Obesity and Thyroid Cancer Risk: An Update

Abstract

Thyroid cancer (TC) is the most common endocrine malignancy worldwide and its incidence has increased dramatically in recent years. In parallel, the prevalence of overweight and obesity has also increased, suggesting a possible link between these two diseases. Indeed, low-grade chronic inflammation, altered cytokine levels, insulin resistance, oxidative stress, and hormonal changes that occur in obese patients are all factors that contribute to the occurrence and growth of TC. In this review, the most recent evidence supporting the potential role of the mechanisms linking obesity to TC will be discussed.

Keywords: cytokines; estrogens; insulin; insulin resistance; obesity; overweight; oxidative stress; risk factors; thyroid carcinoma.

Figure 1

Schematic representation of the main factors linking obesity to thyroid cancer. Diet is the most important factor in the development of obesity, but also plays an important role in influencing TC risk, either directly (i.e.,: iodine deficiency, endocrine disruptors [8]) or through indirect mechanisms (i.e.,: certain pro-inflammatory foods [39]). Obesity promotes additional molecular effects that contribute to induction, growth, and proliferation of TCs. IGFs: insulin-like growth factors.