Most Frequent Thyroid Cancer in Females
Papillary thyroid cancer is the most frequent type of thyroid cancer in females, accounting for approximately 80% of all thyroid cancer cases.
Epidemiology and Incidence
According to the ESMO Clinical Practice Guidelines, papillary thyroid cancer has an incidence of 8.8 per 100,000 woman-years compared to only 1.06 per 100,000 woman-years for follicular thyroid cancer 1. The incidence rates for papillary thyroid cancer are significantly higher among women than men, with women having a rate that is more than three times higher than men (8.8 vs 2.7 per 100,000 person-years) 1.
The NCCN Guidelines further support this, indicating that of all thyroid carcinoma cases:
- 80% are papillary carcinoma
- 11% are follicular carcinoma
- 3% are Hürthle cell carcinoma
- 4% are medullary carcinoma
- 2% are anaplastic thyroid carcinoma 1
More recent data from 2015 shows that among patients diagnosed with thyroid carcinoma between 2008 and 2012, the distribution was:
- 89% papillary carcinoma
- 5.1% follicular carcinoma
- 2.2% Hürthle cell carcinoma
- 1.7% medullary carcinoma
- 0.8% anaplastic thyroid carcinoma 1
Gender Differences and Risk Factors
Thyroid cancer occurs 2 to 3 times more often in women than in men 1. It is currently the fourth most common malignancy diagnosed in women 1. The peak incidence of thyroid cancer in women is around 45-49 years of age, compared to 65-69 years in men 1.
Among women, papillary thyroid cancer incidence rates vary by ethnicity:
- Higher among Asians (10.96 per 100,000 woman-years)
- Lower among blacks (4.9 per 100,000 woman-years) 1
Prognosis
Papillary thyroid cancer generally has an excellent prognosis:
This is significantly better than the prognosis for anaplastic thyroid carcinoma, which has a 5-year relative survival rate of only about 7% 1.
Clinical Implications
The high prevalence of papillary thyroid cancer in females has important implications for screening and early detection. The increasing incidence of thyroid cancer over recent decades is primarily due to increased detection of small papillary carcinomas through improved diagnostic techniques such as neck ultrasound and fine needle aspiration cytology 1.
Nearly 60-80% of thyroid carcinomas detected nowadays are micropapillary thyroid carcinomas (<1 cm in size), which carry an excellent long-term prognosis 1.
Understanding that papillary thyroid cancer is the most common type in females helps guide appropriate diagnostic and treatment approaches, including surgical management, radioactive iodine therapy, and TSH suppression with thyroid hormone replacement.