Cancer epidemiology: researchers take a broader approach

Elizabeth Platz at 2012 Johns Hopkins Nano-Bio Symposium. Photo by Stephanie Fraley

“Where do cancer data even come from?” This was the question posed to Dr. Elizabeth Platz prior to the 2012 Johns Hopkins University Nano-Bio Symposium. Dr. Platz is the Martin D. Abeloff, MD Scholar in Cancer Prevention and director of the Cancer Epidemiology, Prevention, & Control Training Program at the Johns Hopkins Bloomberg School of Public Health. As a cancer epidemiologist, Platz studies the frequency, distribution, and causes of cancer using data collected by the National Cancer Institute. By looking at these data, epidemiologists hope to understand why cancer occurs and what might be done to prevent it. “Cancer mortality in the US is declining and has been for some time,” Platz said. “The question is why.”

Dr. Platz and other cancer epidemiologists work on answering this “why.” Platz explained that cancer epidemiologists hypothesize why cancer rates may be high in certain segments of the population, follow a cohort of at-risk patients to see if they develop disease, and then try to figure out if some risk factor could be partially responsible for the disease. By identifying risk factors, cancer epidemiologists can influence public policy and promote preventative action.

Increasingly, cancer epidemiologists are working with researchers trying to answer basic science questions. An example of Dr. Platz’s recent interdisciplinary work involves finding tissue-based markers for prostate cancer, which could inform diagnoses and treatment decisions made by clinicians. One potential marker the researchers found is telomere length. Telomeres are repeated units on the ends of all chromosomes. Platz and her team of collaborators at Johns Hopkins showed that variability in tumor cell telomere length gave a 40-times greater risk for recurrence when compared with low telomere length variability. In the future, telomere length may be quantified following removal of a patient’s primary tumor before deciding on the next course of treatment.

Dr. Platz finished her talk by discussing the importance of having scientists in the nanobiotechnology fields work with cancer epidemiologists. Nanobiotechnology could greatly help epidemiologists measure exposure to environmental toxins and handle large amounts of data, allowing the epidemiologists to better make and test hypotheses about why cancer occurs. Future collaborations have the potential to drastically improve cancer care and patient survival rates.

Story by Colin Paul, a Ph.D. student in the Department of Chemical and Biomolecular Engineering at Johns Hopkins with interests in microfabrication and cancer metastasis.