At UCSF we support thyroid cancer biopsies, but new research shows evidence that thyroid cancer biopsy standards should be updated and simplified to reduce unnecessary procedures. Based on the findings of the study, patients should only be biopsied when imaging reveals a thyroid nodule that is more than two centimeters in diameter and completely solid or one that contains Microcalcification (tiny calcium flecks.) The recommendation stems from a retrospective published in JAMA Internal Medicine.
The research team analyzed the records of 8,806 patients who underwent 11,619 thyroid ultrasound examinations, but did not have a thyroid cancer diagnosis at the time of the ultrasound. Ultrasounds were performed for multiple reasons, including abnormal thyroid function tests, physicians’ suspicions or CT/ MRI exams revealing at least one nodule.
The research revealed that while 97 percent of the patients who did have thyroid cancer had at least one nodule, 56 percent of patients without cancer had nodules, too. But most notably, more than 98 percent of detected nodules in the study were benign, not malignant cancer.
The study comes down to too many biopsies for very low risk patients. Compared with other existing guidelines, many of which are complicated to apply, following these simple, evidence-based guidelines would substantially decrease the number of unnecessary thyroid biopsies in the United States. Currently, we’re doing far too many thyroid biopsies in patients who are at very low risk of having thyroid cancer.
Based on our findings, there are three significant ultrasound findings that indicate an increased chance of thyroid cancer:
· A nodule with a diameter greater than two centimeters
· A nodule that is solid, rather than cyst-like
If you have all three characteristics together, it’s almost certainly cancer. On the other hand, without these characteristics, you are at very low risk – less than one-half of 1 percent – and a biopsy is not necessary. Nor is continued surveillance. In this instance, it’s important to start doing diagnostic tests and procedures more selectively and prudently, as there are harms to doing unnecessary tests and procedures.
For more information on this retrospective and its findings, please see here.
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