SERUM ADIPONECTIN AND INSULIN-LIKE GROWTH FACTOR 1 IN PREDOMINANTLY FEMALE PATIENTS WITH THYROID CANCER: ASSOCIATION WITH THE HISTOLOGIC CHARACTERISTICS OF THE TUMOR

Abstract

Objective: Insulin-like growth factor (IGF)-1 and adiponectin have been proposed to contribute to the pathogenesis of different malignancies. However, data regarding their association with histologic characteristics of thyroid cancer are scarce. The main aims of the present study were the comparative evaluation of IGF-1, IGF-binding protein 3 (BP3), and adiponectin serum levels between different histologic types of thyroid cancer, as well as within specific histologic characteristics of the tumors.

Methods: A total of 179 thyroid cancer patients (126 [70.4%] women) were recruited. A total of 129 (72.1%) had papillary thyroid carcinoma (including variants), 26 had follicular thyroid carcinoma (14.5%), and 24 had medullary thyroid carcinoma (13.4%). Parameters from history, physical examination, and thyroid histology were selected. Serum adiponectin, IGF-1, and IGF-BP3 were measured in fasting morning samples.

Results: IGF-1, IGF-BP3, and adiponectin levels were similar among different histologic types of thyroid carcinoma, with a trend towards higher IGF-1 and IGF-BP3 levels in patients with intrathyroid invasion, compared to those without. In addition, ratios of IGF-1 to adiponectin (P = .012) and IGF-1 to (adiponectin × IGF-BP3) (P = .003), as well as type 2 diabetes (P = .001), were positively associated with tumor size.

Conclusion: Although IGF-1, IGF-BP3, and adiponectin were not separately different between groups or within specific histologic lesions, when they were combined to produce IGF-1 to adiponectin and IGF-1 to (adiponectin × IGF-BP3) ratios, they were independently associated with tumor size. Future prospective studies are needed to evaluate whether these ratios could serve as prognostic markers of thyroid tumor aggressiveness.