by Jennifer K. Loukissas, M.P.P.
Along the Andes mountain range, through Central America, and in many other regions of the world, gastric cancer is a leading cause of death. For one DCEG researcher, the study of this malignancy is a passion, and the primary cause for most gastric tumors—chronic Helicobacter pylori infection—is the subject of her ambitious research agenda. Maria Constanza Camargo, Ph.D., newly-appointed Earl Stadtman Investigator in the Metabolic Epidemiology Branch (MEB), knew from the start she wanted to work on gastric cancer.
“I breathe gastric cancer,” she said, describing her passion for this work. Of the critical importance of this public health challenge, she was clear: “We have to do something.”
It was a circuitous path—both personally and scientifically—that brought her to the Division, starting from her home in Colombia, to graduate studies in Cuernavaca (Mexico), New Orleans and Chicago. In 2005, her research was interrupted when she and everyone else in the lab was displaced by Hurricane Katrina. But she was steadfast in her goal to tackle the pressing questions for this malignancy: If H. pylori is the causal factor, why do about 1% of those with chronic infection go on to develop disease? What cofactors drive carcinogenesis? How can we identify those at highest risk, who can most benefit from intervention or surveillance?
Dr. Camargo first came to DCEG in 2008 as a summer student. She returned the following summer and accepted a postdoctoral fellowship in the Infections and Immunoepidemiology Branch (IIB) upon completion of her degree in 2010. Since that time she has set her sights on the complex problems of gastric cancer etiology and prevention. To do so, she has developed a robust research program and a dynamic and multidisciplinary team to apply cutting edge molecular epidemiological approaches to the study of H. pylori, precursor lesions, and the natural history of gastric cancer.
In general, survival of patients with gastric cancer is poor, mainly because of advanced-stage at diagnosis. There are ample opportunities for early intervention since gastric cancer develops over decades and advanced precancerous lesions can be cured by endoscopic resection (or less invasive surgical treatment). But without appropriate screening strategies it is impossible to know who is most at risk. The potential benefit of H. pylori eradication to prevent gastric cancer is highly suggested by some randomized trials in high-risk areas. However, there is insufficient evidence to justify large-scale implementation.
To collect the samples necessary to carry out her work, Dr. Camargo is working collaboratively with Charles Rabkin, M.D., and other researchers around the globe, to build the first biobank of H. pylori clinical isolates and a case-control study to elucidate the risk factors for advanced pre-neoplastic lesions in a high-risk population, and potential non-invasive biomarkers for risk stratification.
As a smaller research effort, Dr. Camargo is collaborating with Sanford Dawsey, M.D., and MEB Branch Chief Christian Abnet, Ph.D., to design and conduct molecular epidemiologic studies of esophageal squamous cell carcinoma (ESCC), another malignancy for which etiologic factors are few, and which may also be influenced by infections. Smoking and alcohol consumption are the major risk factors for ESCC in Western populations, but they are not strongly associated with disease in endemic Asian populations.
With tissue, blood and urine samples from previous ESCC studies waiting in the DCEG freezers, Dr. Camargo is poised to examine the relationship of this malignancy and its precursors with viral and bacterial infections and various molecular and immuno-related biomarkers. This broad approach is intended to identify a panel of biomarkers that may one day evolve to a highly predictive screening tool.
Named after Earl Stadtman, a noted biochemist at the National Heart, Lung, and Blood Institute, the Stadtman program is a trans-NIH recruitment initiative designed to attract the most talented early-career scientists to NIH.