Evidence Matters in Genomic Medicine

A new IOM report makes recommendations that aim to ensure that progress in omics-based test development is grounded in sound scientific evidence and is reproducible, resulting in improved health care and continued public trust in research.  Another new IOM roundtable workshop report discussed the differences in evidence required for clinical use, regulatory oversight, guideline inclusion, coverage, and reimbursement of genomic diagnostic tests and focused on ways to clarify pathways for using such tests in clinical settings. Recently, the NIH made a beta version of Genetic Test Registry (GTR) available online.  The GTR provides a central location for voluntary submission of genetic test information by developers. The GTR includes information on the test’s purpose, methodology, validity, evidence of the test’s usefulness, and laboratory contacts and credentials. The information provided is not verified by NIH, but assumed to be accurate by the submitting party. The GTR will not obviate the need for evidence-based evaluation of genetic tests and development of recommendations. However it is on track towards becoming useful to advance research and clinical practice. 

So what are health care providers to do today when considering ordering a genomic test to diagnose, prevent or ameliorate a medical condition? Ultimately, providers and patients have to ask whether or not such a test can help in management of a health condition, and what is the balance of benefits and harms of such testing to the patient, the family, the community and the healthcare system.  Genomics and related fields (“Omics”) are rapidly emerging, resulting in many tests proposed to improve health. Since 2009, the CDC’s online GAPP Finder has catalogued more than 400 emerging tests, most of which are related to cancer. Unfortunately, beyond management of rare, single gene disorders, most new tests are not ready for use in clinical practice. The question is how do we know what is ready and what is not. After all, many people would like to have access to their personal genome information regardless of health related utility. This was reflected in the recent readers’ response to our blog on the topic of personal genomics.

In response to the need for evidence in genomic medicine, starting in 2005 the CDC Office of Public Health Genomics convened the Evaluation of Genomic Applications in Practice and Prevention (EGAPP) working group, an independent, multidisciplinary and non-regulatory panel. The EGAPP working group develops and applies systematic methods to evaluate evidence for validity and utility of genomic applications used in specific clinical scenarios. To date, formal evaluation of 8 genomic test(s) have been conducted. One “positive” recommendation from the EGAPP working group is to offer genetic testing for Lynch syndrome to all individuals with newly diagnosed colorectal cancer (CRC) to reduce morbidity and mortality in relatives. Implementation of this recommendation today can save many lives.

More often, however, the EGAPP working group has found that there simply are not enough relevant, high quality studies available to support an evidence-based recommendation either for or against use of specific tests.  EGAPP recommendation statements identify specific gaps in knowledge to inform additional research. The EGAPP working group has been a pioneer in establishing evidentiary principles and published methods tailored to emerging genomic applications in medicine and public health. With so many new genomic tests becoming available and the need to develop novel evidence review processes, It is not surprising that only a few tests have been assessed and that the evidence-bar may seem too high.

As the number of genomic tests increases over the next few years, we need processes such as EGAPP, that provide an “honest broker” function in the evaluation of these technologies to inform providers, policy makers, patients and other stakeholders.  These processes involving professional organizations, researchers and consumers are crucial to balance the need for technological innovation with the need to show improved health outcomes, in order to realize the potential of genomic medicine in the 21^st century.

We welcome readers’ suggestions and feedback on evidence matters in genomic medicine.