Endometrial thickness of postmenopausal breast cancer patients treated with tamoxifen.

The effect of administration time of tamoxifen was assessed in 52 postmenopausal patients with mammary cancer in order to evaluate its effect on endometrium and serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol. Mean age of the patients was 61.5 years, 23% had a history of smoking, mean body mass index (BMI) was 26.9 kg/m(2), and mean age at menarche, menopause and administration time of tamoxifen was 12.9, 48 and 3.5 years, respectively. Serum FSH and LH concentrations were decreased by 41.8% and 44.9%, respectively, compared with mean normal postmenopausal levels. The FSH decrement was associated with BMI and LH level, whereas the LH decrement was associated with patient age and FSH concentration. Endometrium thickness <5 mm was reported in 60.5% of the patients, while endometrium thickness >/=5 mm was found in 39.5% of the cases. Histology revealed that 75% of the patients had atrophic endometrium; the remaining patients (25%) did not show atrophic changes. Administration time of tamoxifen was not associated with endometrial thickness or with serum FSH and LH concentrations.