In October 2016, two “living legends” of DCEG presented as part of the Descriptive Epidemiology Seminar Series, convened by Meredith Shiels, Ph.D. on behalf of the Descriptive Epidemiology Working Group.
Joseph F. Fraumeni, Jr., M.D., Senior Investigator and Advisor, and Robert N. Hoover, M.D., Sc.D., Director of the Epidemiology and Biostatistics Program, delivered an inspiring retrospective on decades of groundbreaking research in descriptive epidemiology titled, “Descriptive Epidemiology: Historical Perspectives and Future Opportunities.”
Dr. Fraumeni highlighted the potential of descriptive epidemiology to generate hypotheses for use in analytic epidemiology techniques. One major tool on which he and Dr. Hoover relied heavily was cancer mortality maps. Broken down by state or county (or even further), these resources can, with enough creativity and attention to detail, yield astonishing discoveries.
Watch the video: "Descriptive Epidemiology: Historical Perspectives and Future Opportunities"
For example, a team of NCI investigators led by Debbie Winn, Ph.D., now Deputy Director of the Division of Cancer Control and Population Sciences, noticed an extremely high concentration of oral and pharynx cancer in white females in the southeastern part of the United States between 1950 and 1969. They initially considered exposures resulting from the region’s textile industry. Later, they explored snuff dipping, placing ground tobacco between the gum and cheek, which was very popular among rural Southern women at the time. A subsequent field study revealed that long-term snuff use was associated with up to a 50-fold risk of oral and pharynx cancer compared to the general population. This challenged the then-held notion that snuff was a safer alternative to cigarettes.
While such large swaths of elevated cancer rates tend to draw the eye, Drs. Fraumeni and Hoover emphasized the importance of “outliers” – small spots of high incidence or mortality in areas with otherwise low or typical rates. A map of lung cancer deaths showed a notable concentration along much of the East Coast in the 1950’s and 60’s, which was linked to the detrimental late effects of asbestos exposure among shipbuilders during World War II. Investigating smaller abnormalities of the map also yielded important results–an isolated blip of red in Montana led to the implication of a nearby copper smelter, which was exposing workers and residents to high levels of arsenic. This discovery prompted new regulatory standards to protect workers.
Time trends are also an important tool, as Dr. Fraumeni illustrated with breast cancer incidence patterns over time, and racial disparities brought to light by data from the Surveillance, Epidemiology, and End Results (SEER) program.
Dr. Hoover concluded with his view of the most promising avenues in the field. Evaluation of changes in geographical and time trends can be enhanced with the inclusion of refined disease classifications. New data resources are also valuable, such as environmental exposure patterns like air pollution that may be mapped to individual communities, even specific residences. He also spoke enthusiastically about the development of new methods for analysis of “big data” that can help investigators take on increasingly larger studies.
“The seminar was very well received by the over 200 people in attendance. We look forward to many more seminars, and for opportunities to showcase descriptive epidemiology as a tool that combines cancer surveillance and etiologic research,” said Dr. Shiels.