Ultimately, the success of personalized medicine will rise or fall on its ability to demonstrate its value to the healthcare system, to the industries that develop its products, and to patients. The promise of personalized medicine, for which tangible evidence already exists, includes the ability to:
- Shift emphasis in medicine from reaction to prevention,
- Enable the selection of optimal therapy and reduce trial-and-error prescribing,
- Make the use of drugs safer by avoiding adverse drug reactions,
- Increase patient compliance with treatment,
- Reduce the time and cost of clinical trials,
- Revive drugs that are failing in clinical trials or were withdrawn from the market,
- Reduce the overall cost of healthcare.
Personalized medicine introduces the ability to use molecular markers that signal the risk of disease or its presence before clinical signs and symptoms appear. This information underlies a healthcare strategy focused on prevention and early intervention, rather than a reaction to advanced stages of disease. Such a strategy can delay disease onset or minimize symptom severity.
One example is a test used to look for BRCA1 and BRCA2 genetic mutations indicating a hereditary propensity for breast and ovarian cancer.
Women with BRCA1 or BRCA2 genetic risk factors have a 36% to 85% lifetime chance of developing breast cancer, compared with a 13% chance among the general female population.
For ovarian cancer, women with certain BRCA1 or BRCA2 gene mutations have a 16% to 60% chance of disease, compared with a 1.7% chance among the general population. The BRCA1 and BRCA2 genetic test can guide preventive measures such as increased frequency of mammography, prophylactic surgery, and chemoprevention.
Over 1,300 genetic tests exist that signal inherited susceptibility to conditions as wide-ranging as hearing loss and sudden cardiac arrest. While not every test has a therapeutic option, a genetic diagnosis often permits targeted prevention or mitigation strategies.
On average, a drug on the market works for only 50% of the people who take it. The consequences in terms of quality and cost of care are significant, leaving patients to contend with their disease and their medical bills as they switch from one drug to another until they find an effective therapy. Studies have linked differences in response to the differences in genes that code for the drug-metabolizing enzymes, drug transporters, or drug targets. The use of genetic and other forms of molecular screening allows the physician to select an optimal therapy the first time and avoid the frustrating and costly practice of trial-and-error prescriptions.