MONDAY, May 19 (HealthDay News) -- Testing thyroid nodules for the presence of a lectin molecule called galectin-3 could help improve identification of nodules with cancer and reduce the number of unnecessary surgeries, according to an Italian study.

The standard method of determining whether a nodule is malignant is to examine cells extracted by fine-needle aspiration. About 85 percent of thyroid nodules removed by surgery turn out to be benign.

Galectin-3 is not normally present in thyroid cells. When it is present, it can block cell death, leading to the development of cancer, researchers report.

In this study, researchers at St. Andrea Hospital in Rome tested galectin-3 expression in 465 people who were scheduled for surgery to remove thyroid nodules. After the nodules were removed, the final histological results that determined whether they were cancerous or benign were compared to the findings from the galectin-3 testing done before the surgery.

Galectin-3 was not expressed in 331 (71 percent) of 465 nodules. Of those galectin-3-negative nodules, 280 (85 percent) were benign, 29 (9 percent) were cancerous, and the remainder were borderline.

The researchers concluded the sensitivity of the galectin-3 test was 78 percent, the specificity was 93 percent, the positive predictive value was 82 percent, and the negative predictive value was 91 percent.

The findings were published online Monday and in the June issue of The Lancet Oncology.

"The galectin-3 method proposed here does not replace conventional FNA-cytology, but represents a complementary diagnostic method for those follicular nodules that remain indeterminate. The correct approach for this preoperative characterization of thyroid nodules always needs careful multidisciplinary assessment of each patient, according to published guidelines," the study authors wrote.

More information

The American Cancer Society has more about thyroid cancer diagnosis.

-- Robert Preidt

SOURCE: The Lancet Oncology, news release, May 19, 2008

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