Researchers of the University of Texas (UT) and the Baylor College of Medicine They have developed a new preoperative test for thyroid cancer that is faster and about two-thirds more accurate than the diagnostic tests doctors currently use, as published in the journal ‘Proceedings of the National Academy of Sciences’.
Although further validation will be necessary before it can be used clinically, the new metabolic thyroid test is promising to prevent thousands of unnecessary thyroid extractions every year, such as the partial extraction to which the UT graduate student, Amanda Helms, was subjected , due to an inconclusive test. “All that uncertainty was stressful,” says Helms.
“If we could prevent people from undergoing surgery that they do not need and allow them to have a more accurate diagnosis, we can improve treatment for patients and reduce the costs of the health care system,” said Livia S. Eberlin, assistant professor of Chemistry and Diagnostic Medicine at the University of Texas and co-principal investigator.
For her part, Rachel DeHoog, a graduate student who worked on the study, adds: “It is also very important the ability to be certain in the diagnosis for a patient with the possibility of having cancer.”
Each year in the United States they diagnose about 52,000 new cases of thyroid cancer and unfortunately, the test used for diagnosis, called fine needle aspiration (FNA), is inconclusive about 1 in 5 times. When a pathologist cannot confirm the presence of cancer, the patient can receive a follow-up genetic test that can produce false positive results.
Given the uncertainties, doctors often recommend removing part or all of the thyroid, the neck gland that produces hormones that control the body's metabolic rate, as well as cardiac and digestive function, muscle control, brain development, Mood and bone maintenance. Thousands of patients every year undergo surgery so that after it is proven it was not necessary.
Using a technology called mass spectrometry imaging, the new metabolic thyroid test identifies metabolites produced by cancer cells that act as a kind of diagnostic fingerprint.
The researchers worked on the identification of these diagnostic metabolic traces for more than two years using 178 patient tissues before beginning a pilot clinical study. During the clinical study, 68 new patients were evaluated, almost a third of whom had received inconclusive FNA results.
The new metabolic thyroid test showed a false positive only about 1 time out of 10 and could have prevented 17 patients in the study from undergoing unnecessary surgery.
Improved accuracy would avoid those unnecessary surgeries, many of which lead patients to need hormone replacement therapy for the rest of their lives or to face other consequences of total or partial removal of their thyroid.
This is the case of Helms, a graduate student in Chemistry at the UT, who
He learned a few years ago as an undergraduate student at the age of 19 that thyroid lumps indicated possible cancer. When his FNA biopsy was inconclusive, a doctor recommended removing the right half of the thyroid.
This recommendation was followed by a difficult surgery and a complicated recovery, although he soon received the news that pathologists did not detect cancer in the excised tissue. Helms says the new test could prevent others from going through what she went through.
“Many fewer people would have to undergo surgery unnecessarily, which saves them time, money and recovery,” he says. And it would also eliminate uncertainty. ”
For his part, James Suliburk, researcher and head of Endocrine Surgery at Baylor College of Medicine, in Houston, collected FNA biopsies of the patients involved in the study and implemented the technology in a pilot trial to demonstrate the accuracy of the new test.
“With this next-generation test, we can provide thyroid cancer diagnoses faster and more accurately than current techniques – says Suliburk, who operates at the Baylor St. Luke Medical Center and Harris Hospital Ben Taub Health System -. We can do this analysis directly on the FNA sample and much faster than the current process, which could take between three and 30 days. ”
The team is now preparing to begin a two-year validation study on FNA of about one thousand new patients from the United States, Brazil and Australia. If the results are maintained, they expect the technology to be translated into the clinic as a routine diagnostic tool.