INTRODUCTION Thyroid cancer is a relatively rare tumor but is the most common endocrine neoplasm worldwide and has increasingly become a public health problem over the past two decades [1]. In recent years, the incidence of thyroid cancer has increased at an alarming rate, especially in developed countries. Thyroid cancer is the tenth most common cancer in Canada [2]. Furthermore, the incidence rate of thyroid cancer is increasing faster than any other cancer in Canada [3, 4]. Typically, most forms of thyroid cancer (TC) have been treated by surgery, conventional radiotherapy, and chemotherapy. However, these therapies fail to treat the more invasive forms of this cancer. Recent discoveries of the genetic and molecular pathways involved in TC have uncovered possible new therapeutic targets. The thyroid is an endocrine gland located in the front of the neck, above the central trachea and below the larynx. Within the hypothalamic-pituitary-thyroid axis, thyrotropin-releasing hormone (TRH) stimulates the secretion of thyroid-stimulating hormone (TSH) from the anterior pituitary [5]. TSH then acts on the thyroid gland which releases the iodine-dependent hormone thyroxine (T4) and triiodothyroxine (T3) to control physiological functions such as metabolism, heart rate, blood pressure and body temperature [5]. Etiology There are several risk factors for TC, including patient history, family history, genetic factors, age, gender, and environmental factors such as exposure to ionizing radiation and iodine deficiency [5, 6]. During the first 20 years of a person's life, exposures to ionizing radiation can be particularly harmful to the thyroid. This radiation generates free water or oxygen radicals that directly… middle of paper… the initial effects of the drug diminish over time as alternative pathways compensate. Overcoming these mechanisms of resistance to KI is the next step to prolong the effects of targeted therapies. Fortunately, the understanding of epigenetic mechanisms such as histone modifications or RNAs has been significantly advanced in recent years and there is hope that they could be employed in the treatment of thyroid cancers. These advances have been accompanied by challenges in clinical trials. In addition to the fact that clinical sample sizes are generally very small, experimental biomarkers and clinical endpoints have been controversial in the study of thyroid cancers. A better understanding of the different mechanisms has helped researchers make a breakthrough in the management of thyroid cancers. It remains positive to see whether new treatment combinations could increase long-term survival for thyroid cancers.