Thyroid nodules are lumps in the thyroid gland that move up and down with the thyroid gland with swallowing movements and are a very common clinical condition. The incidence of nodules increases with age, and the ratio of women to men is 4:1.
Let’s look at a set of statistics.
As you can see from the graph above, the prevalence of thyroid nodules is high, but the percentage of malignancy is relatively low. Papillary thyroid cancer accounts for a very high percentage of thyroid cancers, reaching 80-90%.
Traditional examination methods for determining benign and malignant thyroid nodules
1.Ultrasound diagnosis
Ultrasound is very reliable for the diagnosis of cystic lesions. It is of little value in distinguishing benign from malignant. However, it is meaningful in identifying the size of nodules, identifying the location of nodules, and guiding the localization of puncture.
2.Fine needle aspiration cytology examination
The widespread use of this method has greatly reduced the number of unnecessary thyroid surgeries, improved the detection rate of intraoperative malignancy, and reduced the cost of thyroid nodule management. The accuracy rate of fine needle aspiration cytology is 70% to 90%, which is related to the experience of aspiration and cytology diagnosis.
3.Nuclear scan
Scans are less significant in distinguishing benign from malignant lesions. Most benign and malignant substantial nodules are low-functioning relative to the surrounding normal glandular tissue; therefore, the finding of cold nodules is rarely specific, and the overlapping uptake of nuclide from surrounding normal glandular tissue can miss the diagnosis of small nodules.
4.X-ray of the neck
Small or sand-like calcifications on nodules may be sand bodies of papillary carcinoma. Large and irregular calcifications can be seen in degenerative nodular thyroid tumors or thyroid cancer. If infiltration or deformation is seen in the tracheal image, it suggests a malignant lesion.
5.Thyroid function measurement
Functionally autonomous toxic nodules are mostly hyperthyroid, early stages of subacute thyroiditis can also be hyperfunctional, and thyroid function in chronic lymphocytic thyroiditis can be normal, hyperactive or hypothyroid.
Each of these tests has its own drawbacks. Ultrasound and nuclear scan have little value in differentiating benign and malignant tumors; X-ray is a radioactive test, which may have some effects on the body; blood measurement of thyroid function cannot be used to determine benign and malignant; although the accuracy of puncture test is relatively high, it is invasive after all, and the cancer rate of thyroid nodules is relatively low. Therefore, many people are not willing to undergo invasive puncture tests.
For those who are unwilling or unsuitable for traditional thyroid tests, are there other accurate and non-invasive tests available?
The good news is that a large study conducted by Mingzhao Xing, M.D., team at Johns Hopkins University School of Medicine showed that 80.4% of papillary thyroid cancer deaths had the V600E mutation in the BRAF gene, confirming that a positive V600E mutation in the BRAF gene is associated with increased mortality in patients with papillary thyroid cancer.
Thus we can see the scenario and significance of the application of BRAF gene mutation testing for thyroid nodule malignancy.
Application in combination with fine needle aspiration cell biopsy of the thyroid. It is a complementary test for the assessment of the cancer potential of the sample, thus assessing the need for thyroidectomy in patients with thyroid nodules, improving the diagnostic validity of thyroid fine needle aspiration cytobiopsy, and avoiding unnecessary thyroid surgery and its adverse consequences.
We can say that this is really an exciting advancement in the field of disease detection. It’s like how pregnant women who used to have to undergo amniocentesis can now easily undergo a prenatal non-invasive maternal screening, and how patients with thyroid nodules can now easily undergo a BRAF mutation test for the degree of thyroid nodule malignancy!