Changes in the sonographic appearance of the uterus after discontinuation of tamoxifen therapy.
OBJECTIVE
The purpose of this study was to assess the duration of sonographically detected changes in the endometrium of women with a history of tamoxifen use.


METHODS
Patients with breast cancer who had a history of tamoxifen use and documented pelvic sonographic studies were identified by means of clinic databases in both the Section of Gynecological Oncology and the Section of Obstetrical and Gynecological Ultrasound, University of Chicago, between January 1, 1996, and March 30, 2004. Of the 99 patients who met study criteria, 34 had discontinued tamoxifen use before the sonographic evaluation. Each patient's age, gravity and parity, weight, ethnicity, duration and dose of drug use, interval from drug discontinuation until sonographic evaluation, and uterine pathologic findings were reviewed. Endometrial thickness as assessed by pelvic sonography was examined in relation to duration of tamoxifen use and time from discontinuation of the drug. Statistical analysis was performed with linear regression and mixed effect linear regression models.


RESULTS
Endometrial thickness increased with increasing duration of tamoxifen use at a rate of 0.75 mm/y. The mean endometrial thickness after approximately 5 years of tamoxifen use was 12 mm (range, 6-21 mm). After discontinuation of tamoxifen, endometrial thickness decreased by 1.27 mm/y.


CONCLUSIONS
Endometrial thickness as measured by pelvic ultrasound examination increases with the duration of tamoxifen use. After discontinuation of the drug, the measured thickness decreases but at a very slow rate.
Department of Obstetrics and Gynecology, University of Chicago, Chicago, Illinois, USA.
Mindy
M
Fishman
Mona
M
Boda
Eyal
E
Sheiner
Jacob
J
Rotmensch
Jacques
J
Abramowicz
D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage / Q000009:adverse effects; D001943:Breast Neoplasms / Q000188:drug therapy; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D004717:Endometrium / Q000000981:diagnostic imaging* / Q000187:drug effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011230:Precancerous Conditions / Q000139:chemically induced* / Q000000981:diagnostic imaging*; D013629:Tamoxifen / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D014463:Ultrasonography / Q000379:methods; D028761:Withholding Treatment
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen