Epidemiology is the study of the distribution and determinants of disease, including factors related to disease incidence, morbidity and survival. Numerous Fred Hutch researchers are working to advance our knowledge of the epidemiology of cancer and other diseases so we can identify and refine prevention strategies and improve survival rates.
Much of our research into the origins of cancer takes place within the Epidemiology Program in our Public Health Sciences Division. Our epidemiology studies use large patient groups, or cohorts, and clinical trials to look for patterns relating to the development or prevention of disease. Cohorts coordinated by Fred Hutch include that of the Women’s Health Initiative (WHI), which enrolled over 160,000 postmenopausal women in the early 1990s and studied them for more than a decade; the Vitamins and Lifestyle (VITAL) Study, which enrolled over 77,000 older adults to learn about dietary supplements and cancer risk; and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), with data from more than 40,000 participants. Many studies have included patients identified through the Fred Hutch-based Cancer Surveillance System, which is part of the National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) Program, a national registry of cancer incidence and survival.
Poor diet, lack of exercise, obesity and tobacco use are among the many lifestyle factors that have been associated with incidence of cancer and other diseases. Our scientists have made important contributions to this body of knowledge. For example, Fred Hutch clinical trials have shown that weight loss and exercise are linked to improvements in several breast and colon cancer risk factors. Other studies at Fred Hutch have found associations between increased body weight and increased risk of developing cancer and poorer survival rates among people with cancer.
Other diseases that affect cancer risk — including diabetes, viral or bacterial infection, and treatment for an earlier cancer or other disease — are a rich area of investigation at Fred Hutch. Among the many significant findings that have emerged from the long-term Women’s Health Initiative, for which Fred Hutch serves as the coordinating hub, is the link between the use of combination hormone replacement therapy and an increased risk of lobular breast cancer. Fred Hutch is also the site of important epidemiological work on HIV/AIDS. In one study, our investigators found that seven species of vaginal bacteria, when present in high concentrations, may significantly increase the risk of HIV infection in women.
Fred Hutch researchers have been pioneers in understanding the genetic risks of cancer and other diseases. This includes important work on the breast cancer susceptibility genes BRCA1 and BRCA2 and genetic risk factors for many other cancers as well as heart disease, obesity, diabetes, inflammation, dementia and other conditions. For example, one study identified 40 new genetic variants, beyond the 55 previously identified, that signal an increased risk of colon cancer. Other discoveries include a common genetic variant that appears to significantly increase the risk of colorectal cancer from the consumption of processed meat, and a genetic variant in African-American women that is a marker of inflammation linked to increased risk of heart disease, diabetes and some cancers.
A number of Fred Hutch researchers are investigating the factors behind cancer recurrence and the risks of being diagnosed with a second cancer. Examples include the Prostate Cancer Active Lifestyle Study (PALS), which aims to learn whether weight loss through diet and exercise can improve the health of men with low-grade prostate cancer under active surveillance, and a study of factors affecting the survival of young breast cancer patients. Past studies have examined how factors such as coffee consumption and moderate alcohol affect rates of cancer recurrence.