Thyroid tumours (malignant)

Thyroid carcinoma is rare, having an annual incidence of about 3-5 per 100,000.

• thyroid cancer accounts for about 0.4% of all cancer deaths
• most often diagnosed in people from their 20s through to their 60s (3)
• has been an increase of over 150% in the incidence of thyroid cancer in the UK over the past 30 years (3)
• women are affected more commonly than men in a ratio of 2-3:1
  • most likely to develop in women of reproductive age
• usually presents as a solitary nodule in a patient with normal thyroid hormone levels; cancer is found in about 10% of such cases
  • other symptoms are uncommon, but include cervical lymphadenopathy, hoarseness, difficulty in breathing or swallowing, and discomfort in the neck
    
    
• different types of thyroid cancer:
  • commonest type of thyroid cancer is described as “differentiated”; this accounts for 90% of cases
    • sub-divided into two forms: papillary and follicular adenocarcinoma, which account for 80% and 10% of cases, respectively
    • both develop in cells that produce thyroid hormones, but papillary cancer tends to grow slowly and is usually curable
    • differentiated thyroid cancers are usually treated with surgery, which can be supplemented with radioiodine ablation. Survival rates are excellent
  • five per cent of patients have medullary cancer, which is sometimes familial and can be associated with other endocrine malignancies
    • treatment is with surgery, but this disease is more difficult to control because it tends to be more invasive and cannot be treated with radioiodine
  • there are two rare types which occur in the elderly
    • about 1% of patients have lymphoma of the thyroid, which presents as a rapidly expanding mass and is usually diagnosed on the basis of the patient’s history, together with a tissue diagnosis
      • many of these patients can be cured
    • 3% of patients who have anaplastic thyroid cancer, which presents in a similar way and must be differentiated from lymphoma with a biopsy
      • prognosis is poor
        
        
• are around 3,900 new thyroid cancer cases in the UK every year, that's 11 every day (2016-2018)
• is the 20th most common cancer in the UK, accounting for 1% of all new cancer cases (2016-2018)
• in females in the UK, thyroid cancer is the 17th most common cancer, with around 2,800 new cases every year (2016-2018)
• in males in the UK, thyroid cancer is the 20th most common cancer, with around 1,100 new cases every year (2016-2018)
• incidence rates for thyroid cancer in the UK are highest in people aged 65 to 69 (2016-2018)
• thyroid cancer incidence rates in England in females are similar in the most deprived quintile compared with the least, and in males are similar in the most deprived quintile compared with the least (2013-2017).
• incidence rates for thyroid cancer are higher in the Asian and Black ethnic groups, but lower in people of mixed or multiple ethnicity, compared with the White ethnic group, in England (2013-2017)
• an estimated 22,900 people who had previously been diagnosed with thyroid cancer were alive in the UK at the end of 2010

Almost all thyroid cancers (about 97%) are differentiated and have a good prognosis (3)

Thyroid cancer is usually treated by partial (hemi-) or total thyroidectomy, sometimes followed by radioactive iodine (3)

Once thyroid cancer has been treated, there is still a chance it might recur (3)

• recurrence is uncommon in well-differentiated cancers, but it can be more serious than the original occurrence

Reference:

1. NICE (November 2004). Improving outcomes in head and neck cancers - The Manual
2. CRUK. Thyroid Cancer Statistics (Accessed 21/12/22)
3. NICE (December 2022). Thyroid cancer: assessment and management