The “How Do We Assess Quality in the Age of Precision Medicine?” session at the ASCO Quality Symposium on February 26, 2016, provided a nice overview of the challenges physicians and delivery systems are encountering as precision cancer approaches move from the lab and clinical trials into community use.
I would describe the first challenge as too much data and too little evidence. The session chair, Allison Kurian from Stanford, noted that her genetics clinic has gotten substantially more complicated since the days when tests for germline mutations of BRCA1/2 were the only service offered. A multiplex panel for somatic mutations in tumors may currently test for as many as 70 mutations. Whole genome sequencing identifies innumerable variants, most of them of unknown significance. Decisions must be made to act on some variants based on suggestive preliminary data rather than definitive studies. Our understanding of the implications of genetic variants simply cannot keep up with the pace at which variants are being discovered.
Next come work force issues. Clinicians may find it difficult to keep up with the rapid developments in precision medicine and may at times order a test (or tests) without fully understanding the implications. Even when they do understand, there is an intellectual and time cost involved in integrating complex information of uncertain value with other patient information to arrive at a set of treatment options (or risk management for germline mutations). Clinical geneticists can help with interpreting results but there are too few to meet demand. Limited availability is also a problem with genetic counselors, leaving clinicians to explain the purpose and results of the tests to patients. A great opportunity for team-based care is being lost because of a lack of qualified team members.
Then there are patients. Only about half of whites, and a third to a quarter of non-whites, have been shown to understand germline genetic testing that has been used for decades. Genetic testing raises fear, sometimes warranted, of discrimination. Imagine the reaction of newly diagnosed patients already overwhelmed with information when they are told that their tumor genetic test results are of unknown significance. What will happen when cancer survivors who believe they have completed treatment learn that a variant in their tumor has now been shown to indicate a particularly aggressive cancer, for which there is a new treatment? Decades of declining scientific literacy have left many people ill-prepared to understand care that may determine how long they live.
The last thing I will mention is cost. Lee Newcomer from UnitedHealthcare described a project in which consultants discovered that thousands of different codes being used to justify hundreds of different genetic tests. Yet his company is unable to determine which tests are most informative for patient care and which labs perform those tests most reliably. And the return on investment in terms of patient benefit are often unknown.
To summarize, precision medicine is being practiced in a context of information overload, inadequate staffing, uninformed patients, and growing expenditures. Is this so different from other areas of medical care?