An Exploratory Pilot Study of Peripheral Blood MicroRNA Markers in Patients with Papillary Thyroid Cancer

Dr Petros Perros, Consultant Endocrinologist and Professor Simon Pearce, Consultant Endocrinologist, University of Newcastle

Introduction

About 2,500 people are diagnosed with thyroid cancer in the UK every year. It is one of the fastest rising cancers among women. The majority of people who are diagnosed with thyroid cancer survive for many years, but have to have checks regularly as the cancer can return even 30 years after the original diagnosis. In about one third of people who have been treated for thyroid cancer, the conventional tests to check if the cancer has come back are difficult or impossible to interpret. The burden on the lives of these patients imposed by the uncertainty about their cancer is significant. New technologies and tests have been emerging for the diagnosis of cancers. One of these is detecting “microRNAs”. These small chemicals are thought to be released by cancer cells and may be used as markers of cancer.

Final report

A number of studies have already shown promising results in thyroid cancer, but have concentrated on detecting microRNAs in tissue samples. We wanted to explore whether such markers could be found in blood samples of patients with thyroid cancer, as blood is much more accessible and convenient that biopsies or other complicated investigations. With generous support from the British Thyroid Foundation we were able to undertake this project. Blood samples from ninety patients with a history of papillary thyroid cancer were studied. We used state of the art technology and probed for all microRNAs that could be identified in the blood samples. We were able to identify up to 178 microRNAs in blood samples. Of these, 18 microRNAs showed an association with metastatic thyroid cancer. One microRNA was particularly promising, which has not been reported to be associated with thyroid cancer, though it has been implicated in breast, ovarian, pancreatic cancer and malignant melanoma. Three other miRNAs previously reported to be differentially expressed in thyroid cancer tissue, were also found to be associated with metastatic thyroid cancer in our study.

Our findings suggest that it may be possible to use microRNAs as markers of thyroid cancer in a blood sample. Our study has also identified a potential new microRNA marker of thyroid cancer, not previously described. These data are promising but must still be interpreted with care and must be regarded as preliminary. Additional work is required to confirm and explore the potential role of such tests in clinical practice.

Our team wish to thank the BTF for financial support and our patients from the Thyroid Cancer Clinic at the Northern Centre for Cancer Care, Newcastle upon Tyne for donating blood samples.

Please see the final report