6 September 2019 - - Newly published new data that further define the genomic landscape around thyroid cancer, US-based genomic diagnostics company Veracyte, Inc. (NASDAQ: VCYT) said.
The study findings help characterise the role of specific gene alterations known as variants and fusions in predicting thyroid cancer and also reinforce the potential for Veracyte's AfirmaXpression Atlas genomic test to help guide personalised surgery and treatment decisions for patients with suspected or confirmed thyroid cancer.
The new study appears online in the journal Thyroid.
For the new analysis, researchers evaluated data from 61 published studies involving 4,648 thyroid nodule samples to determine the frequency of specific variants and fusions and the likelihood of cancer when they are detected in preoperative patient samples.
The study focused on thyroid nodule samples that were indeterminate not clearly benign or malignant following traditional diagnostic testing.
More than one quarter of the total thyroid nodules were positive for at least one gene alteration, and of those, 94% were DNA sequence variants and 6% were RNA fusions;
Only five specifically reported gene alterations appeared in 10 or more nodules in the collective cohort and less than one % of the total thyroid nodules had more than one variant or fusion;
The positive predictive value or likelihood that a variant or fusion was found in thyroid nodules that ultimately proved cancerous varied significantly among the five most prevalent gene alterations [BRAFV600E (98%), PAX8/PPARG (55%), HRASQ61R (45%), BRAFK601E (42%) and NRASQ61R (38%)]; and
The cumulative PPV for these five gene alterations was 77%; the PPV decreased to 47% when BRAFV600E was excluded.
The study findings support the use of the Afirma XA, an RNA whole-transcriptome sequencing-based test that detects expressed DNA variants and RNA fusion partners in over 500 genes that are associated with thyroid cancer.
DNA variants are alterations in the most common DNA nucleotide sequences and RNA fusions are chromosomal rearrangements that juxtapose two different genes together to form a fusion gene.
The Afirma XA is performed on fine needle aspiration samples of thyroid nodules deemed suspicious for cancer by Veracyte's Afirma Genomic Sequencing Classifier, as well as those that are suspicious for or have been diagnosed as cancer based on cytopathology.
The Afirma GSC and Xpression Atlas provide physicians with a comprehensive solution for a complex landscape in thyroid nodule diagnosis and individualization of care.
Veracyte developed the Afirma GSC with RNA whole-transcriptome sequencing and machine learning.
The test helps identify patients with benign thyroid nodules among those with indeterminate cytopathology results in order to help patients avoid unnecessary diagnostic thyroid surgery.
The Afirma XA provides physicians with genomic alteration content from the same fine needle aspiration samples that are used in Afirma GSC testing and may help physicians make decisions about the surgical or therapeutic pathway for their patients with greater confidence. The Afirma XA includes 761 variants and 130 fusion partners in over 500 genes that are associated with thyroid cancer.
Veracyte (NASDAQ: VCYT) is a leading genomic diagnostics company that improves patient care by providing trustworthy and actionable answers to challenging clinical questions.
The company's products uniquely combine advanced genomic technology, clinical science and machine learning to provide answers that give patients and physicians a clear path forward, informing both diagnosis and treatment decisions without the need for costly, risky surgeries that are often unnecessary.
Since its founding in 2008, Veracyte has commercialised seven genomic tests and is transforming the diagnosis of thyroid cancer, lung cancer and idiopathic pulmonary fibrosis. Veracyte is based in South San Francisco, California.