Thyroid cancer treatment almost always starts with surgery and, depending on the type and stage, may include radioactive iodine, hormone therapy, radiation, or targeted drugs. The outlook is overwhelmingly favorable: the five-year survival rate for thyroid cancer caught before it spreads beyond the thyroid is 99.9%, and even cancer that has reached nearby lymph nodes has a 98.1% survival rate, according to National Cancer Institute data.
What your treatment plan looks like depends on the type of thyroid cancer you have (papillary, follicular, medullary, or anaplastic), how large it is, whether it has spread, and your individual risk profile. Here’s what each treatment involves and who it’s typically recommended for.
Surgery: Lobectomy vs. Total Thyroidectomy
Surgery is the first-line treatment for nearly all thyroid cancers. The two main options are removing half the thyroid (lobectomy) or the entire gland (total thyroidectomy). American Thyroid Association guidelines consider lobectomy an acceptable option for small, less aggressive papillary thyroid cancers with no evidence of spread beyond the thyroid or into surrounding tissues. This means that if your tumor is small and confined, you may be able to keep half your thyroid, which can reduce or eliminate the need for lifelong thyroid hormone replacement.
Total thyroidectomy is recommended when the cancer is larger, has aggressive features, or has spread to lymph nodes. For medullary thyroid cancer specifically, guidelines recommend total thyroidectomy along with lymph node dissection, since this type doesn’t respond to radioactive iodine and needs to be removed as completely as possible during the initial operation.
One risk worth knowing about: permanent damage to the nerve that controls the vocal cords occurs in roughly 2.6% of nerves exposed during total thyroidectomy. Temporary hoarseness is more common and usually resolves within weeks to months. Low calcium levels after surgery are also possible, since the parathyroid glands sit directly behind the thyroid and can be disrupted during the procedure.
Active Surveillance for Very Small Cancers
Not every thyroid cancer needs immediate surgery. Papillary thyroid microcarcinomas, defined as tumors smaller than 1 centimeter, can sometimes be monitored with regular ultrasounds and physical exams rather than operated on right away. This approach, called active surveillance, is appropriate when the tiny cancer shows no signs of growing or spreading. If the tumor begins to grow or develops concerning features, surgery can be performed at that point without compromising outcomes.
Radioactive Iodine Therapy
After total thyroidectomy for papillary or follicular thyroid cancer, your doctor will assess whether you need radioactive iodine (RAI) therapy. Thyroid cells naturally absorb iodine, so swallowing a radioactive form of it delivers targeted radiation to any remaining thyroid tissue or cancer cells while largely sparing the rest of your body.
Whether RAI is recommended depends on your risk level. Patients classified as high risk, including those with cancer that invaded surrounding tissue, incomplete surgical removal, distant spread, or large lymph node involvement, are typically treated with RAI. For intermediate-risk patients, such as those with aggressive tumor subtypes or moderate lymph node involvement, RAI may be recommended on a case-by-case basis, with factors like age and the extent of lymph node disease influencing the decision.
Low-risk patients with tumors under 1 centimeter generally do not need RAI. However, if post-surgical blood work shows elevated thyroglobulin levels or ultrasound reveals abnormal findings, RAI may still be considered even in this group. The treatment itself involves swallowing a capsule or liquid, then isolating yourself from others for a few days while the radioactivity decreases. Side effects can include neck tenderness, dry mouth, and changes in taste, most of which are temporary.
Thyroid Hormone Therapy
After a total thyroidectomy, you’ll take a daily thyroid hormone pill for the rest of your life, since your body can no longer produce this hormone on its own. But for thyroid cancer patients, this medication serves a dual purpose. Beyond replacing the missing hormone, taking a slightly higher dose suppresses your body’s production of thyroid-stimulating hormone (TSH), which can fuel the growth of any remaining cancer cells.
For low-risk patients, guidelines recommend keeping TSH in the low-normal range, a modest suppression that minimizes side effects. For patients with a moderate to high risk of recurrence, the target is a TSH level below the normal range, which requires a higher dose. Your doctor will adjust your dosage over time based on blood tests and your cancer’s response to treatment.
External Beam Radiation
External beam radiation, the type delivered by a machine aimed at a specific area of the body, plays a different role than radioactive iodine. It’s used primarily for thyroid cancers that don’t absorb iodine, particularly medullary and anaplastic types. For papillary or follicular cancers, external radiation may be used when the cancer doesn’t respond to radioactive iodine therapy.
This treatment is also used when cancer has spread outside the thyroid to manage symptoms like pain, reduce the chance of recurrence in the neck after surgery, or treat specific areas of spread. Sessions are typically given five days a week over several weeks.
Targeted Drug Therapy
When thyroid cancer is advanced, has spread to distant sites, or no longer responds to radioactive iodine, targeted drugs become the main systemic treatment option. These medications work by blocking specific proteins that drive cancer growth, and the right drug depends on the type of thyroid cancer and its genetic profile.
For Papillary and Follicular Cancers
Two multi-target drugs, sorafenib and lenvatinib, are FDA-approved for progressive differentiated thyroid cancers (papillary, follicular, and Hürthle cell) that no longer respond to radioactive iodine. Cabozantinib also received FDA approval for this group. These drugs block multiple growth signals simultaneously, which makes them broadly effective but also means they carry more side effects than precision-targeted options.
For cancers with specific genetic changes, more precise drugs are available. Selpercatinib and pralsetinib target RET gene fusions and are approved for iodine-resistant differentiated thyroid cancers driven by this mutation. For tumors with NTRK gene fusions, larotrectinib and entrectinib are options.
For Medullary Thyroid Cancer
Medullary thyroid cancer doesn’t absorb iodine, so RAI is never an option. When surgery can’t fully control the disease, vandetanib and cabozantinib are approved for progressive or metastatic cases. More recently, the RET-specific drugs selpercatinib and pralsetinib have shown strong results. In clinical trials, selpercatinib produced tumor shrinkage in 69% of previously treated patients and 73% of treatment-naive patients. Pralsetinib showed similar response rates of 60% and 71%, respectively.
These RET-targeted drugs are notably easier to tolerate than older multi-target options. The most common side effect is high blood pressure, affecting 17 to 21% of patients, and very few patients (2 to 4%) needed to stop treatment because of side effects.
For Anaplastic Thyroid Cancer
Anaplastic thyroid cancer is the rarest and most aggressive form. It grows rapidly and has historically had very poor outcomes, with a median survival of under two months when treated with surgery alone. The current approach combines all available tools: surgery, radiation, and systemic therapy together. Patients receiving this three-pronged treatment had a median survival of 9.1 months, compared to 1.7 months for those receiving less intensive therapy. For anaplastic cancers with the BRAF V600E mutation (found in a significant portion of cases), dabrafenib, a highly specific BRAF inhibitor, is FDA-approved.
Survival Rates by Stage
Thyroid cancer has one of the highest survival rates of any cancer. Based on National Cancer Institute data from 2016 to 2022, the five-year relative survival rate is 99.9% for cancer confined to the thyroid, 98.1% for cancer that has spread to regional lymph nodes, and 48.3% for cancer that has metastasized to distant sites. The vast majority of thyroid cancers are caught at the localized or regional stage, where outcomes are excellent.
These numbers reflect all thyroid cancer types combined. Papillary and follicular cancers, which account for the large majority of cases, tend to have the best outcomes. Medullary thyroid cancer carries a somewhat lower survival rate, and anaplastic thyroid cancer, though extremely rare, has the poorest prognosis. The specific type, stage, and genetic characteristics of your cancer all factor into your individual outlook and treatment plan.