Epidemiology of Thyroid Nodules and Thyroid Cancer

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  • Palpable thyroid nodules:
    • Occur in 5% of women and 1% of men in iodine-sufficient areas
  • Thyroid nodule prevalence varies with detection mode and increases with age:
    • 2% to 6% prevalence by palpation
    • 19% to 68% prevalence by ultrasound
  • Among all thyroid nodules:
    • 7% to 15% are malignant:
      • The proportion varies with:
        • Age
        • Gender
        • Radiation exposure
        • Family history
        • Other factors
  • At least 94% of thyroid carcinomas are:
    • Differentiated thyroid cancer (DTC):
      • Primarily papillary thyroid carcinoma (PTC), and follicular thyroid carcinoma
  • The annual incidence of thyroid cancer per 100 000 person has increased from:
    • 4.6 in 1974 to 1977 to 14.4 in 2010-2013
  • In the United States in 2020:
    • 52,890 new cases of thyroid cancer are estimated to be diagnosed (2.9% of all new cancer cases):
      • This figure is largely attributable to:
        • Incidentally detected subclinical disease
    • Approximately 2,180 deaths from thyroid cancer are estimated (0.4% of all cancer deaths)
  • Rate of New Cases and Deaths per 100,000: 
    • The rate of new cases of thyroid cancer was 15.7 per 100,000 men and women per year
    • The death rate was 0.5 per 100,000 men and women per year:
      • These rates are age-adjusted and based on 2013 to 2017 cases and deaths
  • Lifetime Risk of Developing Cancer:
    • Approximately 1.3% of men and women will be diagnosed with thyroid cancer at some point during their lifetime, based on 2015 to 2017 data
  • Prevalence of This Cancer:
    • In 2017, there were an estimated 859,838 people living with thyroid cancer in the United States.

How Many People Survive 5 Years Or More after Being Diagnosed with Thyroid Cancer?

  • Relative survival statistics compare the survival of patients diagnosed with cancer with the survival of people in the general population who are the same age, race, and sex and who have not been diagnosed with cancer:
    • Because survival statistics are based on large groups of people, they cannot be used to predict exactly what will happen to an individual patient
    • No two patients are entirely alike, and treatment and responses to treatment can vary greatly

Survival by Stage

  • Cancer stage at diagnosis:
    • Which refers to extent of a cancer in the body:
      • Determines treatment options and has a strong influence on the length of survival
  • In general, if the cancer is found only in the part of the body where it started:
    • It is localized (sometimes referred to as stage 1)
  • If it has spread to a different part of the body;\
    • The stage is regional or distant
  • The earlier thyroid cancer is caught:
    • The better chance a person has of surviving five years after being diagnosed
  • For thyroid cancer:
    • 66.5% are diagnosed at the local stage:
      • The 5-year relative survival for localized thyroid cancer is 99.9%