The increasing incidence of small thyroid cancers: where are the cases coming from?

Laryngoscope. 2010 Dec;120(12):2446-51. doi: 10.1002/lary.21076.


Objectives/hypothesis: To identify the trigger events that lead to the detection of otherwise asymptomatic thyroid cancers.

Study design: Retrospective cohort.

Methods: Chart abstraction of patients who underwent thyroidectomy. Iterative development of a classification algorithm to categorize trigger events.

Results: A total of 279 thyroidectomies were performed, which resulted in 95 new diagnoses of thyroid cancer. Just less than half of identified cancers (44 cancers, 46%) were in the 127 thyroidectomies performed after identification of a thyroid abnormality by either screening or chance. A screening trigger event occurs when a physician performs a routine thyroid examination when there is no specific neck complaint. A chance trigger event can occur either by serendipity (a radiologic test done for a different reason) or by diagnostic cascade (identification of a thyroid abnormality on any test that does not plausibly explain the patient's presenting complaint). Physician screening examination was the trigger event for 49 thyroidectomies (18%). Serendipity was the trigger event for 41 thyroidectomies (15%). Diagnostic cascade was the trigger event for 33 thyroidectomies (12%). Only 75 thyroidectomies (27%) were performed because of symptoms directly referable to a neck mass, such as a patient complaint of feeling something in the neck. Forty percent received a cancer diagnosis (30 of 75 cases).

Conclusions: Screening and chance identification were the trigger events for just less than half of both the cancers diagnosed and the thyroidectomies performed. These extra cancer diagnoses and surgeries are a significant burden for patients. These data will help direct future efforts to curb treatment of clinically unimportant thyroid nodules.

Publication types

  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Mass Screening / standards*
  • Middle Aged
  • New Hampshire / epidemiology
  • Prognosis
  • Quality of Health Care*
  • Retrospective Studies
  • Survival Rate / trends
  • Thyroid Neoplasms / epidemiology*
  • Thyroid Neoplasms / surgery
  • Thyroidectomy
  • Vermont / epidemiology
  • Young Adult