INTRODUCTION
Obesity is a well-established risk factor for numerous diseases, including different types of cancer [1, 2]. Various studies and meta-analyses have observed an increase in the incidence of differentiated thyroid cancer in overweight and obese individuals [3]. Additionally, it has been suggested that obesity is associated to more aggressive forms of papillary cancer [4], to more advanced stages at diagnosis [5] and to higher rates of disease persistence after treatment [6]. However, these associations have not been replicated in other studies [7 ].
Ultrasound screening of thyroid cancer is not recommended in asymptomatic individuals with no specific risks for the disease [8], however, some controversy exists about the benefits and risks of the screening in high risk populations such as radiation exposure [9, 10] and autoimmune thyroid diseases [11]. Obesity may be also considered a risk factor for thyroid cancer [12], and although the screening of thyroid cancer in obese individuals is not considered justified [13], data about the feasibility of early detection of thyroid cancer by systematic ultrasound assessment and its effects on the prognosis of thyroid cancer in patients with obesity are lacking [13].
In order to justify a specific cancer screening approach, it must be demonstrated that it is beneficial, that it lacks of significant harm and that it is cost-effective [14]. Recently, Cham et al [15], evaluated the cost-effectiveness of US screening of thyroid cancer in obese individuals. In their study, using data from published reports and US costs, the authors concluded that US screening of thyroid cancer in selected obese patients with risk factors (family history of thyroid cancer, radiation exposure, Hashimoto’s thyroiditis, and/or elevated thyrotropin (TSH)) was cost-effective. However, the study was based on published reports and has not been experimentally validated in actual obese patients.
The objective of the current study is to evaluate if a strategy of US screening of thyroid nodules in obese patients with risk factors, can be validated in a real clinical setting.