THURSDAY, Oct. 12, 2006 (HealthDay News) -- Researchers say they've developed a sensitive new early detection test for thyroid cancer.
If such a test is proven to be practical, it could help diagnose the growing number of people with thyroid cancer before it spreads (metastasizes) to lymph nodes and other body sites. As with all cancers, early detection of thyroid tumors is the key to a cure.
"Our research aims to simplify diagnosis and follow-up care by identifying a reproducible biomarker that correlates directly with the presence or progression of thyroid cancer," lead researcher Dr. Andrew J. Martorella, from the Memorial Sloan-Kettering Cancer Center in New York City, said in a prepared statement.
The paper was expected to be presented Thursday at the annual meeting of the American Thyroid Association, in Phoenix.
The thyroid is a butterfly-shaped gland located beneath the voice box that produces thyroid hormone, which the body uses to regulate growth and metabolism.
This year, about 30,180 new cases of thyroid cancer will be diagnosed in the United States. Cancer experts are particularly concerned about the 2 percent rise in thyroid cancer incidences each year. Almost two-thirds of these cancers are found in people between the ages of 20 and 55, according to the American Cancer Society.
In the study, the Sloan-Kettering researchers evaluated 200 healthy people and 60 people with metastatic thyroid cancer. They used mass spectroscopy to measure and identify multiple peptides -- types of proteins -- in the blood.
Using this technique, Martorella's group was able to identify the peptide pattern, or "fingerprint," that signals thyroid cancer. This thyroid-cancer-specific serum peptide profile correctly classified samples as having thyroid cancer or not with 95 percent sensitivity and specificity.
That means that only 5 percent of tests would miss thyroid cancer, and only 5 percent would diagnose thyroid cancer when it wasn't there, the research team said.
"The results of the study are remarkable," Martorella said. "This serum peptide profile has the potential to serve as a molecular fingerprint that distinguishes metastatic thyroid cancer from normal healthy patients, allowing physicians the ability to diagnose thyroid cancer earlier."
One expert agreed.
"I think this is a great study which will enable clinicians to identify a subset of thyroid cancer with metastasis," said Dr. Ashraf Khan, a professor of pathology at the University of Massachusetts Medical School. "In this era of proteomics and genomics, it is nice to see a study like this, using this modern technology in medicine," he added.
Accurate diagnosis is crucial to the appropriate surgical management of these patients, Kahn added.
But he said that "one limitation that I see with the study is not including a group of thyroid cancer [patients] without metastasis and also not having information about the subtypes of these tumors, which is very important in the management of thyroid cancer."
Another expert said similar tests might work for other malignancies.
"This is part of a larger effort in trying to find blood tests that can distinguish cancer patients from normal people," said Dr. Len Lichtenfeld, the deputy chief medical officer at the American Cancer Society. "This test has to be verified, and it has to be determined how practical it will be," he added.
Lichtenfeld believes the approach will eventually lead to screening tests for cancer, especially in high-risk patients.
More information
For more on thyroid cancer, head to the U.S. National Cancer Institute.
