Noninvasive Test to Evaluate Aspirated Thyroid Nodules With Indeterminate Cytology
Posted: Monday, December 17, 2018
Patients whose aspirated thyroid nodules have indeterminate cytology may potentially avoid diagnostic surgery to determine the presence of cancer with the use, instead, of multigene genomic classifier testing. In fact, in a prospective blinded multicenter study, David L. Steward, MD, of the University of Cincinnati Medical Center in Ohio, and colleagues documented a high sensitivity and correspondingly high negative predictive value with the genomic test in this patient population. Their findings were published in JAMA Oncology.
The team evaluated the diagnostic accuracy of ThyroSeq v3, a multigene classifier test. Ultimately, 286 aspirated samples that met eligibility criteria underwent molecular analysis; the original population included 782 patients, with 1,013 nodules, from 10 medical centers.
The primary outcome was the test’s diagnostic accuracy for thyroid nodules with Bethesda III and IV indeterminate cytology. (About 20% of fine-needle aspirations of thyroid nodules have indeterminate cytology, and most are classified as Bethesda III or IV.) “The multigene [classifier] test was highly sensitive (94%) and reasonably specific (82%) for discriminating benign from [both] malignant nodules [and] noninvasive follicular thyroid neoplasms with papillary-like nuclei,” reported Dr. Steward and colleagues. A total of 61% of nodules yielded negative results; of them, 3% were shown by histopathology to have residual cancer risk.
“The observed 3% false-negative rate was similar to that of benign cytology,” the team wrote. “It is reassuring that all false-negative cases…were low-stage and low-risk cancers by the American Thyroid Association criteria.” And for patients whose nodules are positive for cancer, the genetic information gleaned from the test, along with imaging results and other data, could further support individualization of their treatment plans.