Urine œstrogen profiles OF Asian and North American women

Abstract

Abstract Œstrone (El), œstradiol (E2) and œstriol (E3) were measured in the urine of Asian and North American women aged 15‐19, 20‐24 and 30‐39 years, during the follicular and luteal phases of the menstrual cycle. Each urine specimen was characterized by its œstriol proportion, E3/(E1+E2+E3). In each age group and cycle phase Asians had lower concentrations of œstrone and œstradiol and a higher oestriol proportion than North Americans. The differences were greatest in the youngest age group. Differences between the women from two North American cities or between women from three Asian areas were small. The data support the idea that the œstriol proportion, especially among young women, is a correlate of subsequent breast cancer risk.