The Coming Revolution in Medicine

Published April 1, 2002

In a 1901 article summarizing medical progress in the nineteenth century, Sir William Osler wrote, “… bacteriology opened unheard of possibilities for the prevention of disease.” Now, as we enter the twenty-first century, the same can be said of the potential for genetics and biotechnology.

The first project to map the human genome began in 1989. In September 2000, two competing efforts published “rough drafts” of the genome. In 2001, many billions of dollars were invested in basic science, research and development, and clinical studies to exploit the exploding universe of genome and genome-related information becoming available. These investments range from development of special-purpose supercomputers to process the huge volumes of data to clinical trials of DNA-replacement techniques.

Many forecasts have been made for the potential of genetic-based biotechnology. These forecasts suggest at least some of the potential developments may have profound impacts on the supply and demand for medical care and the medical service industry in the next 25 years.

Anticipated Pace of Medical Progress

Many researchers and industry analysts have speculated about the pace at which genetic biotechnology discovery and development will bring forth useful diagnostic and therapeutic applications. An amalgam of several forecasts is outlined below:

Through 2010:

  • Identification of genes responsible for many common diseases.
  • Understanding of the proteomics of many single-gene related diseases, leading to rationally designed drugs to treat them.
  • Sequencing the genomes of many disease-causing bacteria and parasites to identify their disease-causing mechanisms.

Through 2020:

  • Understanding of the mechanisms of diseases caused by polygenic interactions with environmental factors.
  • Routine use of DNA-based diagnostic tools.
  • Development of many rationally designed drugs and therapies based on knowledge of gene expression of proteins.
  • Therapies based on tissue engineering (e.g., repair of incompetent esophageal and urethral sphincter; regeneration of cartilage in arthritic joints).
  • Xenotransplantation of organs from genetically modified cloned animals.
  • Gene therapy for single-gene diseases; several hundred diseases may be curable.

Beyond 2020:

  • Early detection and prevention will eliminate genetic disorders before symptoms arise.
  • Many of the diseases caused by known viruses and bacteria will be prevented or quickly treated.

Some observers anticipate even more rapid progress than that outlined above. One event in our recent history gives a hint of what to anticipate from the biotechnology boom.

After President John F. Kennedy announced the goal of landing men on the moon within 10 years of May 25, 1961, reporters related that NASA officials they interviewed “didn’t have a clue” about how to go to the moon. The United States had only primitive computers and rockets, and many thought every scientist and engineer in the nation would have to be drafted into the effort. Based on their current state of technical knowledge, many scientists and engineers were highly skeptical about reaching the goal in twice the time.

Today, many of those in the scientific and medical communities seem to have equal difficulty imagining that technology we don’t yet know about, rather than developments based on our current knowledge, will produce the breakthroughs and products we all hope biotechnology will yield.

Presidents Kennedy and Lyndon B. Johnson achieved their goal by managing the budget appropriations process to secure all the funding NASA requested. Similarly, the key to realizing quick results from the biotechnology industry lies in the capital market; adequate supplies of capital to fund private genetic research and development will assure the fastest results possible. Moreover, the private-sector environment presents stronger incentives and fewer constraints than those faced by public-sector enterprise.

Unlike the government’s program to send men to the moon, private-sector genetic research and development efforts are aiming at tangible payoffs, can take significantly greater risks, and can field multiple approaches to discovery and product development.

For example, while both projects to map the human genome published results in the year 2000, the public-sector effort took 11 years; the private effort, utilizing more modern technology and ample funding, took two years.

Transformation to Genetic Medicine

It is widely believed that, as more tests for genetic susceptibility to diseases become available, the practice of medicine will evolve from a therapeutic model to a preventive one based on genetics. The new tests will enable detection of common diseases long before patients develop symptoms.

It is estimated there are approximately 4,000 gene disorders. Thousands of tests will likely become available for specific gene disorders and for polygenic predisposition to developing diseases through environmental and behavioral interactions. The availability of tests and possibilities for prevention will stimulate a great patient demand for genetic screening and treatment.

Related developments (e.g., “pharmacogenomics”) in genetic medicine will some day enable physicians to tailor drug treatment to each patient’s specific genetic makeup to maximize the effectiveness of drug therapy for each patient, as well as avoid adverse reactions. Many biopharmaceutical firms are concentrating on finding the small differences in gene sequences (single nucleotide polymorphisms, or SNPs) between individuals that potentially affect disease progression and an individual’s response to therapy. A recent study by Genaissance Pharmaceuticals of 82 individuals found an average of 14 sequence versions for each gene in the human genome.

A pharmacogenomic product exemplifying SNPs is Genentech’s Herceptin monoclonal antibody against the Her2 protein. In clinical trials against breast cancer, Herceptin only performed well in a subgroup of patients (about 30 percent) whose cancer cells were found to over-express Her2. As a result, breast cancer patients are now screened to determine whether their tumor cells over-express Her2, because Herceptin is not effective otherwise. Thus, some patients can be given a drug targeted at their particular variant of breast cancer, while the others will not waste time receiving an ineffective drug.

As more “personalized” drugs become available, genetic testing of patients for their responses to the drugs will become a routine part of prescribing pharmaceuticals in medical practice.

Decline of Hospitalizations and Procedures?

Throughout the twentieth century, the distribution of health care expenditures has been remarkably stable. It has been characterized by an extreme concentration of annual expenditures within a small fraction of the population. Throughout the century, only 30 percent of the population has accounted for 90 percent of annual expenditures on health care. About 12 percent of Americans are hospitalized each year, but they spend 40 percent of health care dollars.

Further, less than one-half of the noninstutionalized population have one or more chronic conditions, but they account for 76 percent of medical care spending. Persons with chronic conditions account for 69 percent of hospital admissions and 80 percent of hospital days.

This historically stable distribution of health expenditures could change significantly early in the twenty-first century if, through advances in biotechnology, we are able to prevent or reduce the incidence of some chronic diseases. For example, some researchers and industry analysts suggest the following scenarios are possible:

  • Annual expenditures on diseases of the circulatory system comprise about 17 percent of total national health care expenditures. In 1996, 20.7 million Americans had a heart condition (excluding hypertension), and 6.34 million heart-related procedures were performed. Discovery of the genetic origins of susceptibility to heart disease and development of preventive measures for hypertension, atherosclerosis, and congestive heart failure could significantly reduce related hospitalizations and procedures such as revascularization.
  • Annual expenditures on diseases of the musculoskeletal system comprise about 6 percent of total national health care expenditures. In 1996, 33.6 million Americans had arthritis and almost 400,000 total knee and hip replacements were performed. Advances in genetic medicine could virtually eliminate the need for surgery in these patients after 2025.
  • Lung disease accounts for approximately 7.3 percent of health expenditures in the United States. About 15 million Americans are affected by asthma; they generate more than 1.5 million emergency room episodes and 500,000 hospitalizations each year. Because asthma is related to known gene mutations, it is possible that further developments could lead to targeted treatment and prevention by 2025.
  • The expanding prevalence of diabetes in the United States has been described as epidemic, expected to reach 23 million in 10 years from about 16 million in 2001. Complications of diabetes, including cardiovascular disease and stroke, diabetic retinopathy and kidney disease, and amputation of limbs account for 10 percent of annual health expenditures, including 25 percent of Medicare expenditures. Type 2 diabetes is a polygenic disorder and accounts for 90 to 95 percent of all diabetes cases. Type 2 diabetes could be preventable within the next 25 years as the disease-causing interactions between genetic predispositions and environmental factors such as obesity and lifestyle are elucidated.

As the predicted advances in DNA-based disease prevention and genetic medical therapies become available over the next quarter-century, a number of procedures in common use today will likely be phased out, as well as the hospitalizations associated with them.

Our experience with public water supply fluoridation may give insight into the potential impacts of advances in genetic biotechnology.

Public water supply fluoridation was initiated in the 1950s to prevent tooth decay in cohorts exposed to it during tooth development. Today, almost two-thirds of the American population drinks from fluoridated public water supplies.

The nationwide prevalence of dental caries—the dental disease that historically consumed the most resources to treat—declined 65 percent in children between 1971 and 1994. The nationwide prevalence of dental caries also has begun to decline in American adults.

The mix of services provided by dentists has changed in response to the changing disease pattern. Between 1959 and 1990:

  • The percentage of patients receiving a one-surface amalgam or an extraction fell from 20.1 percent to 5.3 percent, and from 13 percent to 4.9 percent, respectively;
  • The percentage of U.S. dental patients receiving an oral examination increased from 20.1 percent to 42.8 percent; and,
  • The percentage of patients receiving a prophylaxis increased from 19.9 percent to 38.6 percent.

The decline in the incidence of dental caries resulted in a significant reduction in operative procedures, but preventive services increased to take their place. The same pattern could unfold in medical practice as genetic biotechnology provides the means to reduce the incidence and prevalence of genetic-based chronic disease.

Conclusion

The American public will quickly learn of advances in preventive and therapeutic capability, and will likely demand genetic medical services such as screening for disease predisposition and preventive measures.

The measured prevalence of many diseases will rise above current levels because of early detection. The historically concentrated expenditure at the high-cost tail of the distribution of health care spending may dissipate as high-cost episodes of hospitalization and consumption of high cost procedures are displaced by broad-based screening, early detection, and prevention.

Health expenditures will likely be distributed over a larger proportion of the population as the ability to detect predisposition to chronic disease advances and more disease is prevented or is attenuated in severity.

In fact, the number of elderly (age 65 or greater) becoming chronically disabled has already been declining since the late 1980s. This was manifested, for example, in the number of nursing home residents declining by 200,000 during the 1990s. A number of factors are thought to underlie this trend, including fewer people smoking, new drugs for heart conditions and other illnesses, healthier lifestyles, and advances in medical technology. Advances in genetic biotechnology predicted to occur over the next 25 years could accelerate this trend.

Generally, a shift in the paradigm of medical practice from treatment to prevention will occur based on rapidly increasing capabilities of genetic medicine that will significantly change demands on physicians over the next 25 years. However, the exact pace of change is uncertain at this time. It could proceed much faster than some currently predict.


Jesse Hixson is principal economist for the American Medical Association. An earlier version of this paper was prepared for the American Medical Association’s Council on Medical Service.


For more information …

See Mathew J. Elrod-Erickson and William F. Ford, “Economic Implications of the Human Genome Project,” Business Economics, October 2000, pp. 57-60; and the Journal of the American Medical Association, February 7, 2001, Vol. 285, No. 5.

The Internet offers a wealth of resources on genetics. Among them are Geneletter, http://www.geneletter.com/index.epl; Biospace, http://www.bull-market.com/1biotech.html; and Bio Online Biotechnology, http://www.bio.com.