Thyroid Cancer
Disease Details
Family Health Simplified
- Description
- Thyroid cancer is a disease in which malignant cells form in the tissues of the thyroid gland, potentially leading to symptoms like a neck lump or changes in voice.
- Type
-
Thyroid cancer primarily includes several types, such as papillary, follicular, medullary, and anaplastic thyroid cancer. The type of genetic transmission can vary:
1. **Papillary and Follicular Thyroid Cancer**: These types are usually not inherited and are often sporadic. However, certain genetic mutations, such as in the BRAF gene, may contribute to their development.
2. **Medullary Thyroid Cancer (MTC)**: This type can be sporadic or familial. The familial form is associated with multiple endocrine neoplasia type 2 (MEN2) and is inherited in an autosomal dominant pattern due to mutations in the RET proto-oncogene.
3. **Anaplastic Thyroid Cancer**: Similar to papillary and follicular types, this is typically not inherited and arises from pre-existing thyroid cancers. Genetic mutations such as TP53 may play a role.
Overall, the specific genetic transmission varies depending on the type of thyroid cancer, with medullary thyroid cancer being the most commonly associated with a hereditary pattern. - Signs And Symptoms
- Most often, the first symptom of thyroid cancer is a nodule in the thyroid region of the neck. However, up to 65% of adults have small nodules in their thyroids, but typically under 10% of these nodules are found to be cancerous. Sometimes, the first sign is an enlarged lymph node. Later symptoms that can be present are pain in the anterior region of the neck and changes in voice due to an involvement of the recurrent laryngeal nerve.Thyroid cancer is usually found in a euthyroid patient, but symptoms of hyperthyroidism or hypothyroidism may be associated with a large or metastatic, well-differentiated tumor. Thyroid nodules are of particular concern when they are found in those under the age of 20. The presentation of benign nodules at this age is less likely, thus the potential for malignancy is far greater.
- Prognosis
-
The prognosis of thyroid cancer is related to the type of cancer and the stage at the time of diagnosis. For the most common form of thyroid cancer, papillary, the overall prognosis is excellent. Indeed, the increased incidence of papillary thyroid carcinoma in recent years is likely related to increased and earlier diagnosis. One can look at the trend to earlier diagnosis in two ways. The first is that many of these cancers are small and not likely to develop into aggressive malignancies. A second perspective is that earlier diagnosis removes these cancers at a time when they are not likely to have spread beyond the thyroid gland, thereby improving the long-term outcome for the patient. No consensus exists at present on whether this trend toward earlier diagnosis is beneficial or unnecessary.
The argument against early diagnosis and treatment is based on the logic that many small thyroid cancers (mostly papillary) will not grow or metastasize. This view holds the overwhelming majority of thyroid cancers are overdiagnosed that is, will never cause any symptoms, illness, or death for the patient, even if nothing is ever done about the cancer. Including these overdiagnosed cases skews the statistics by lumping clinically significant cases in with apparently harmless cancers. Thyroid cancer is incredibly common, with autopsy studies of people dying from other causes showing that more than one-third of older adults technically have thyroid cancer, which is causing them no harm. Detecting nodules that might be cancerous is easy, simply by feeling the throat, which contributes to the level of overdiagnosis. Benign (noncancerous) nodules frequently co-exist with thyroid cancer; sometimes, a benign nodule is discovered, but surgery uncovers an incidental small thyroid cancer. Increasingly, small thyroid nodules are discovered as incidental findings on imaging (CT scan, MRI, ultrasound) performed for another purpose; very few of these people with accidentally discovered, symptom-free thyroid cancers will ever have any symptoms, and treatment in such patients has the potential to cause harm to them, not to help them.Thyroid cancer is three times more common in women than in men, but according to European statistics, the overall relative 5-year survival rate for thyroid cancer is 85% for females and 74% for males.The table below highlights some of the challenges with decision making and prognostication in thyroid cancer. While general agreement exists that stage I or II papillary, follicular, or medullary cancer have good prognoses, when evaluating a small thyroid cancer to determine which ones will grow and metastasize and which will not is not possible. As a result, once a diagnosis of thyroid cancer has been established (most commonly by a fine needle aspiration), a total thyroidectomy likely will be performed.
This drive to earlier diagnosis has also manifested itself on the European continent by the use of serum calcitonin measurements in patients with goiter to identify patients with early abnormalities of the parafollicular or calcitonin-producing cells within the thyroid gland. As multiple studies have demonstrated, the finding of an elevated serum calcitonin is associated with the finding of a medullary thyroid carcinoma in as high as 20% of cases.
In Europe where the threshold for thyroid surgery is lower than in the United States, an elaborate strategy that incorporates serum calcitonin measurements and stimulatory tests for calcitonin has been incorporated into the decision to perform a thyroidectomy; thyroid experts in the United States, looking at the same data, have for the most part not incorporated calcitonin testing as a routine part of their evaluations, thereby eliminating a large number of thyroidectomies and the consequent morbidity. The European thyroid community has focused on prevention of metastasis from small medullary thyroid carcinomas; the North American thyroid community has focused more on prevention of complications associated with thyroidectomy (see American Thyroid Association guidelines below).
As demonstrated in the table below, individuals with stage III and IV disease have a significant risk of dying from thyroid cancer. While many present with widely metastatic disease, an equal number evolve over years and decades from stage I or II disease. Physicians who manage thyroid cancer of any stage recognize that a small percentage of patients with low-risk thyroid cancer will progress to metastatic disease.
Improvements have been made in thyroid cancer treatment during recent years. The identification of some of the molecular or DNA abnormalities has led to the development of therapies that target these molecular defects. The first of these agents to negotiate the approval process is vandetanib, a tyrosine kinase inhibitor that targets the RET proto-oncogene, two subtypes of the vascular endothelial growth factor receptor, and the epidermal growth factor receptor. More of these compounds are under investigation and are likely to make it through the approval process. For differentiated thyroid carcinoma, strategies are evolving to use selected types of targeted therapy to increase radioactive iodine uptake in papillary thyroid carcinomas that have lost the ability to concentrate iodide. This strategy would make possible the use of radioactive iodine therapy to treat "resistant" thyroid cancers. Other targeted therapies are being evaluated, making life extension possible over the next 5–10 years for those with stage III and IV thyroid cancer.
Prognosis is better in younger people than older ones.Prognosis depends mainly on the type of cancer and cancer stage. - Onset
- Thyroid cancer onset can be influenced by several risk factors, including genetic predisposition, exposure to radiation, and certain inherited conditions. It can occur at any age but is more commonly diagnosed in individuals between 30 and 60 years old. The onset often involves the development of a lump in the neck, changes in voice, difficulty swallowing, or swollen lymph nodes. Early stages may be asymptomatic.
- Prevalence
- The prevalence of thyroid cancer varies by region and population, but it generally accounts for about 3-5% of all cancers. It is more common in women than men. The incidence has been increasing, largely due to improved detection methods.
- Epidemiology
- Thyroid cancer, in 2010, resulted in 36,000 deaths globally up from 24,000 in 1990.Obesity may be associated with a higher incidence of thyroid cancer, but this relationship remains the subject of much debate.Thyroid cancer accounts for less than 1% of cancer cases and deaths in the UK. Around 2,700 people were diagnosed with thyroid cancer in the UK in 2011, and around 370 people died from the disease in 2012.However, in South Korea, thyroid cancer was the 5th most prevalent cancer, which accounted for 7.7% of new cancer cases in 2020.
- Intractability
- Thyroid cancer is not generally considered intractable. Many cases of thyroid cancer, particularly papillary and follicular types, respond well to treatments such as surgery, radioactive iodine therapy, and thyroid hormone therapy. Prognosis is often favorable, especially when diagnosed early. However, more aggressive types like anaplastic thyroid cancer can be more challenging to treat.
- Disease Severity
- Thyroid cancer is a type of cancer that occurs in the thyroid gland. Disease severity can vary based on factors such as the type of thyroid cancer (e.g., papillary, follicular, medullary, anaplastic), the stage at diagnosis, and the patient's overall health. Most cases of thyroid cancer, particularly the papillary and follicular types, tend to be highly treatable with a good prognosis if detected early. However, more aggressive forms like anaplastic thyroid cancer have a poorer prognosis.
- Healthcare Professionals
- Disease Ontology ID - DOID:1781
- Pathophysiology
-
Thyroid cancer is characterized by the uncontrolled growth of cells within the thyroid gland, a butterfly-shaped organ located at the base of the neck. The pathophysiology involves genetic mutations that lead to the formation of malignant tumors. These mutations can activate oncogenes, which promote cell growth and proliferation, or inactivate tumor suppressor genes, which usually help control cell division and prevent cancer.
Papillary thyroid carcinoma (PTC) is the most common type, often associated with mutations in the BRAF gene or rearrangements in the RET/PTC genes. Follicular thyroid carcinoma (FTC) may involve RAS mutations or PAX8-PPARγ rearrangements. Medullary thyroid carcinoma (MTC) typically features mutations in the RET proto-oncogene.
These genetic alterations disrupt normal thyroid cell functions, such as hormone production and regulation, leading to tumor development. The precise molecular mechanisms often vary among different thyroid cancer types, which can influence prognosis and treatment options. - Carrier Status
- Thyroid cancer typically does not have a carrier status like some hereditary diseases. However, certain genetic mutations and hereditary conditions can increase the risk of developing thyroid cancer. For example, familial medullary thyroid carcinoma (FMTC) is associated with mutations in the RET proto-oncogene. Genetic screening may be recommended for individuals with a family history of such conditions to assess their risk.
- Mechanism
-
Thyroid cancer develops when cells in the thyroid gland undergo genetic mutations that lead to uncontrolled growth and tumor formation. The molecular mechanisms involved in thyroid cancer include:
1. **Genetic Alterations**:
- **BRAF Mutations**: Most commonly, the BRAF V600E mutation is seen in papillary thyroid cancers (PTC) leading to constitutive activation of the MAPK/ERK signaling pathway, promoting cell proliferation and survival.
- **RET/PTC Rearrangements**: These genetic rearrangements result in the activation of the RET proto-oncogene, which also activates the MAPK/ERK pathway.
- **RAS Mutations**: Mutations in RAS genes (HRAS, KRAS, NRAS) activate both the MAPK/ERK and PI3K/AKT pathways, found in follicular thyroid cancer (FTC) and a subset of PTC.
2. **Tumor Suppressor Genes**:
- **p53 Mutations**: Common in anaplastic thyroid cancer (ATC), leading to loss of cell cycle control and apoptosis.
- **PTEN Mutations**: Inactivation of PTEN, a tumor suppressor that negatively regulates the PI3K/AKT pathway, is implicated in FTC and ATC.
3. **Other Molecular Pathways**:
- **PI3K/AKT Pathway**: Activation through mutations in PI3K or loss of PTEN function promotes cell growth and survival, commonly seen in more aggressive types like FTC and ATC.
- **TERT Promoter Mutations**: Mutations in the promoter region of the telomerase reverse transcriptase (TERT) gene lead to increased telomerase activity, contributing to the immortalization of cancer cells, often seen in aggressive and advanced thyroid cancers.
The interplay between these molecular mechanisms results in thyroid cell transformation, increased proliferation, inhibited apoptosis, and ultimately the development of thyroid cancer. - Treatment
-
Thyroidectomy and dissection of central neck compartment is the initial step in treatment of thyroid cancer in the majority of cases. Thyroid-preserving operations may be applied in cases, when thyroid cancer exhibits low biological aggressiveness (e.g. well-differentiated cancer, no evidence of lymph-node metastases, low MIB-1 index, no major genetic alterations like BRAF mutations, RET/PTC rearrangements, p53 mutations etc.) in patients younger than 45 years.
If the diagnosis of well-differentiated thyroid cancer (e.g. papillary thyroid cancer) is established or suspected by FNA, then surgery is indicated, whereas watchful waiting strategy is not recommended in any evidence-based guidelines.Watchful waiting reduces overdiagnosis and overtreatment of thyroid cancer among old patients.Radioactive iodine-131 is used in people with papillary or follicular thyroid cancer for ablation of residual thyroid tissue after surgery and for the treatment of thyroid cancer. Patients with medullary, anaplastic, and most Hurthle-cell cancers do not benefit from this therapy.External irradiation may be used when the cancer is unresectable, when it recurs after resection, or to relieve pain from bone metastasis.Sorafenib and lenvatinib are approved for advanced metastatic thyroid cancer. Numerous agents are in phase II and III clinical trials.Post surgical monitoring for recurrence or metastasis may include routine ultrasound, CT scans, FDG-PET/CT, radioactive iodine whole body scans, and routine laboratory blood tests for changes in thyrogolubin, thyroglobuilin antibodies, or calcitonin, depending on the variant of thyroid cancer. - Compassionate Use Treatment
-
Compassionate use treatment for thyroid cancer refers to the use of investigational drugs or treatments outside of clinical trials for patients with no other treatment options. These are typically administered when standard treatments have failed, or there are no available alternatives.
Off-label treatments involve the use of FDA-approved medications in a manner not specified in the FDA's approved packaging label. This might include different dosages, formulations, or using the drug to treat a condition other than what it was approved for. For thyroid cancer, off-label cancer drugs might be used depending on the clinical scenario and physician discretion.
Experimental treatments for thyroid cancer commonly include participation in clinical trials testing new therapies. These trials might explore new drugs, combination therapies, or innovative approaches like immunotherapy, targeted therapy, and advanced radiation techniques. Participation in such trials often requires specific patient eligibility criteria.
Patients seeking compassionate use, off-label, or experimental treatments should consult their healthcare provider to discuss potential risks and benefits, as well as eligibility requirements. - Lifestyle Recommendations
-
### Lifestyle Recommendations for Thyroid Cancer
1. **Healthy Diet:**
- Focus on a balanced diet rich in fruits, vegetables, lean proteins, and whole grains.
- Maintain an adequate intake of essential nutrients, particularly iodine, which is crucial for thyroid health.
2. **Regular Exercise:**
- Engage in regular physical activity to help maintain overall health and well-being.
- Aim for at least 150 minutes of moderate-intensity exercise per week.
3. **Avoid Tobacco and Limit Alcohol:**
- Refrain from smoking, as it can exacerbate health problems.
- Limit alcohol consumption to maintain optimal health.
4. **Stress Management:**
- Practice stress-reducing techniques like meditation, yoga, or deep-breathing exercises.
- Ensure adequate rest and prioritize sleep.
5. **Regular Medical Check-ups:**
- Keep up with scheduled medical appointments and follow your doctor’s recommendations.
- Monitor thyroid function and follow-up on any concerns with your healthcare provider.
6. **Medication Adherence:**
- Take prescribed medications as directed, including those for thyroid hormone replacement if needed.
7. **Radiation Precautions:**
- If exposed to radiation therapy, follow safety guidelines provided by your healthcare provider.
Adopting these lifestyle recommendations can support overall health and complement medical treatment for thyroid cancer. - Medication
-
In the management of thyroid cancer, medication may be used depending on the specific type and stage of the cancer. Common medications include:
1. **Levothyroxine**: Often prescribed to replace thyroid hormone after the thyroid gland is removed. It also helps to suppress the release of Thyroid Stimulating Hormone (TSH), which is important because high TSH levels can stimulate the growth of any remaining cancer cells.
2. **Radioactive Iodine (RAI) Therapy**: Used particularly in cases of differentiated thyroid cancers such as papillary and follicular thyroid cancer. It helps to destroy any remaining thyroid tissue post-surgery and can be helpful in targeting residual cancer cells.
3. **Targeted Therapies**: For advanced or refractory thyroid cancers, targeted therapies that inhibit specific pathways or mutations within the cancer cells might be used. Examples include:
- **Sorafenib**: A kinase inhibitor used for advanced thyroid cancer.
- **Lenvatinib**: Another kinase inhibitor used for progressive, radioactive iodine-refractory thyroid cancer.
4. **Chemotherapy**: Traditional chemotherapy is not commonly used for thyroid cancer but may be considered in aggressive or advanced cases that do not respond well to other treatments.
5. **Multikinase Inhibitors**: Used in progressive cases where RAI therapy is not effective. Examples include vandetanib and cabozantinib.
Management often includes a combination of these medications alongside other treatments such as surgery and radiation therapy, tailored to the individual patient's condition. - Repurposable Drugs
-
For thyroid cancer, some repurposable drugs that have shown potential include:
1. **Metformin** - Originally used for Type 2 diabetes, it has been noted for its anticancer properties.
2. **Sorafenib** - Initially developed for liver and kidney cancers, it is also used to treat advanced thyroid cancer.
3. **Lenvatinib** - Originally for renal cancer, it has been repurposed for differentiated thyroid cancer.
These drugs may be considered based on individual patient conditions and specific medical advice. - Metabolites
-
In the context of thyroid cancer, several metabolites have been studied for their potential roles in diagnosis, prognosis, and treatment. Some key metabolites include:
1. **Choline** - Elevated levels may indicate malignancy due to increased membrane synthesis.
2. **Lactate** - Elevated in cancer cells due to anaerobic glycolysis.
3. **Glutamine** - High demand in cancer cells for nucleotide and amino acid synthesis.
"NAN" seems to not correspond to a recognized metabolite related to thyroid cancer. It might be a typo or require further clarification. - Nutraceuticals
-
For thyroid cancer, there's no strong evidence that nutraceuticals—foods or food products that provide health and medical benefits—can effectively treat the disease. Patients should focus on standard treatments like surgery, radioactive iodine therapy, and thyroid hormone therapy.
Regarding nanotechnology (nan), research is ongoing into using nanoparticles for targeted drug delivery and imaging in thyroid cancer. These approaches aim to improve treatment efficacy and minimize side effects by specifically targeting cancer cells. However, these technologies are still largely experimental and not yet part of standard clinical practice. - Peptides
-
Thyroid cancer is a type of cancer that affects the thyroid gland. Peptides, which are short chains of amino acids, can play a role in diagnosing and treating thyroid cancer. Some peptides are used in imaging and diagnostic procedures, such as radio-labeled peptides that bind to thyroid cancer cells, enhancing the visibility of tumors during scans. Additionally, peptide-based therapies are being explored for targeted treatment, aiming to improve the delivery of anti-cancer drugs directly to cancer cells, thereby minimizing side effects.
Nanotechnology is also emerging as a promising field in thyroid cancer care. Nanoparticles can be designed to deliver drugs directly to the tumor site, improving the efficacy while reducing systemic toxicity. Nanotechnology is also used in diagnostic applications, such as creating more sensitive imaging techniques to detect thyroid cancer at earlier stages. Research is ongoing to further develop and optimize these approaches for better patient outcomes.