased risk for certain cancers. Using an integrative epidemiology framework as a guide, Dr. Matthews’s mechanistic research attempts to expand current understanding of the biological mechanisms linking physical activity behaviors and energy balance to cancer risk. He is exploring the metabolic effects that habitual patterns of physical activity and/or prolonged sedentary time may impart in adults.

Methodological Research

Dr. Matthews’s methodological research addresses the need for better tools to assess physical activity behaviors in large population-based studies. Self-reported information about active and sedentary behaviors from questionnaires that rely on long-term recall/averaging are known to be prone to measurement error. Errors in these exposure assessments may limit our ability to find important physical activity-cancer associations, and to describe the true dose-response relationships for the associations that we can detect. Dr. Matthews’s work in this area includes the description of the measurement error structure of existing self-report instruments. He has developed and tested a novel internet-based previous-day recall tool, Activities Completed over Time in 24 hours (ACT24), that is freely available for use by researchers. He is also working to develop infrastructure to support advanced activity monitoring technology in large cancer etiology studies.

Dr. Matthews is a physical activity epidemiologist and senior investigator in the Metabolic Epidemiology Branch. He received a M.S. in exercise science from the University of South Carolina, Columbia, and a Ph.D. in epidemiology from the University of Massachusetts, Amherst. Dr. Matthews held academic appointments in the Department of Epidemiology and Biostatistics at the University of South Carolina and the Vanderbilt University School of Medicine prior to joining DCEG in 2009 as a tenure-track investigator; he was awarded scientific tenure by the NIH in 2016. Dr. Matthews is a Fellow of the American College of Sports Medicine (ACSM) and an Associate Editor for the ACSM journal, Medicine and Science in Sports and Exercise.