Genes are discrete regions on a DNA molecule that determine specific characteristics of a living cell’s structure or function. Genomics is a branch of molecular biology concerned with studying, defining and cataloging genes, and their association with states of disease, health, and specific physical characteristics. The Human Genome Project, spearheaded by the National Institutes of Health in 1990, undertook the ambitious goal of mapping the entire human genome; it was completed in 2003, producing a whole genetic blueprint for human beings. It’s completion marked an explosion in biotechnology and medicine that continues to this day.
Traditional medical treatments take a ‘one-size-fits-all’ approach that is rapidly being replaced by an individualized or genomic medicine model in which medical care is customized to the patient. Genomic medicine (also called “personalized medicine”) applications utilize knowledge of an individual’s unique genetic makeup, lifestyle, and environment and how these factors interact with each other to produce or protect the person from disease. Thus, the shift from reactive to proactive/predictive medicine marches forward. Personalized medicine promises to transform the practice of healthcare to customized care-from diagnosis to treatment to prevention.
At the present time, cancer treatment is the best example we can look to for how personalized medicine is applied. Genes belonging to a specific individual (identified by testing blood or tissue) are identified to determine what specific chemotherapy drug or dosage should be given to that particular patient. Personalized medicine can also determine who should be monitored more carefully during cancer treatment to protect against complications or safety issues associated with certain treatments. This reduces trial-and-error prescribing and is referred to as “targeted therapy.” The number of targeted therapies for all diseases has increased dramatically over the past ten years and continues to grow at an exponential rate.
Unfortunately, genomic medicine is most utilized once an individual already has cancer, even though we know that some individuals carry a much higher risk of developing cancer due to their genetic heredity. Examples include individuals who have familial adenomatous polyposis (strongly associated with colon cancer) or BR-CA mutations (strongly associated with breast, ovarian, pancreatic and prostate cancer). These are referred to as germ-line mutations because they are inherited from our biologic parents, as opposed to somatic mutations. Somatic mutations occur in cancers that develop due to environmental influences (such as smoking) or in sporadic mutations of DNA and are not inherited. Germ-line mutations that cause cancer are often suspected because of an individual’s family history of cancer.
Thus, individuals who may be predisposed to certain cancers are, more and more, able to be detected by new laboratory tests that detect specific genes or genetic mutations associated with cancer. Recently, the Centers for Medicare and Medicaid Services ruled that Medicare would pay for these tests in patients with advanced (Stage 3 or 4) cancer. Whether they will cover this testing for individuals without cancer who may have a hereditary predisposition, or in those with early-stage cancer, is still not answered. The consequence of this policy is to deny access for early-stage cancer testing and also for individuals who have yet to develop cancer but are predisposed to do so due to their genes.
If screening programs utilizing genetic testing for cancer predisposition drive up healthcare costs, should they be used? Certainly catching cancer before it is advanced, and better yet, before it has even developed, will result in lower healthcare costs in the long run over the course of the individual’s lifetime, and then the question answers itself.
Who should pay for these new tests? Should massive screening programs be implemented? Should health insurance companies be required to cover this testing? Should government programs (i.e., Medicare and Medicaid) cover this testing?
Medical laboratory testing is often considered to be of low value and is not well understood by the general public, yet it is estimated that 70% or more of medical decisions are based upon laboratory results. Personalized medicine testing is an esoteric form of laboratory testing that has many positive clinical uses that benefit patients, and is becoming more widely available and expanding to encompass new applications on practically a daily basis. This presents a conundrum for healthcare providers who order these tests, and for those who pay for medical services since these tests are often expensive to perform, interpret, and use for patient care.