Medullary thyroid carcinoma (MTC) is a rare but aggressive type of thyroid cancer that originates from parafollicular cells (C cells), which produce calcitonin. This tumor differs from more common forms of thyroid cancer, such as papillary and follicular carcinomas. MTC is often associated with multiple endocrine neoplasia (MEN), especially MEN 2A and 2B. Patients with medullary thyroid carcinoma may present with a variety of clinical symptoms, including thyroid enlargement, neck pain, regional lymph node metastasis, and elevated blood levels of calcitonin, which may be an important marker for diagnosis and monitoring of this disease.
History of the disease and interesting historical facts
The history of medullary thyroid carcinoma dates back to the mid-20th century, when this disease was first described as a separate nosological entity. The main studies devoted to MTC were conducted in the 1960s, when scientists began to understand its connection with multiple endocrine neoplasia syndromes. It was established that the hereditary factor plays an important role in the development of MTC, and in 1980 the RET gene was described as one of the most significant in this context. Improvements in molecular technologies allow for a deeper study of genetic predisposition and mechanisms of tumor aggression.
Epidemiology
Medullary thyroid carcinoma is relatively rare, accounting for 3% to 10% of all thyroid cancer cases. According to statistics, on average, about 1-2 cases per 100,000 people per year are registered worldwide. The incidence of the disease may vary depending on the region and genetic factors, reaching higher rates among certain population groups. MTC is most often diagnosed in people aged 30 to 60 years, however, cases are possible in both children and the elderly. There are variants of development of both sporadic (sporadic) form and hereditary, associated with genetic mutations.
Genetic predisposition to this disease
Genetic studies have demonstrated that mutations in the RET gene are leading factors contributing to the development of medullary thyroid carcinoma, especially in the context of the hereditary form of the disease. In particular, RET mutations lead to the activation of oncogenic signaling, which contributes to tumor progression. Different variants of mutations in this gene can lead to different phenotypic manifestations. There is also a link between MTC and other genes, such as MEN1 and RAS, which opens up new horizons in understanding the etiology of this disease.
Risk factors for the development of this disease
Risk factors for medullary thyroid carcinoma include:
- Heredity and genetic predisposition, especially if there is a family history of the disease.
- Exposure to radiation, including radiotherapy to the neck area.
- Environmental factors such as high levels of iodine in medications.
- Certain chronic thyroid conditions may increase your risk, including thyroiditis.
It is known that regular medical examination can help in early detection of the disease in people at high risk.
Diagnosis of this disease
Diagnosis of medullary thyroid carcinoma begins with a clinical examination of the patient. The main symptoms may include:
- Enlargement of the thyroid gland (goiter).
- Neck pain or discomfort.
- Metastases to the lymph nodes and other organs in the late stages of the disease.
Laboratory tests include:
- Calcitonin measurement: elevated levels may indicate the presence of MTC.
- Genetic testing for mutations in the RET gene.
Radiological examinations such as thyroid ultrasound help visualize the tumor and assess for metastases. CT and MRI can be used to assess the extent of the disease in more detail. Differential diagnosis includes exclusion of papillary and follicular carcinomas, as well as other thyroid diseases.
Treatment
Treatment of medullary thyroid carcinoma includes a combination of surgery and adjuvant therapy. Surgery is the primary method and largely determines the outcome of the disease:
- Thyroidectomy (removal of the thyroid gland) is the standard treatment.
- Removal of regional lymph nodes is recommended in case of damage.
Pharmacological treatment includes the use of incretins, which are aimed at reducing calcitonin levels and preventing recurrence. Drugs to treat comorbidities may also be used. Other methods, such as radiotherapy, may be used as part of palliative care or to reduce symptoms in patients with metastatic disease.
List of medications used to treat this disease
- Sindate (Sinoket) – affects the level of calcitonin.
- Selpercattinib is a new drug for the treatment of metastatic MTC with RET mutations.
- Ponatinib is a drug for the treatment of cancers with RAS mutations.
Disease monitoring
After completion of treatment, regular monitoring of the patient's condition is important, which includes:
- Regular tests for calcitonin levels.
- Laboratory tests to detect relapse of the disease.
- Ultrasound and other imaging tests to assess the thyroid gland and lymph nodes.
The prognosis for patients with medullary carcinoma depends on the stage of the disease, the patient's age, and the presence of metastases at the time of diagnosis. If detected early, the prognosis can be relatively positive, but the disease often has a tendency to relapse.
Age-related features of the disease
MTC can manifest itself at any age, but is most often diagnosed in adults aged 40 to 60 years. The disease is also possible in children, but usually manifests itself in the form of hereditary forms associated with multiple endocrine neoplasia syndromes. The process and course of the disease can vary: older patients have more pronounced metastases and an aggressive course, while younger patients may have a more favorable prognosis with early diagnosis and adequate treatment.
Questions and Answers
- What is medullary thyroid carcinoma? It is a rare type of thyroid cancer that arises from the calcitonin-producing parafollicular cells and is often associated with hereditary forms of the disease.
- What are the symptoms of medullary thyroid carcinoma? The main symptoms are an enlarged thyroid gland, pain in the neck and enlarged regional lymph nodes.
- What risk factors contribute to the development of this type of cancer? The main risk factors include genetic predisposition, radiation exposure, and the presence of other thyroid diseases.
- What is the role of genetic testing in the diagnosis of medullary carcinoma? Genetic testing can identify mutations in the RET gene, which can help establish a diagnosis, especially in patients with inherited forms of the disease.
- What is the treatment for medullary thyroid carcinoma? Treatment includes surgical removal of the thyroid gland, as well as adjuvant therapy and calcitonin levels to monitor the patient's condition.
