In a new era of precision medicine, the role of genetics is becoming increasingly critical to determine who might benefit from such therapies that go after specific cancer-causing genetic mutations. A growing number of oncologists now order a DNA analysis of patients’ cancerous tumor tissue obtained through a biopsy to better understand how patients’ unique biology might drive their treatment.
Yet identifying more mutations might not be helpful to doctors or patients. In what has become a common theme in genetics research, scientists are discovering genes faster than they can interpret them.
For example, one recent Johns Hopkins University School of Medicine and Vanderbilt University Medical Center study of genetic testing results of 100 metastatic breast cancer patients that was published last year in JAMA Oncology found that 14 patients had variants believed to cause cancer, yet in half those cases it was unclear how strong the link was. Even more confusing: 21 of the patients had what are known in genetics lingo as “variants of unknown significance” — meaning having no known impact on one’s health.
In other words, patients might receive reports with a lot of potentially worrisome information that doctors don’t know how to use — much less turn into meaningful treatment recommendations.