Thyroid cancer treatment

Thyroid Cancer (TC) Diagnosis and Treatment by the American Cancer Society (ACS 2021)

How is thyroid cancer diagnosed?

Specialist consultation

At the initial consultation with a medical oncologist, the doctor will take a detailed history, ask about your complaints and review your medical history. If any of your family members have had thyroid cancer (medullary form) or pheochromocytoma, you should tell your doctor because you may be at high risk.

Ultrasound

Ultrasound helps doctors examine abnormal nodes to clarify their density and size. An ultrasound can be used to determine if the mass is solid or filled with fluid.

Under the supervision of an ultrasound, doctors can perform tissue sampling for later examination under a microscope. This is especially helpful in cases where the abnormal mass is small.

Radioisotope scan with iodine (I-131)

In some cases, specialists may examine the thyroid using radioactive iodine. The patient is offered the drug in pill form or injected directly into a vein.

The iodine injected is naturally accumulated by the cells of the thyroid gland. So-called “hot” thyroid nodules, which accumulate more iodine than normal cells, are not malignant tumors. Cancerous cells absorb less iodine and look like “cold” nodes when scanned.

The radioisotope scanning method is not specific for diagnosing cancer and is necessary for differential diagnosis of the cancer process with other thyroid diseases.

Chest X-ray

The doctor may order a chest X-ray to see if the tumor has spread to the lungs. This is done if the patient has been diagnosed with follicular thyroid cancer, which is more likely to metastasize to the bones and lungs.

Computed tomography (CT scan)

Computed tomography is an additional diagnostic modality that is less preferable to MRI. However, it may be prescribed to assess the size, localization, and spread of a primary tumor and to track possible lung metastases.

Magnetic resonance imaging (MRI)

MRIs provide high-quality, detailed images of all parts of the body layer by layer. This gives doctors information about the extent to which the tumor has spread beyond the primary location. MRI is often prescribed if you want to evaluate the spread of a tumor into the brain or spinal cord.

Positron emission tomography (PET)

A PET scan can be useful if a thyroid tumor does not absorb radioactive iodine during the examination. In this situation, a PET scan can determine if the cancer has spread to distant organs.

Biopsy and cytogenetic study

When thyroid cancer is suspected, the “gold standard” of diagnosis is a biopsy. During a biopsy, the doctor takes a special thin needle to take a number of cells from a pathological site of the thyroid gland.

In order for the test to be more informative, aspiration of cells is done in several places of the alleged tumor. After which the material is analyzed in a special laboratory. Sometimes the results of the test are not informative, and if the doctor suspects thyroid cancer, a biopsy may be performed repeatedly, or the patient is advised to have the node removed followed by a histologic study.

Specialists may order additional tests on samples taken during the biopsy. The tissue is tested for genetic mutations in the BRAF or RET/PTC genes. Finding mutations makes thyroid cancer much more likely. The presence of mutations in the genes gives doctors information about which targeted (targeted) drugs will be most effective for the patient.

Laboratory blood tests

For thyroid cancer, the following laboratory blood tests may be ordered:

• Thyrotropic hormone (TSH),
• T3 and T4 (thyroid hormones),
• Thyroglobulin,
• Calcitonin,
• Carcinoembryonic antigen (S-CEA).

The results of laboratory blood tests supplement the clinical picture and help doctors tailor a treatment program according to the patient’s current condition and stage of the disease.

How are thyroid cancer treatment methods abroad?

Surgical treatment

Removing a thyroid tumor is the primary treatment for all types of cancer, except for some anaplastic forms. The doctor may suggest one of the following surgeries:

• Lobectomy (removal of one lobe of the thyroid gland). If the tumor has not spread beyond one lobe, a lobectomy is preferable because some patients may not take thyroid hormones permanently after surgery.
• Thyroidectomy. This surgery removes the entire thyroid gland. This is the most common option for surgical treatment.
• Removal of lymph nodes. If the tumor has spread beyond the thyroid gland to the lymphatic system – the doctor performs a total removal of the thyroid gland along with some lymph nodes of the neck. This is to ensure that the cancer does not come back again. Such a phenomenon is called recurrence.

Radioiodine Therapy

Normally, iodine is absorbed and processed by thyroid cells. Using iodine, the cells produce hormones that help the body function normally throughout the day.

During radiodotherapy, radioactive iodine is injected into the patient’s body, which accumulates in the thyroid cells. The tumor cells are destroyed without significant damage to the surrounding tissues. Radioactive iodine is injected intravenously or as a capsule that the patient swallows.

Radioiodine therapy helps avoid future cancer recurrence because the radiation destroys residual tumor cells that were not removed during surgery. This technique is effective if the cancer has spread beyond the primary focus to lymph nodes and tissues.

External radiation therapy

Medullary and anaplastic forms of thyroid cancer do not absorb iodine. In this situation, radiotherapy will be powerless, and therefore contraindicated for patients. For these forms of thyroid tumor, as well as in cases of metastasis to distant organs, patients are offered radiation therapy.

External beam radiation therapy uses high-energy beams (or particles) to destroy cancer cells or slow their growth. A carefully focused beam of radiation is delivered from a machine that is outside the patient’s body.
External radiation therapy is usually given 5 days a week for several weeks.

Chemotherapy

Chemotherapy is rarely used in thyroid cancer therapy. It is indicated in cases of anaplastic thyroid cancer in combination with radiation therapy, and in metastatic tumors that do not respond to standard therapy protocols.

Drugs used in the treatment of thyroid cancer include:

• Dacarbazine,
• Vincristine,
• Cyclophosphamide,
• Doxorubicin,
• Streptozocin,
• Fluorouracil,
• Paclitaxel,
• Docetaxel,
• Carboplatin.

Targeted therapy.

Modern cancer therapy uses new drugs that act directly on the life cycle and growth of tumor cells. These drugs are known as targeted drugs because they have a specific target that they affect.

The following groups of drugs are used in the treatment of thyroid cancer:

• Multikinase inhibitors – Lenvatinib (Lenvatinib) and Sorafenib (Nexavar).
• RET-protein inhibitors – Selpercatinib (Retevmo)
• NTRK gene inhibitors – Larotrectinib (Vitrakvi) and Entrectinib (Rozlytrek)

Targeted medications are prescribed to patients when surgery and radiotherapy have not been effective or are not expected to be of significant benefit in the future. This situation can occur with anaplastic and metastatic cancer.