Thyroid Cancer: What Patients Should Know

Under­stand­ing the diag­nosis

Thyroid cancer begins when cells in the thyroid gland become malignant. Many thyroid cancers are found after a thyroid nodule is noticed on an exam or imaging study. Thyroid nodules are common, and most are benign.

The main thyroid cancer types are papillary, follicular, medullary, and anaplastic. Papillary and follicular cancers are often grouped as differentiated thyroid cancers. They are the most common thyroid cancers and are often treatable, especially when found early.

Medullary thyroid cancer starts in different thyroid cells and is sometimes linked to an inherited RET gene change. Anaplastic thyroid cancer is rare and aggressive. These types need a care team experienced with their specific risks and treatment options.

Evaluation and risk context

Evaluation usually includes a neck exam, thyroid blood tests, ultrasound, and fine-needle aspiration when biopsy is needed. Ultrasound helps describe the thyroid nodule and nearby lymph nodes. Learn what a thyroid ultrasound shows and what TI-RADS means. A biopsy result may be benign, indeterminate, suspicious for cancer, or malignant.

For a broader overview of how blood tests, ultrasound, and biopsy fit together, visit Testing and Diagnosis.

After cancer is diagnosed, the next question is risk context. A clinician considers the cancer type, size, whether it appears limited to the thyroid, whether lymph nodes are involved, whether there is spread outside the neck, and what the pathology report shows.

Treatment planning

Surgery is a common treatment for thyroid cancer. Depending on the situation, surgery may remove one thyroid lobe, called lobectomy, or the whole thyroid, called total thyroidectomy. The decision depends on tumor features, findings in the rest of the thyroid, lymph-node findings, and patient preference after discussion with the care team.

Some patients may need radioactive iodine after surgery. Radioactive iodine is used for selected differentiated thyroid cancers, especially when there is higher risk of remaining thyroid cancer cells. It is not used for medullary thyroid cancer.

Thyroid hormone medicine may be used after surgery to replace missing thyroid hormone. In some thyroid cancer plans, the dose is also chosen to lower thyroid-stimulating hormone, or TSH, because TSH can stimulate some thyroid cancer cells.

Local treatment of recurrent neck disease

When differentiated thyroid cancer remains or returns in a cervical lymph node, the plan depends on the size and location of disease, its rate of growth, previous operations, nearby nerves and blood vessels, other sites of disease, medical risks, and patient preferences.

Selected small, stable lymph nodes may sometimes be monitored. Reoperative surgery remains the usual first treatment for most clinically apparent, macroscopic nodal disease when an operation is appropriate.

Before focused ablation, the target should generally be confirmed as cancer and reviewed in the context of the patient's complete cancer evaluation. Treatment requires an experienced clinician and continued surveillance because treating one lymph node does not evaluate or remove an entire lymph-node compartment.

Read the separate ethanol ablation discussion.

Monitoring and follow-up

Follow-up is based on the original cancer risk and how the cancer responds to treatment. It may include physical exams, neck ultrasound, blood tests, and review of symptoms. Some patients have thyroglobulin testing after treatment for differentiated thyroid cancer. Patients with medullary thyroid cancer may have calcitonin and CEA testing.

Monitoring is not the same for everyone. A person with a small, low-risk cancer and reassuring follow-up tests may need less intensive monitoring over time. A person with higher-risk features, persistent disease, or recurrent disease may need closer follow-up and additional imaging or treatment.

Recurrence can happen after thyroid cancer treatment, so patients should keep follow-up appointments and ask their clinician what changes should prompt earlier contact.

Questions to ask your clinician

• What type of thyroid cancer do I have?
• What did my ultrasound and biopsy show?
• Is there any sign that cancer has spread to lymph nodes or outside the neck?
• Would lobectomy, total thyroidectomy, or active surveillance fit my situation?
• Would radioactive iodine be useful for me?
• What follow-up tests will I need after treatment?
• If cancer returns in my neck, would monitoring, reoperation, or focused ablation be appropriate?
• Should I see a thyroid cancer specialist or endocrine surgeon?
• Does my cancer type raise any genetic testing questions for me or my family?