Genomic testing—identifying variants, like mutations, in tumor cells to inform patient treatment options—occasionally comes with unanticipated results that clinicians have to address with their patients. Clinicians and patients alike are often hopeful that tumor genomic testing will identify a personalized cancer treatment. Indeed, many patients have benefited from being candidates for new targeted therapies identified through genomic testing.
However, the reality is that genomic test results may not always provide patients and providers with clear answers about their treatment options. Test results can come back with multiple variants that require a trained medical professional to sift through. And in some instances, a genomic test may provide no clinically useful information, perhaps showing nothing actionable in the data or only providing options for a clinical trial a patient can’t access.
Tumor genomic testing can also return results of variants that have unknown significance to the cancer diagnosis or have no known targeted therapies associated with it. Despite vast advancements in genomic testing and targeted therapeutics through the past five years, the extent of available precision oncology treatments approved through the U.S. Food and Drug Administration (FDA) is still limited. Without FDA-approved agents or an ongoing clinical trial to target a specific mutation, an identified variant with an unknown significance has few treatment options.
Genomic tumor testing can also produce other unanticipated results related to germline, or hereditary, cancer risks. In some instances, genomic tumor tests may identify variants that are associated with inherited risks. Despite having separate functions, germline genetic and somatic genomic testing results have been known to overlap at times, which leads to widespread impact for patients and their family members. If tumor testing reveals an inherited variant, healthcare professionals will need to order specific testing to confirm the germline change. Such patients should also be referred to a hereditary cancer expert for further consultation. But when this occurs in practice, patients often haven’t been fully informed of the possibility ahead of time.
When looking to understand genomics, remember that it’s a rapidly evolving field. Oncology professionals, especially nurses, must recognize that the knowledge base of tumor variants is still imperfect and growing all the time. What’s considered an uncertain mutation with no actionable data today could be reclassified as pathogenic or disease causing next week. At times, retesting a patient could be warranted if treatments and tumor testing technology have advanced. Retesting may also be important for individuals who experience recurrence. Because the tumor genome changes, variants found in a patient at initial diagnosis and treatment could be different from the profile found with recurrence. Clinicians need to recognize the fluid nature of genomic testing and understand that guidelines about when retesting should occur are evolving.
Despite the challenges that clinicians face in genomic testing, solutions come down to improved communication and setting appropriate patient expectations. Nurses are keenly equipped to build relationships with their patients and address these issues. Ensuring that patients recognize the purpose of testing and how to interpret their results, treatment options, and follow-up steps can eliminate miscommunication. Many nurses are already advocating for their patients, and this is just another great opportunity to increase their knowledge in precision oncology and continue to fill an important role for their patients.