Staging & Prognosis of Thyroid Cancer
In general terms the prognosis of thyroid cancer (for the common types of thyroid cancer) is excellent. Your doctors may describe your thyroid cancer using the TNM (7) staging system.
T describes the size of the tumour. There are four main stages ranging from T1 – T4.
N describes whether the cancer has spread to the lymph nodes close to the thyroid gland. There are two stages: in N0 there is no sign of cancer in the lymph glands; in N1 there are cancer cells in the lymph glands.
M describes whether the cancer has spread to another part of the body, such as the lungs or the bones (secondary or metastatic cancer). There are two stages: M0 is where there are no metastases; M1 is where there are metastases.
For papillary and follicular thyroid cancer the prognosis is most favourable for those under the age of 45 years. Female patients have a slightly better cure rate than male patients, and the long term cure rates are between 85-95% depending on size of tumour and presence of any neck node spread (see above).
In young patients, even those with spread of their tumour to other organs have a high cure rate. Older patients have a slightly worse outcome from these types of thyroid cancer, but all are potentially associated with long term survival and cure.
For medullary thyroid cancer, early diagnosis and complete surgical removal of the tumour is imperative for long term cure. However even patients with advanced disease or those not suitable for surgery can have their disease controlled for many years, and the tumour is for the vast majority of patients an indolent disease.
Anaplastic cancers have the worst outcome of all the different types of thyroid tumours. Treatment with radiotherapy can slow the growth of these tumours, but very few patients achieve a long term cure.