Author Interviews, Brigham & Women's - Harvard, Cancer Research, Genetic Research, JAMA / 15.12.2017
Most Laboratory Testing For Cancer-Causing Gene Mutations Found Reliable
MedicalResearch.com Interview with:
Annette S. Kim, MD, PhD
Associate Professor, Harvard Medical School
Brigham & Women's Hospital
Boston MA 02115
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The recent debate on laboratory developed tests (LDTs) and FDA-approved companion diagnostics (FDA-CDs) has centered upon both the regulatory and performance aspects of LDTs and we, at the College of American Pathologists (CAP), had the data through our proficiency testing (PT) programs to address the latter point, performance that we wanted to share with the community. We analyzed almost 7000 PT responses on three molecular oncology tests, those for BRAF, EGFR, and KRAS mutations, and found that both LDTs and FDA-CDs demonstrated excellent performance, with both test types exceeding 97% accuracy overall.
The second key finding of the study was that more than 60% of all laboratories in our study that were using an FDA-CD kit report using it with modifications from the FDA-approved protocol. These modifications in fact render these test LDTs. These modifications appear to be driven by the exigencies of real day-to-day clinical practice that requires adapting the assays to meet the needs of a variety of clinical situations that may not be accommodated by the FDA-approved protocol. These modifications include, for example, the testing of other tumor types that may carry targetable variants, different types of input specimen preparations available in pathology such as cytology smears or other fresh specimens rather than paraffin blocks, and availability of different methods of DNA quantification that those mandated by the FDA approval based upon pre-existing technologies in the laboratories. In the clinical laboratory, we are always acutely aware that there is a patient awaiting this result.
Therefore, we validate our assays to ensure that we can provide reliable and accurate results from our laboratory under as many varied clinical situations as possible. These data support that practice.
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