The incidence of thyroid cancer has increased exponentially over the past few decades in Australia (and other countries) but mortality has not increased. This increase in incidence is above that seen in any other cancer (age and sex adjusted). Recognised risk factors for thyroid cancer include a family history and exposure to ionising radiation (eg following the Chernobyl nuclear accident, and also following scatter radiation from cranial irradiation given to treat childhood leukemia). However most people have no identifiable cause.
The commonest type of thyroid cancer is papillary. Thyroid papillary cancer has an excellent prognosis with an overall 5-year survival rate of 96-97% and 10-year survival rate of 93%. Much of the rise in thyroid cancer is attributed to increased surveillance by various forms of imaging eg ultrasound and increased detection of microcarcinomas (<1cm). Whilst papillary thyroid microcarcinomas (stage I or II) have close to a 100% 5-year survival rate, a high proportion have bilateral disease, multi-focality and cervical lymph node metastases. These factors increase the risk of local recurrence but not mortality. Adjunctive therapy with radio-active iodine (RAI), usually administered after thyroidectomy, will be discussed. The most recent recommendations are that RAI therapy may not be needed in patients with the lowest risk of recurrence.
Cases of thyroid cancer, particularly in young people, will be presented and discussed.