Excretion of catecholestrogens in women receiving estrogen-substitution therapy

We compared excretion of classical estrogens and catecholestrogens in smoker and nonsmoker postmenopausal women receiving estrogen-substitution therapy. Combined effect of substitution therapy and smoking, but not smoking along increased production of catecholestrogens, which could enhance the risk of genotoxic (clinically more severe) variant of hormone-induced carcinogenesis.