SUMMARY – Th e aim of the study was to assess the role of the estradiol and progesterone relationship
during the late luteal phase and the occurrence of fi brocystic breast disease (FBD). Th e concentration
of estradiol/progesterone was measured in the group of women with FBD as study group
(n=50) and control group of women without FBD (n=40). All women had regular ovulation cycles.
Blood samples for estradiol (E2), progesterone (P) and prolactin determination were obtained in the
morning at 8 am on days 21 and 24 of menstrual cycle. Signifi cant mastalgia and mastodynia history
in women with FBD was obtained with yes or no questionnaire. FBD diagnosis was confi rmed with
ultrasound (size and number of simple cysts). In the control group, a reduced E2/P ratio was noticed
from day 21 to day 24 of the cycle (from 14.8±11.5 pg/mL to 9.1±6.1 pg/mL; p<0.05), which was
not recorded in the group of women with FBD (study group). Even the slightest disturbance of the
E2/P ratio may contribute to the occurrence of FBD with clinical manifestations of mastalgia and
mastodynia.
