About Medullary Thyroid Cancer

Overview

Medullary thyroid cancer (MTC) is a form of cancer that starts in the thyroid gland, located at the front of the neck below the Adam's apple. This gland produces hormones that regulate various body functions. MTC originates specifically in the thyroid’s inner section, known as the medulla, where special cells called parafollicular C cells are located. Normally, these C cells release hormones, but in MTC, they become cancerous and grow uncontrollably. MTC can either occur randomly or be inherited and accounts for around 35% of all thyroid cancers. It can also spread to other areas, like the liver, lungs, bones, skin, and brain. Early diagnosis and treatment are essential for a better outcome, and regular monitoring of blood markers after surgery helps check the status of the disease.

Causes and Risk Factors

The root causes of MTC are mainly related to genetic mutations.

Non-modifiable risk factors for MTC are factors that cannot be changed. These include:

• Family history: Individuals with a family history of MTC are more likely to develop it.
• Genetic mutations: Certain gene mutations, such as RET proto-oncogene mutations, are associated with an increased risk of MTC.

Modifiable risk factors for MTC are factors that can be influenced or changed. These include:

• Smoking: Smoking has been linked to an increased risk of MTC.
• Radiation exposure: Previous exposure to radiation, especially during childhood, may increase the risk of developing MTC.

It's important to note that while these risk factors may increase the likelihood of developing MTC, they do not guarantee its occurrence. If you have concerns about your risk factors or symptoms, it's best to consult with a healthcare professional for further evaluation and guidance.

Symptoms

Early symptoms of Medullary Thyroid Cancer (MTC) can include:

• Painless lump in the front of the neck
• Neck problems such as pain and stiffness
• Voice changes and hoarseness
• Coughing
• Trouble swallowing

As MTC progresses or reaches higher severity, additional symptoms may occur:

• Dyspnea (shortness of breath) due to tumor growth or metastasis blocking the airways
• Pain from the spread of the disease into nearby areas
• Emotional changes, such as increased stress and anxiety
• Side effects from medications, including lethargy and sleepiness
• Extreme fatigue
• Weight loss, often unexpected and including muscle loss

It's important to note that individuals with MTC may experience symptoms differently, and not all symptoms may be present. If you are experiencing any concerning symptoms, it's best to consult with a healthcare professional for an accurate diagnosis and appropriate management.

Diagnosis

To diagnose Medullary Thyroid Cancer, the following examinations, tests, and procedures are commonly performed:

• Physical exam and health history: The healthcare provider examines the body for signs of disease, such as lumps or swelling in the neck, voice box, and lymph nodes.
• Calcitonin blood test: This test checks for the presence of Medullary Thyroid Cancer by measuring the levels of calcitonin in the blood.
• Laryngoscopy: This procedure involves using a mirror or a flexible tube called a laryngoscope to assess vocal cord function and check for any abnormalities.
• Thyroid biopsy: This procedure involves obtaining a sample of thyroid tissue for examination under a microscope. Genetic testing may also be performed on the cells obtained during the biopsy.
• Thyroid scan: This test uses radioactive iodine to create images of the thyroid gland and detect any abnormalities.
• Blood tests for thyroid function: These tests measure the levels of thyroid hormones in the blood to assess thyroid function.
• Ultrasound of the thyroid and neck lymph nodes: This imaging test uses sound waves to create images of the thyroid gland and nearby lymph nodes.
• CT scan of the neck: This imaging test provides detailed images of the neck to determine the extent of the cancerous mass.
• PET scan: This imaging test uses a radioactive tracer to detect cancer cells in the body.

To determine the stage or severity of Medullary Thyroid Cancer, additional examinations, tests, and procedures may include:

• Blood hormone studies: These tests measure hormone levels released by organs and tissues in the body.
• Blood chemistry studies: These tests measure substances released into the blood by organs and tissues.
• Surgical biopsy: During surgery, a sample of thyroid tissue is removed for examination under a microscope to check for signs of cancer.

It's important to consult your healthcare professional for personalized advice regarding these examinations, tests, and procedures.

Treatment Options

The goals of treatment for Medullary Thyroid Cancer (MTC) are to kill cancer cells, prevent the spread of cancer, and improve the patient's quality of life. Here are the different treatment options and how they work to achieve these goals:

• Targeted Therapy: Medications called tyrosine kinase inhibitors (vandetanib, cabozantinib, selpercatinib, or pralsetinib) are used to target specific proteins involved in cancer growth and survival. These drugs inhibit tumor cell proliferation while minimizing harm to normal cells.
• Surgery: Surgical procedures like total thyroidectomy (removal of the entire thyroid gland) may be performed as palliative therapy to relieve symptoms and improve quality of life for patients with MTC near or in the thyroid.

It's important to note that treatment plans should be discussed with a healthcare professional to determine the most appropriate approach for each individual. Health behavior changes, such as maintaining a healthy lifestyle and following a doctor-prescribed treatment plan, can also support overall treatment goals.

Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.