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| FOR IMMEDIATE RELEASE Sept. 19, 2003, 11:45 a.m. EDT |
Media Contact: Melanie Caudron melanie.caudron@verizon.net |
Gene Profiling May Greatly Improve Diagnosis of Thyroid Cancer, Improving Treatment for Cancer and Avoiding Surgery for Others
(PALM BEACH, FLA., Sept. 19, 2003) - Gene profiling shows promise in more
accurately assessing benign from cancerous thyroid nodules, according
to a study being presented today at the 75th Annual Meeting of the American
Thyroid Association.
The thyroid nodule is the most common endocrine problem in the United
States. The chances are one in 10 that a person will develop a thyroid
nodule. Although thyroid nodules are very common, fewer than one in 100
harbor a thyroid cancer. A diagnosis of thyroid cancer is made on the
basis of a biopsy, called fine needle aspiration (FNA), of a thyroid nodule
or after the nodule is removed during surgery.
The current study looked at papillary (PTC) and the follicular variant
of papillary thyroid cancer (FV-PTC). Papillary is the most common type
of thyroid cancer, making up about 70 percent to 80 percent of all thyroid
cancers. This cancer can occur at any age. Both forms of this cancer are
capable of metastasizing, or spreading to other parts of the body. Follicular
thyroid tumors, in particular, are a diagnostic dilemma for endocrinologists
and endocrine surgeons. Although most are benign, approximately 20 percent
will be malignant. The problem is that FNA cannot distinguish between
benign and malignant. Standard treatment for malignant tumors is removing
the thyroid gland and postoperative radioactive iodine.
For several years, researchers at Weill Cornell Medical College in New
York City have been interested in molecular markers of cancer, which would
enhance the ability to make this distinction. Previous attempts using
single or even several markers were unsuccessful, and these researchers
turned to gene profiling to try to make this distinction. Their work leading
to the current findings was published in the May 2003 issue of Clinical
Cancer Research.
In the current study, the researchers analyzed the gene expression patterns
of seven PTCs, seven FV-PTCs, and 20 benign tumors. Distinct gene profiles
were found for each group, with the PTC and FV-PTC groups having a well-defined
gene expression profile compared to the benign samples. The sensitivity
for a diagnosis - percentage of cancer cases detected - was 93 percent,
and the specificity - indicating reliability of positive results - was
100 percent. Both measures are important for the accuracy of a test, with
a good result indicating that a test can detect cancer when it is present
without misdiagnosing too many benign nodules as cancerous.
"At this point, we have just laid the groundwork for bringing these findings into clinical practice," said Thomas J. Fahey III, MD, senior author of the study and chief of the Section of Endocrine Surgery at Weill Cornell Medical Center. "We are now proceeding to apply these findings to samples obtained by fine needle aspiration. The potential clearly exists to make diagnosis of thyroid nodules more accurate, which may result in either more definitive initial surgery or possibly permit avoiding surgery altogether."
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