Genomic test limits surgeries among patients with indeterminate thyroid nodules

BOSTON — Thyroid gene expression classifier testing used to identify suspicious thyroid nodules in patients reduced the overall surgical rate when compared with a historical control group that did not undergo the testing, according to study findings presented here.

“Our findings demonstrate the significant positive, real-world impact that the Afirma [gene expression classifier] is having on patient care,” Richard T. Kloos, MD, senior director of endocrinology at Veracyte, said in a press release. “Specifically, these data show that, across a range of clinical settings, the test is helping physicians improve care by avoiding unnecessary diagnostic surgery for their patients. This is important because these surgeries are invasive [and] costly and often subject patients to lifelong daily thyroid hormone medication.”

Richard T. Kloos

In a systematic review, Kloos and colleagues analyzed data from 13 studies including 1,842 patients who underwent gene expression classifier (GEC) testing that yielded a diagnostic result (patient range, 13-497). Researchers abstracted the rates of benign and suspicious GEC results, operative rates in each group, malignancies found at surgery and median follow-up, and analyzed the impact of GEC testing on patient management vs. historical control groups.

Within the cohort, 833 patients (45.2%) had benign GEC results, of which 87 (10%) went on to surgery and seven (1%) were malignant. GEC results were suspicious for 1,009 patients (54.7%), of which 756 (74.9%) underwent surgery and 243 (33%) were malignant.

Three studies compared management with GEC testing with historical control groups from their institutions and found that 900 of 1,569 patients (61.3%) with indeterminate thyroid nodules proceeded to thyroid surgery. In comparison, 843 of 1,842 patients (45.8%) managed with GEC testing proceeded to surgery, a 25% lower overall surgery rate.

In the six studies that included follow-up of benign nodules (n = 457; mean follow-up range, 7-26 months), 393 patients (86%) had avoided surgery.

In a second study, Michael Donovan Traynor Jr., of the University of North Dakota School of Medicine and Health Sciences in Fargo, North Dakota, and colleagues conducted a retrospective review of medical records from 66 patients who underwent fine-needle aspiration of thyroid nodules with indeterminate results, as well as GEC testing, between April 2012 and October 2014 at Sanford Health in Fargo, North Dakota. Within the cohort, 37 patients had benign GEC results (56.1%); 29 patients (43.9%) had suspicious results. Researchers found that 35 of 37 patients with benign GEC results elected conservative follow-up; 26 of 29 patients with suspicious results underwent surgery; rate of malignancy in suspicious nodules was 42.3%.

“Since the [Afirma GEC] test’s launch in 2011, we estimate that it has helped more than 20,000 patients avoid an unnecessary thyroid surgery and has provided hundreds of millions of dollars in savings to the health care system,” Bonnie H. Anderson, president and CEO for Veracyte, said in a press release. – by Regina Schaffer

Reference s :

Kloos RT, et al. Poster board SAT 284.

Traynor MD Jr., et al. Poster board SAT 282. Both presented at: The Endocrine Society Annual Meeting; April 1-4, 2016; Boston.

Disclosure: Kloos and colleagues are employees of Veracyte Inc. Traynor and colleagues report no relevant financial disclosures.