Comparison of urinary and plasma hormone levels in daughters of breast cancer patients and controls.

Plasma and urinary levels of estrogens and progesterone were studied on days 11 and 22 of the menstrual cycle in 27 teenage daughters of breast cancer patients and 25 teenage daughters of controls. Plasma and urinary values correlated well, which implied that most previous findings based on urinary levels of these hormones were applicable to their plasma levels. The "estriol ratio" (urinary estriol:urinary estrone plus estradiol) hypothesis was not supported by this study, the ratio having been no lower in the daughters of breast cancer patients than in daughters of controls. The day-11 results showed elevated plasma prolactin-estrogen values in daughters of breast cancer patients; the day-22 results did not.