The use of screening ultrasonography in the evaluation of postmenopausal breast cancer patients on tamoxifen: Is endometrial echo thickness enough?

Abstract

This study addresses the efficacy of endometrial echo thickness and uterine volume in predicting endometrial histology in postmenopausal breast cancer patients on tamoxifen citrate. Sixty-four post-menopausal women with breast cancer using tamoxifen for at least 6 months were entered in the study. All subjects underwent transabdominal and transvaginal ultrasonography by a board-certified radiologist as well as having an office endometrial biopsy performed by a gynecologist. Twenty of the 64 patients were evaluated on two separate occasions at least 6 months apart. Histologic findings ranged from atrophic or inactive endometrium ( N = 29), proliferative endometrium ( N = 6), simple hyperplasia without atypia ( N = 9), and scant tissue insufficient for diagnosis ( N = 20). Endometrial echo averaged 10.6 mm (range: 1.2–25.0 mm), and mean uterine volume was 105 cm 3 (range: 12–600 cm 3). The correlation between histology and endometrial thickness was not significant ( r = 0.12, P = 0.34). However, the correlation between histology and uterine volume was statistically significant ( r = 0.31, P = 0.017). Both uterine volume and endometrial thickness were found to increase with duration of therapy but only uterine volume was found to correlate with the length of treatment. This study suggests that tamoxifen has a universal uterotropic effect stimulating myometrial as well as endometrial growth and, in addition, a uterine volume measurement may be more predictive of endometrial histopathology than endometrial thickness in this patient population.