May 12 2015

Macro Meet Micro: Population Health Squares Off Against Precision Medicine

Precision medicine or population health? On the face of it, the two couldn’t be further apart: one aims to tailor treatments to the few while the other works to confront disease for millions on a global scale. A recent seminar at Columbia University’s Mailman School of Public Health brought together experts from both fields to locate common ground.

In 2014, Columbia President Lee Bollinger announced a university-wide precision medicine initiative. Nearly a year later, in his State of the Union address, President Obama launched a similar effort on the federal level,  committing $214 million for research. Made possible by rapid advances around the human genome, both initiatives aim to broaden understanding around genetic variation in disease to better match patients with effective therapies.

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Wafaa El-Sadr leads discussion

The goals of population health are no less grand. Wafaa El-Sadr, who hosted the discussion, enumerated several principles, from ensuring maximum benefit for the largest number of people to intervening at multiple levels from behaviors to the environment to social conditions. Population health takes a global view, added El-Sadr, University Professor and director of ICAP and the Global Health Initiative, with special attention to disparities between haves and have-nots.

David Goldstein, director of Columbia’s Institute for Genomic Medicine, a centerpiece of the University’s Precision Medicine Initiative, said his field shares an interest in overcoming disparities. “When we reviewed them a few years ago, we found that large-scale genomic studies were being performed on individuals of European ancestry at a rate tenfold greater than all other ancestry groups put together,” Goldstein said. As a result, clinicians are significantly less able to rule out genetic factors that contribute to disease in underrepresented individuals.

Jessica Justman, associate professor of Medicine in Epidemiology and senior technical director at ICAP, proposed one avenue for collaboration involving the large-scale population surveys she currently leads in Sub-Saharan Africa that collect detailed HIV and other health information. African scientists are interested in genetic research, particularly into diseases like diabetes, tuberculosis, and sleeping sickness, added El-Sadr.
 
By one measure, population health and genetics have been with us for decades. “The largest public health program in genetics is newborn screening,” said Wendy Chung, a pediatrician and geneticist at Columbia University Medical Center. Since the early 1970s every child in the United States has been screened for genetic conditions, including metabolic disorders treatable with a modified diet. According to Chung, the next frontier is doing a similar genetic screening for adults, although she cautioned that much work is needed before such tests are ready for primetime.

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David Goldstein speaks

Limits and Possibilities

While precision medicine may play an important role in clinical medicine, does the field have what it takes to prevent illness and improve health for millions? Ronald Bayer, professor Sociomedical Sciences, proposed that the notion was “a stretch.” Major health challenges like obesity can’t be solved with genetics, he said. “People haven’t become obese because of a genetic transformation. They’re fat because they get the wrong foods.” Most global health is beyond the reach of precision medicine, Bayer added. “It’s not going to solve poverty or hunger.”

Public health too has limits, El-Sadr pointed replied. “We haven’t been able to overcome poverty and hunger either. We all need to understand our limitations.”
 
Critics of precision medicine may be reacting against overblown expectations around the Human Genome Project and now precision medicine. “The hype is a big problem here,” said Tom Maniatis, chair of Biochemistry and Molecular Biophysics and director of the University’s Precision Medicine Initiative. Nothing will change overnight, he asserted. It’s necessary to build the proper foundation to realize the field’s promise. “That’s what exciting about the Columbia Initiative: we’re building a university-wide enterprise—I don’t think anyone else is.”

Shared Purpose

Numerous opportunities exist for collaboration between public health and precision medicine. One example, said Dean Linda P. Fried, is the combined effect of genes and the environment. Added David Goldstein, “I’m convinced that there are differences among people meditated by their genomes that influence what happens to them when their environment goes bad. When the environment goes bad, it does not affect all of us equally.”

Public health will also play a role in designing and implementing population-based studies around genetics and analyzing the data, and by weighing-in on ethical questions around ownership of genetic data and ways to safeguard it. On a practical level, Mailman School faculty are already involved in shaping the new field. Dean Fried and others play a leadership role in the University initiative. In addition, the School has its own taskforce, chaired by Ken Cheung, professor of Biostatistics.

Ezra Susser, professor of Epidemiology, is engaged in research into schizophrenia in South Africa as part of a larger genomic research initiative called Human Heredity and Health for Africa (H3Africa). While genomics studies can feel like pie in the sky when the only available resource for most schizophrenia patients is a traditional healer, Susser said, “I think [community health and gene-based efforts] will come together over time. Over the long term, one can’t be done without the other. You have to do both.”