ABSTRACT
Thyroid cancer (TC) is a relatively uncommon cancer; however, there has been a recent rise in the incidence. High-resolution ultrasound (US) imaging of the neck and increased diagnosis of micropapillary cancer in incidental thyroid nodules picked up on imaging are the main reasons. TC is the most common malignancy in endocrine surgery. Papillary TC is the most common differentiated TC (DTC) and seen in iodine-sufficient areas. Follicular and Hürthle cell cancer are less common and second in frequency and occur in iodine-deficient areas. DTC are managed initially by surgery followed by radioactive iodine therapy in selected patients and thyroid-stimulating hormone (TSH) suppression. Long-term survival is excellent in DTC. A total of 10- and 30-year survivals are in more than 98 and 90%, respectively. Risk of recurrent disease is seen in 20–30% patients over 30- to 40-year follow-up and the risk of recurrence linked to disease-specific survival but is true only in older patients (more than 55 years). So, it is very important to identify the patients who are at an increased risk of recurrence. DTC patients are categorized into low, intermediate and high risk for recurrence after initial surgery depending on various demographic, surgical and tumor factors. The follow-up is planned in individual patients on the basis of risk category. Patients are followed up by physical examination, thyroglobulin (Tg) and anti-Tg antibody measurements and radioiodine scan and neck US done at appropriate intervals depending upon the risk category. Further after adjuvant treatment, patients are categorized on the basis of response to therapy as having an excellent, biochemically incomplete and structurally incomplete or indeterminate response. Level of thyroxine suppression is based on the category of response. During follow-up, a high-risk patient may become low risk or intermediate risk may progress to high risk, and this is termed as ongoing risk stratification or delayed risk stratification.
