Endocrine Abstracts

Background: The role of circulating Galectin-3 as a potential biomarker of malignancy in thyroid disease remains inconclusive. In a previous pilot study we reported a significant difference between serum Gal-3 levels in papillary thyroid carcinoma (PTC) patients and those with benign pathology, but no association with tumor aggressiveness.

Aim: We measured serum Gal-3 levels in a larger series of patients submitted to thyroidectomy, in order to assess its value as possible biomarker in PTC.

Patients and methods: We retrospectively investigated serum Gal-3 in 190 patients, aged 49.09±13.55 years, 151 women (79.5%) and 39 men (20.5%). Patients, who gave their informed written consent, were divided in two groups, based on the pathology report: benign disease (N=88) and PTC (N=102). The thyroid cancer group was analyzed according to pathological stage, histological subtype, multifocality, invasion and tumor size. Sera were collected before surgery. Gal-3 was measured by Elisa, using a monoclonal antibody specific for human Gal-3 (R&D Systems). The study was approved by Ethics Committee of the Institute.

Results: According to the pathology tumor stage (T1-T4), the thyroid cancer patients were divided in four subgroups: PTC1 (N=35), PTC2 (N=21), PTC3 (N=41) and PTC4 (N=5). We found no significant difference in serum Gal-3 levels between cancer and non-cancer patients (9.98±2.66 ng/ml vs 8.11±2.81 ng/ml, P=NS), or between different PTC stages (PTC1:8.01±2.39 ng/ml vs PTC2:7.66±2.26 ng/ml vs PTC3: 8.36±2.95 ng/ml vs PTC4:9.57±2.78 ng/ml, P=NS for all comparisons). Serum Gal-3 did not discriminate between unifocal vs multifocal PTC or invasive vs non-invasive tumors. There was no correlation between serum Gal-3 and tumor size (r=0.05).

Conclusion: The analysis of a large series of patients with tumor thyroid disease, using a highly specific Gal-3 antibody, revealed no difference in serum Gal-3 between cancer and non-cancer patients and no correlation with tumor aggressiveness, suggesting no benefit in its use as a diagnostic test in thyroid cancer.