Familial Risk Factors in Thyroid Cancer Across Generations and Geographics: A Systematic Review and Meta-Analysis.

Area of Science:

• Oncology
• Genetics
• Epidemiology

Background:

• Global thyroid cancer incidence is rising, necessitating a clear understanding of risk factors.
• Family history is a known risk factor, but its precise impact across different relationships and regions requires clarification.

Purpose of the Study:

• To systematically review and meta-analyze the association between family history and thyroid cancer risk.
• To clarify the magnitude of risk based on familial relationship types and demographic factors.

Main Methods:

• Systematic literature search of PubMed, Web of Science, and Embase following PRISMA guidelines.
• Inclusion of 13 studies from 503 initially screened.
• Random-effects models used for meta-analysis to calculate pooled odds and risk ratios, with subgroup analyses.

Main Results:

• Individuals with a family history of thyroid cancer exhibit an approximately 4.5-fold increased risk.
• Risk was notably higher for individuals with affected siblings; risks from maternal and paternal history were comparable.
• Socioeconomic, educational, lifestyle factors, and geographic variations did not significantly alter familial risk, despite high heterogeneity.

Conclusions:

• Family history is a substantial risk factor for thyroid cancer.
• Findings support enhanced surveillance and screening for individuals with a familial predisposition to thyroid cancer.