What the diagnosis means
Papillary and follicular thyroid cancers (together "differentiated" thyroid cancer) make up the large majority and usually grow slowly. Medullary thyroid cancer arises from a different cell type, can run in families (RET gene), and is monitored with calcitonin. Anaplastic thyroid cancer is rare and aggressive. Diagnosis is by ultrasound and fine-needle aspiration; staging takes age and spread into account.
Where medical oncology fits
Thyroid cancer is treated mainly by endocrine surgeons, nuclear medicine (radioactive iodine) and endocrinologists (thyroid hormone replacement and suppression, long-term monitoring with thyroglobulin). Medical oncology becomes involved when:
- differentiated thyroid cancer has spread and no longer takes up radioactive iodine ("iodine-refractory") and is progressing — targeted tablets (multikinase inhibitors, or selective inhibitors for RET or NTRK alterations) are then used;
- medullary thyroid cancer is advanced — RET-targeted tablets are highly effective for RET-mutant disease;
- anaplastic thyroid cancer is diagnosed — urgent combined treatment with surgery where possible, radiation, chemotherapy and, for BRAF-mutant tumours, targeted therapy.
Many patients with advanced but slow-growing disease do not need drug treatment immediately; watchful monitoring is often the right decision.
Testing that matters
For advanced disease, molecular testing for RET, BRAF, NTRK and related alterations determines whether a selective targeted drug is available. Germline RET testing is recommended for everyone with medullary thyroid cancer, because of implications for family members.
What to expect
Targeted tablets are taken daily for as long as they work; blood pressure, diarrhoea, hand-foot skin reaction, tiredness and thyroid hormone levels are monitored. Scans every few months assess response.
Questions to ask
- Which type of thyroid cancer do I have and what is the expected course?
- Do I need radioactive iodine after surgery, and what does my thyroglobulin trend show?
- If the cancer is advanced: is it progressing fast enough to need treatment now?
- Have molecular tests (RET, BRAF, NTRK) been done?
- For medullary cancer: should my family be tested?
Preparing for your consultation
Bring surgical and pathology reports, radioactive-iodine treatment records, thyroglobulin or calcitonin trends, recent ultrasound/CT/PET reports, current thyroxine dose, and a medicine list.