Preventive medicine can be more precise and precision medicine can be more preventive!Posted on by
In a recent JAMA viewpoint, Psaty and coauthors compare precision medicine and preventive medicine as two distinct models in medicine and public health. They use the example of hemophilia B to illustrate how new gene therapy can successfully target treatment with high specific-activity factor IX variant. They contrast this model of precision medicine with the practice of preventive medicine where interventions target disease risk factors to reduce disease risk (e.g. high blood pressure treatment to prevent heart attacks and stroke). They posit that hemophilia and hypertension represent two different approaches. The first is deterministic, where targeting the precise biological deficit or derangement can be effective. The second is probabilistic and applies to common conditions, such as hypertension and hyperlipidemia, where high levels of the risk factor increase the probability of a heart attack or stroke. They further state that precision medicine often has a gene-centric approach, and they discuss the importance of public health efforts to increase prevention of cancer and cardiovascular disease and to reduce social and racial health disparities.
The dichotomy between precision medicine and preventive medicine may be unwarranted
While public health efforts need focus on disease prevention and address health disparities, there is really no dichotomy between precision medicine and preventive medicine. As envisioned by the US Precision Medicine initiative (All of US Research Program), the term precision medicine encompasses both treatment and prevention: “Precision medicine is a revolutionary approach for disease prevention and treatment that takes into account individual differences in lifestyle, environment, and biology.” There is a common notion that precision necessarily implies biologic determinism. While this may be true for certain conditions, most human diseases are due to complex gene-environment interactions which can only lead to a probabilistic (albeit more precise) approach to treatment and prevention.
Cardiovascular disease and cancer both illustrate the spectrum of “precision” that we can apply to disease prevention. Familial hypercholesterolemia (FH), a common autosomal dominant genetic disorder affecting more than one million people in the United States, significantly increases the risk of premature deaths from heart disease. FH is currently underdiagnosed and undertreated. We will need more precision in finding people with FH, in addition to general cholesterol education campaigns. Perhaps more importantly, screening of first degree relatives of FH patients is essential to diagnose and treat FH in relatives. We are missing out on a subpopulation that deserves more targeted efforts in disease prevention by not adequately targeting FH patients and their families with the population approach to cholesterol education and reduction. Furthermore, precision prevention is not just about genes but also can be driven by the use of population level data to target interventions. For example, blood pressure reduction to prevent cardiovascular events can be targeted at hard to reach subpopulations at high-risk based on geographic, sociodemographic, health systems, or other factors.
Precision strategies can go beyond genomic-based screening, to integrate environmental and social determinants of health
In a recent article on precision cancer prevention, Rebbeck and colleagues discussed two approaches to cancer prevention: population approaches (e.g., policies to reduce tobacco use) and high-risk strategies interventions (e.g., smoking cessation). Knowledge about cancer biological mechanisms, exposures, and genetic susceptibility may well provide opportunities to develop precision prevention and early-detection strategies. Precision strategies aim “to understand the basis of risk, identify groups that optimally benefit from interventions, characterize heterogeneity in intervention responses, optimize intervention timing, and minimize toxicities.” While currently available cancer prevention and early-detection approaches can reduce a large proportion of the population cancer burden, even if fully implemented, they cannot eliminate cancer. New approaches that use emerging knowledge of molecular and biological cancer mechanisms can be developed, evaluated, and implemented.
In their recent review article, Biro and coauthors discuss how the term ‘precision prevention’ is fairly new and first appeared in a 2014 editorial, ‘Precision prevention involves use of biologic, behavioral, socioeconomic and epidemiologic data to devise and implement strategies tailored to reducing cancer incidence and mortality in a specific individual or group of individuals.’ Since then, other definitions have emphasized that precision can go beyond genomic-based screening, to integrate environmental and social determinants of health.
The evolution of medicine and public health will usher in a new era of precision medicine and precision public health
Lyles and coauthors recently explored how advances in precision medicine and individualized patient treatments need to be accompanied by continued attention to tailored population health and prevention strategies. They reviewed a series of specific recommendations that have resulted from the All of Us Research Program and the 2016 Gates Foundation Precision Public Health Summit.
Both medicine and public health will evolve over time as a result of the use of better data, information, and technologies both at the micro level (e.g. genomics) and the macro level (e.g. health information systems). This evolution will usher in a new era of precision medicine and precision public health whose collaborations will be needed to enhance both treatment and prevention, and to improve the overall health of the population.