Epidemiology of reproductive and hormonal factors in thyroid cancer: Evidence from a case‐control study in the Middle East

Abstract

Thyroid cancer is the second most common neoplasm among women in Kuwait and several other countries in the Middle East. Most of these countries also have relatively high birth and total fertility rates. To examine potential relationships between reproductive and hormonal factors and thyroid cancer, we conducted a population-based case-control interview study among 238 women diagnosed with thyroid cancer and a similar number of individually matched controls in Kuwait. Among the demographic variables, women with 12+ years of education had a significantly reduced risk of thyroid cancer (OR = 0.4; 95% CI: 0.2–0.8; p-trend p-trend <0.05). Overall, any female hormone use was not associated with thyroid cancer risk. New association is suggested for a history of post-partum thyroiditis (OR = 10.2; 95% CI: 2.3–44.8). These data support the hypothesis that reproductive factors and patterns may influence, or contribute to, the risk of thyroid cancer among women.