Testing thyroid nodules for galectin-3 may reduce unnecessary thyroid surgeries

A galectin-3 test may be a complementary diagnostic test to fine-needle aspiriation for indeterminate follicular nodules, according to findings from a recent study.

Researchers from Italy analyzed 465 follicular thyroid proliferations to determine the effect of galectin-3 expression analysis and distinguish between benign and malignant nodules, classified as indeterminate after fine-needle aspiration. They used a purified monoclonal antibody to galectin-3, biotin-free immunocytohistochemical assay and morphological and phenotypic analyses of fine-needle aspiration-derived cell-block preparations, according to the abstract.

Of the 465 preoperative fine-needle aspiration samples, 331 (71%) were negative for galectin-3 expression. Further, 280 (85%) of the negative lesions were benign and 101 (75%) were confirmed malignant.

The galectin-3 method produced good overall sensitivity (78%) and specificity (93%), with an estimated predictive value of 82% and negative predictive value of 91%. Most patients (88%) with follicular thyroid nodules were correctly classified preoperatively by the galectin-3 test but nearly one-quarter (22%) were missed by this method.

Based on findings from this prospective multi-center study, the galectin-3 test may be successful in diminishing unnecessary thyroid surgeries, according to the researchers. However, the method may potentially miss a number of galectin-3 negative cancers. – by Katie Kalvaitis

Lancet Oncol. 2008;doi:10.1016/S1470-2045(08)70132-3.

This study, along with others, underscores that galectin-3 alone can’t be used to decide which patients with thyroid nodules should be operated on. Nonetheless, galectin-3, in combination with fine-needle aspiration and other tumor markers, may ultimately help physicians make decisions about recommending surgery for some patients with nodular thyroid disease.

– Jeffrey Garber, MD

Endocrine Today Editorial Board member