Re: Ethnic Differences in Estrogen Metabolism in Healthy Women

Extract

We must take issue with the correspondence by Taioli et al. ( 1 ) concerning implications of ethnic differences in estrogen metabolism among healthy women of different races. Their claim that breast cancer risk is inversely related to the ratio 2-OHE2/16α-OHE1 conflicts with most of the basic endocrine carcinogenic studies and biochemical epidemiologic research over the last three decades ( 2 ). Pregnancy, which can be highly protective against breast cancer, is marked by a 1000–1500-fold increase in excretion of 16-αhydroxylated estrogens during the last 5–6 months. Estrogen analysis by product isolation of excretion rates by 1764 healthy women aged 15–59 drawn from worldwide sources show that estriol excretion was inversely related to cancer risk ( P <.02; Wilcoxon matched pairs, two-sided). An association existed between cancer risk and the racial mean rates of total catechol estrogen excretion ( 2 ). Adlercreutz et al. ( 3 ) found similar differences between Finnish and Japanese women using their precise gas chromatography-mass spectrometry analytic system.