Papillary Thyroid Cancer
Papillary Thyroid Cancer (PTC) is the most common type of thyroid cancer, representing up to 85% of all thyroid cancers. It is often well-differentiated and slow growing cancer with very good prognosis. It is more common in females with 3:1 ratio. PTC can occur at any age, including childhood, but it is most common after the age of 30. Most thyroid cancers present without any symptoms and are discovered incidentally on neck ultrasound. Some cancer present with thyroid lump or nodule or neck lumps. Very rarely person can present with voice changes or metastatic disease. Features that should raise a suspicion of thyroid cancer are: rapidly enlarging thyroid lump, enlarged neck lymph nodes, unexplained hoarseness of voice, family history of thyroid cancer, history of irradiation and child with thyroid nodule.
Prognosis of papillary thyroid cancer is very good, with overall 10 year survival over 93%. The prognosis depends on size of the cancer, presence of distant metastases (bone, lungs etc rather than lymph node), age at diagnosis and completeness of excision.
Treatment of PTC usually involves surgery. Depending on the size of cancer, this may consist of hemithyroidectomy (removal of only affected thyroid lobe) or total thyroidectomy (removal of whole thyroid gland). If lymph nodes are involved, then these are also removed. There is still controversy in endocrine surgical community whether non-involved lymph nodes in the central neck should be removed (level 6 dissection). Radioiodine treatment, in addition to surgery, may also be recommended in case PTC has more aggressive features. Chemotherapy is often not required and is not very effective in these cancers.
Follow-up usually consists of regular examinations. If you have had total thyroidectomy then you will need regular monitoring of thyroglobulin and anti-thyroglobulin antibodies in the blood. If you have had hemithyroidectomy, then this blood test is not possible to be performed as part of monitoring for thyroid cancer.
Follicular Thyroid Cancer
Follicular Thyroid cancer id second most common cancer and representing up to 15% of all thyroid cancers. Minimally invasive follicular thyroid cancer may be hard to distinguish from follicular adenoma and it is not possible to distinguish on Needle biopsy alone, surgery is required to make this diagnosis. Diagnosis is made on presence of capsular or vascular invasion.
Follicular thyroid cancer does not routinely spread to neck lymph nodes. It usually spreads to bone or lungs.
Treatment usually consists of total thyroidectomy. If only hemithyroidectomy has previously been performed, then completion thyroidectomy is often advised. Surgery is often followed by radioiodine treatment. Chemotherapy is often not required and is not very effective in these cancers.
Follicular thyroid cancer usually has slightly worse prognosis then PTC and overall 10 years survival is 85%. Follow-up usually consists of regular examinations and regular monitoring of thyroglobulin and anti-thyroglobulin antibodies in the blood.
Hurtle Cell Thyroid Cancer
Hurtle cell thyroid cancer is unusual and relatively rare cancer of thyroid gland. It is considered a variant of follicular thyroid cancer.
Medullary Thyroid Cancer
Medullary thyroid cancer (MTC) makes up to 3% of all thyroid cancer cases. It originates from parafollicular thyroid cells which produce hormone calcitonin. These cancers are often associated with RET genetic mutation and this mutation may be inherited. Medullary thyroid cancer can be associated with other cancers and form part of the syndrome called MEN2 (multiple endocrine neoplasia type 2). If you are diagnosed with this type of cancer, then you should be offered a referral to genetic services for genetic testing.
Medullary thyroid cancer often presents with diarrhea and flushing, rather then thyroid nodules. It is aggressive type of cancer and it may also present with metastases. Diagnosis with FNA may be challenging, but performing calcitonin staining is usually diagnostic.
Treatment usually consists of total thyroidectomy with unilateral or bilateral neck lymph node dissection. Extensive surgery can be effective when the condition is detected and treated early, but the risk of recurrence remains high, particularly in patients with lymph node disease. Treatment with radiotherapy may be offered as well. Chemotherapy may be offered in metastatic disease.
Prognosis depends on stage, but overall 10-years survival is 75%. 5-year survival for stage I is 100%, stage II 98%, stage III 81% and Stage IV 28%.
Follow-up usually consists of regular examinations and regular monitoring of calcitonin and CEA in the blood. Calcitonin doubling time (how long it takes for calcitnon level to become double) is best in predicting the survival in MTC.
Poorly Differentiated Thyroid Cancer
Poorly Differentiated Thyroid Cancer (PDTC) is a rare form of thyroid cancer that is often aggressive. It is associated with high risk of cancer recurrence, spread to lung and or bones and death. Often these cancers are not sensitive to radioiodine treatment.
Treatment involves total thyroidectomy and central node dissection. If other lymph nodes are involved, then neck dissection is also performed. Tumours are checked for their susceptibility for radioiodine and if found to be susceptible, then they are treated with radioiodine as well.
Follow-up usually consists of regular examinations and regular monitoring of thyroglobulin in the blood.
Anaplastic Thyroid Cancer
Anaplastic Thyroid Cancer is very rare form of thyroid cancer that has a very poor prognosis. It is one of the most aggressive cancers. These cancers present with rapidly enlarging thyroid gland. They often invade into surrounding tissues including windpipe (trachea). At presentation these cancers have often metastasized.
Prognosis is poor 5-year survival is less then 5%. Treatment is usually palliative. If this cancer is resectable, then surgery may be performed. The radiotherapy has also been used as well as chemotherapy. Despite everything, survival is still poor.