ENDOMETRIAL EVALUATION IN POSTMENOPAUSAL BREAST-CANCER PATIENTS RECEIVING TAMOXIFEN - AN ULTRASOUND, COLOR-FLOW DOPPLER, HYSTEROSCOPIC AND HISTOLOGICAL STUDY

The purpose of this study was to evaluate the effect of tamoxifen ther apy on the endometrium by transvaginal color Doppler sonography, hyste roscopy and endometrial sampling. The study group (tamoxifen group) wa s composed of 38 asymptomatic postmenopausal women. All had been treat ed with tamoxifen (20-30 mg/day) for breast cancer for at least 1 year . The patients of the tamoxifen group underwent transvaginal color Dop pler sonography, hysteroscopy and, if necessary, endometrial biopsy. T hirty asymptomatic postmenopausal women (control group) and 25 asympto matic postmenopausal breast cancer patients not on tamoxifen therapy ( no-tamoxifen group) served as the control groups. The endometrium was scanned by transvaginal ultrasound to evaluate thickness, echotexture, border and intraluminal fluid. Color and pulsed Doppler were used to evaluate the pulsatility (PI) and resistance (RI) indices of the uteri ne and endometrial arteries when possible. The patients receiving tamo xifen had a significantly thicker endometrium compared to the control groups. Endometrial pathology was observed in 61% (23/38) of cases and an endometrial thickness of greater than or equal to 10 mm was always associated with an endometrial lesion. Nineteen benign endometrial po lyps were found most of them having a typical sonographic endometrial pattern with regular borders and small hypoechoic cystic areas which w e define as polypoid. Four endometrial hyperplasias, one of these atyp ical were observed. There were no endometrial cancers. The mean PI and RI of the uterine arteries in the tamoxifen group were 2.04 +/- 0.77 and 0.82 +/- 0.1, respectively and were significantly lower than those of the control group (2.93 +/- 0.9 and 0.93 +/- 0.06) and the no-tamo xifen group (2.53 +/- 0.7 and 0.89 +/- 0.1). The blood velocity change s were very similar to those described in postmenopausal women receivi ng estrogen replacement therapy. A correlation between the time of beg inning tamoxifen therapy after menopause and development of endometria l pathology was observed: in patients who started therapy many years a fter the onset of menopause, the risk of developing endometrial pathol ogy was higher than in those who began therapy a few years after the o nset of menopause. Patients receiving tamoxifen, particularly those wh o start therapy many years after the onset of menopause, should be clo sely monitored by transvaginal ultrasound and color Doppler imaging to detect endometrial lesions.