Thyroid cancer

Thyroid cancer is the most common endocrine malignancy worldwide, with rising incidence rates. This increase is attributed not only to improved awareness and diagnostic sensitivity but also to environmental factors and broader global changes that may contribute to disease occurrence.

What are the main subtypes of thyroid cancer?

Thyroid cancer is typically classified into four main subtypes:

• Papillary thyroid cancer (PTC), the most common type, accounting for ~90% of all cases. It is highly treatable with a good prognosis
• Follicular thyroid cancer (FTC), the second most common type (~20% of cases). Most cases are mild and respond well to treatment, though ~20% may be more aggressive
• Medullary thyroid cancer (MTC), a rare subtype (1–5% of cases) with a poorer prognosis
• Anaplastic thyroid cancer, an extremely rare (~2% of cases) but highly aggressive subtype, responsible for approximately 50% of thyroid cancer–related deaths

What are the risk factors for thyroid cancer?

Risk factors for thyroid cancer include both modifiable and unmodifiable elements:

• Modifiable: Obesity, smoking, heavy alcohol consumption, physical inactivity, and exposure to radiation or environmental pollutants (e.g., heavy metals, endocrine-disruptors)
• Unmodifiable: Female sex, genetic predisposition (e.g., RET, BRAF, RAS mutations), and preexisting benign thyroid conditions, including hyperthyroidism and goiter

What are the symptoms of thyroid cancer?

Symptoms of thyroid cancer include hoarseness, numbness, and a visible lump in the neck. Sleep disturbances, fatigue, and emotional distress are common, with over 30% of patients reporting anxiety and depression.

How is thyroid cancer diagnosed?

Approximately half of thyroid cancer cases are discovered incidentally during imaging for unrelated conditions. Diagnosis typically involves physical examination, ultrasound, and fine-needle aspiration biopsy. Molecular testing and advanced imaging techniques like PET/MRI help determine tumor type and extent.

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References

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