Unbalanced estrogen metabolism in thyroid cancer

Well-differentiated thyroid cancer most frequently occurs in premenopausal women. Greater exposure to estrogens may be a risk factor for thyroid cancer. To investigate the role of estrogens in thyroid cancer, a spot urine sample was obtained from 40 women with thyroid cancer and 40 age-matched controls. Thirty-eight estrogen metabolites, conjugates and DNA adducts were analyzed by using ultraperformance liquid chromatography/tandem mass spectrometry and the ratio of adducts to metabolites and conjugates was calculated for each sample. The ratio of depurinating estrogen-DNA adducts to estrogen metabolites and conjugates significantly differed between cases and controls (p < 0.0001), demonstrating high specificity and sensitivity. These findings indicate that estrogen metabolism is unbalanced in thyroid cancer and suggest that formation of estrogen-DNA adducts might play a role in the initiation of thyroid cancer. What's new? Women with thyroid cancer have more estrogen-DNA adducts than women without, suggesting that the structures play a role in cancer development. Previous studies have suggested a link between breast cancer and thyroid cancer. When estrogens are metabolized, the resulting chemicals can bind to DNA; some of these metabolites damage the purine bases and cause mutations which lead to cancer. This study showed that women with thyroid cancer have a higher proportion of these DNA-damaging metabolites.