Approach to the Thyroid Cancer Patient with Bone Metastases

Abstract

Thyroid cancer incidence has been increasing for decades in the United States (1, 2). There are known risk factors for thyroid cancer including female gender, advancing age, family history, and radiation exposure, but none of these can fully explain the changing pattern of this disease over such a short period of time. Much of the rise has been attributed to increased medical surveillance, diagnostic imaging, and ultrasound-guided fine-needle aspiration (FNA), but this probably does not explain the entire observed upsurge. With increased evaluation of patients in an asymptomatic stage, it might be expected that the highest rate of increase would be seen in tumors of less than 1.0 cm, but incidence has also been increasing for tumors of any size, especially tumors at least 4 cm among men and women and for distant metastases among men (3). The more frequent diagnosis of late stage disease has led to the rising occurrence of differentiated thyroid carcinoma and bone metastases, even as the initial presentation of disease. It is suspected that a combination of environmental factors, iodine deficiency, and genetic factors (i.e. BRAF mutations) may explain the rising incidence of differentiated thyroid cancer, particularly more aggressive, late stage disease (4, 5).