A hormonal association between estrogen metabolism and proliferative thyroid disease

OBJECTIVE: To illustrate a relationship between proliferative thyroid disease and estrogen metabolism through the analysis of urinary estrogen metabolites. STUDY DESIGN AND SETTING: Case-control study of 49 subjects with proliferative thyroid disorders and matching them to 49 controls. Urinary estrogen metabolite ratios were obtained, measuring 2-hydroxyestrone, an anti-proliferative metabolite, to 16 alpha-hydroxyestrone, a proliferative metabolite. The patients were stratified into low (0 to 1.00), medium (1.01 to 2.00), or high (> 2.00) groups according to their estrogen metabolite ratio. RESULTS: Fifty-one percent (25 of 49) of the cases had a low 2/16 ratio compared to 31% (15 of 49) in the control group while 20% (10 of 49) of the control group had a high 2/16 ratio as compared to 8% (4 of 49) in the case group (P value < 0.05). CONCLUSIONS: increased 16 alpha-hydroxyestrone activity compared to 2-hydroxyestrone activity appears to be associated with proliferative thyroid disease. SIGNIFICANCE: Further study of estrogen metabolites in relation to proliferative thyroid disease is warranted and may lead to implications for new treatment modalities for proliferative thyroid disease.