Elliott, M. 2, Hardman, J.1,2, Olaya, L. 1, Malek, J.1,2, Hookins, B.1, Chua, E.3, Gupta, R.4, McLennan, S.1
1 Charles Perkins Centre, University of Sydney, NSW, Australia
2 Department of Otolaryngology, Head and Neck Surgery, Royal Prince Alfred Hospital, NSW, Australia
3 Department of Endocrinology, Royal Prince Alfred Hospital, NSW, Australia
4 Department of Pathology, Royal Prince Alfred Hospital, NSW, Australia
Aims: The American Thyroid Association (ATA) has developed a risk stratification guideline(1) for Papillary Thyroid Cancer (PTC) treatment. However there are few markers to target treatment and monitor recurrence and measurement of miRNA may have some utility in this regard. In this study we aimed to identify miRNAs differentially expressed in association with risk of recurrence in tissue and in the circulation.
Methodology: Formalin fixed, paraffin embedded (FFPE) tissue samples (n=4/ risk group) were obtained from our tumour bank and miRNAs extracted for array analysis. In a second study serial serum samples (n=80) were obtained from patients with different risks of PTC recurrence i.e. low (n=17), intermediate (n=7), high risk (n=3), malignant (n=3). Samples from patients with benign (n=7) and no thyroid disease (n=7) acted as controls. The effect of collection tube type on circulating miRNA levels was also examined.
Results: Analysis of FFPE samples found 25 miRNA differentially expressed between low and high-risk groups. Novel identified miRNAs (miRNAs 10 and 31) and miRNAs known to be altered in PTC (miRNAs 146, 221 and 222) were selected for investigation in the circulation. Circulating miRNA levels were not affected by EDTA or serum collection tube (p=0.34). Ongoing analysis will compare expression levels between risk groups and the affect of thyroidectomy.
Conclusions: Understanding the miRNA profile in PTC in association with risk has potential to assist in early identification of those patients that require more aggressive treatment. Knowing the trend across time will aid in assessing recurrence.
- Haugen BR et al 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid : official journal of the American Thyroid Association 26:1-133.