Thyroid nodules are thought to be present in about half of all people, but very few of these are cancerous. Thyroid nodules are first assessed using fine needle aspiration cytology, a procedure to remove thyroid cells for examination. But about a third of results come back as indeterminate and requires a diagnostic thyroidectomy. Of these, only about 20% turn out to be malignant. Obviously that 20% require further treatment, usually a full thyroidectomy. But the other 80% have had unnecessary, but currently unavoidable, surgery.
New research has pointed to a set of diagnostic biomarkers which are able to distinguish between malignant and benign thyroid nodules which appear to be intermediate from fine needle aspiration. This includes analyzing eight biomarkers each capable alone, or in combination, to distinguish between malignant and benign samples. This gene activity set was able to correctly identify malignant and benign tumors 89% of the time.
This has made it possible to create a new algorithm for evaluating thyroid nodule:
1) Check for mutations in BRAF: Almost half of all the malignant samples (but none of the benign samples) carried the V600E mutation in the gene BRAF. This should be treated as suspected cancer.
2) Check KIT level: The gene with the highest predictive power was KIT. KIT activity is turned down in thyroid cancer, so BRAF-normal samples, with low levels of KIT, should also be treated as suspected cancer.
3) Samples with normal BRAF and indeterminate KIT activity should be examined with the whole panel.
4) Any remaining ambiguous results can then be tested with the current diagnostic thyroidectomy.
Following this stepwise approach, researchers say they could potentially reduce the numbers of people with benign nodules being treated with radical surgery by almost 50%, yet still identify the people who require thyroidectomies to treat their cancer.
Thyroid nodule is a growth (lump) in the thyroid gland. The thyroid gland is located at the base of the neck. Thyroid nodules are more common in women than in men and the chance of getting a thyroid nodule increases with age. Thyroid nodules are mostly asymptomatic, but may cause goiter or an enlarged thyroid gland or lump(s) in the neck, hoarseness or changing voice, pain in the neck, and problems breathing or swallowing.
A new set of diagnostic biomarkers can prevent unnecessary surgeries in patients with indeterminate thyroid nodules that are not clearly benign or malignant. Consult your physician immediately if you notice lump in the neck, hoarseness, and problems breathing or swallowing. In cases when your physician suggests thyroidectomy (a procedure that removes the thyroid gland), ask him if you benefit from new biomarkers studies.