Co-occurrence of second primary malignancy in patients with thyroid cancer

QJM. 2014 Aug;107(8):643-8. doi: 10.1093/qjmed/hcu051. Epub 2014 Mar 11.


Background: The discovery of asynchronous or synchronous double or multiple malignancies in patients is not uncommon. The co-occurrence of second primary malignancy (SPM) could be randomly occurring or association with risk factors such as environmental, genetic predisposition and therapy-related.

Materials and methods: We retrieved ∼782 million claim records consisting of 10.8 million males and 10.6 million females from Taiwan's National Health Insurance, which were collected for a period of 3 years (January 2000-December 2002). All the patient records were stratified by gender and ages at a 20-year interval with SPMs and specific groups. Interestingness or Q-value was used to measure strength of the disease-disease associations.

Results: A total of 9423 thyroid cancer (female: 7483, male: 1940), 276 184 SPM (female: 141 023, male: 135 161) and 861 co-occurrence cases (female: 583, male: 278) were recorded. The co-occurrence incidence rate of head and neck, breast, digestive system and lung was 1.93%, 1.59%, 1.44% and 1.18%, respectively. Malignancy of salivary glands, laryngx, sarcoma, lymphoid tissue, mouth, central nervous system and lungs found Q-value >10. Malignancies with intermediate Q-values (5.0-9.9) were observed in nasopharynx, kidney and ureter, breast, stomach and skin. Prostate, leukemia, urinary bladder, ovary, colon, liver and uterine cervix cancer have lower Q-values (1.0-4.9).

Conclusion: Co-occurrence ratio of thyroid cancer and SPM was high, occurred in all organ systems. We postulated that the aggressive use of modern diagnostic modalities, aggressive radioiodine treatment, pre-existing molecular oncogen mutations, and thyroid hormone for simultaneously supple-mentary and suppressive therapies were responsible.

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aged
  • Aged, 80 and over
  • Databases, Factual
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasms, Second Primary / epidemiology*
  • Retrospective Studies
  • Sex Distribution
  • Taiwan / epidemiology
  • Thyroid Neoplasms / epidemiology*
  • Young Adult