Menstrual cycle and hormone receptor status in breast cancer patients.

Hormone receptors in normal breast tissue were reported to be under the influence of cyclic variations of serum hormones during the menstrual cycle. The current study aimed to demonstrate a similar relationship between the phase of the menstrual cycle and hormone receptor status in operable, premenopausal patients with breast cancer. Patients were prospectively categorized according to the first day of last menstrual period into clinically defined follicular/luteal, perimenstrual/mid-cycle and unopposed estrogen/rest of the cycle phases and hormonally defined follicular/luteal phases. Serum follicle-stimulating hormone, luteinizing hormone, estrogen and progesterone levels were determined on the day of the operation. Estrogen and progesterone receptors in the tissues were detected by immunohistochemistry. Eighty-eight consecutive premenopausal patients with breast cancer were included in the study. Estrogen and progesterone receptors were positive in 57 (64.8%) and 40 (70.2%) patients respectively. Forty-nine patients were in follicular, and 39 patients in luteal phases according to serum hormone levels. Estrogen receptor positivity was significantly higher in hormonally defined follicular phase (p=0.025) and also had a tendency to be higher in perimenstrual phase (p=0.048). In contrast, progesterone receptor status was found to be independent of the phases of the menstrual cycle. As a conclusion, hormone receptor status might change during different phases of the menstrual cycle due to a possible effect of the circulating hormones and if it is found as negative, should he re-evaluated concerning the phase of the menstrual cycle in which the operation was performed.