Early-Pregnancy Thyroid Autoimmunity Associated with Maternal Thyroid Cancer

May 6, 2024, by Jennifer K. Loukissas, M.P.P.

In an analysis of early-pregnancy sex steroid hormone and thyroid function markers in the Finnish Maternity Cohort, an international team of collaborators report a relationship between thyroid autoimmunity and risk of papillary thyroid cancer after pregnancy. Thyroid cancer is more common in women than men and is the third most frequently diagnosed cancer among women of reproductive age; greater medical surveillance in this age-group appears to explain only part of these patterns.

The research team, led by Cari Kitahara, Ph.D., senior investigator in the Radiation Epidemiology Branch, conducted a nested case–control study within the cohort to evaluate pre-diagnostic sex steroid and thyroid function markers in relation to subsequent maternal papillary thyroid cancer. In 605 women with papillary thyroid cancer, aged 18–44 years, and 1,185 controls (matched to cases by age, gestational age, and date of blood draw) who provided an early-pregnancy (<20 weeks gestation) blood sample, serum thyroid peroxidase antibodies (TPO-Ab) and  thyroglobulin antibodies (Tg-Ab) were associated with more than 3-fold and 2-fold increased odds of papillary thyroid cancer, respectively. These associations were similar by time since blood draw, parity, gestational age, smoking status, and age and stage at diagnosis. No associations were observed for the other biomarkers measured (thyroid stimulating hormone, free thyroxine, free triiodothyronine, progesterone, and estradiol).

Early pregnancy is a susceptible period for hormonal abnormalities including development of thyroid disease. These findings linking early-pregnancy thyroid autoimmunity with maternal papillary thyroid cancer may shed light onto mechanisms of thyroid carcinogenesis.

Reference

Kitahara CM, et al. Early-pregnancy sex steroid and thyroid function hormones, thyroid autoimmunity, and maternal papillary thyroid cancer incidence in the Finnish Maternity Cohort. Int J Cancer. 2024