Reproductive factors and thyroid cancer risk: Meta-analysis

Head Neck. 2019 Dec;41(12):4199-4208. doi: 10.1002/hed.25945. Epub 2019 Oct 8.

Abstract

Background: Assessed pooled risk on reproductive factors and oral contraceptives (OC) on thyroid cancer (TC) using published studies (1996-2017).

Methods: Summary odds ratio (OR) for case-control studies (n = 10) and risk ratio (RR) for cohort studies (n = 9) was done.

Results: OR was 1.43 (95% CI: 1.16-1.77) for age at menarche >14 years, 1.49 (95% CI: 1.19-1.86) for parity >2, 1.38 (95% CI: 1.18-1.61) for miscarriage/abortion, and 2.05 (95% CI: 1.39-3.01) for artificial menopause. A protective effect (ORs: 0.85; 95% CI: 0.72-0.99) on TC was observed for prolonged use of OCs. RR was 1.17 (95% CI: 0.90-1.57) for age at menarche >14 years, 1.10 (95% CI: 0.94-1.27) for parity >2, 1.20 (95% CI: 1.03-1.40) for miscarriage/abortion, and 2.16 (95% CI: 1.41-3.31) for artificial menopause and protective effect (RR: 0.78; 95% CI: 0.65-0.92) for prolonged use of OCs.

Conclusions: This meta-analysis supports an association due to changes in female hormones during menstrual cycle and pregnancy with the risk of TC and explains female preponderance.

Keywords: meta-analysis; oral contraceptive use; reproductive factors; thyroid cancer.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Abortion, Spontaneous / epidemiology
  • Adolescent
  • Adult
  • Age Factors
  • Case-Control Studies
  • Cohort Studies
  • Contraceptives, Oral / adverse effects
  • Contraceptives, Oral / therapeutic use*
  • Female
  • Humans
  • Menarche
  • Menopause
  • Menstrual Cycle
  • Middle Aged
  • Odds Ratio
  • Parity
  • Pregnancy
  • Reproduction*
  • Risk Factors
  • Thyroid Neoplasms / epidemiology*
  • Thyroid Neoplasms / etiology
  • Young Adult

Substances

  • Contraceptives, Oral