Surveillance for uterine abnormalities in tamoxifen-treated breast carcinoma survivors: a community based study

Tamoxifen-treated breast carcinoma survivors are at elevated risk of endometrial carcinoma. Whether to recommend annual surveillance for uterine abnormalities in this population is currently under debate.

This study was a cross-sectional, community-based investigation of tamoxifen use and the frequency of surveillance for endometrial carcinomas in 541 women with breast carcinoma. Study participants whose breast carcinoma was diagnosed in 1994 were interviewed in 1998. Data were collected from a telephone interview and from a cancer registry record. Tests for uterine abnormalities, based on participant reports of endometrial biopsy and transvaginal ultrasound, were categorized according to frequency. Testing for uterine abnormalities was defined as irregular if women reported tests once every 3 years, on average, and as regular, if they reported annual tests.

Forty-nine percent of respondents were current tamoxifen users, 12% were former tamoxifen users, and 39% reported never taking tamoxifen. Of respondents with a uterus (n = 385), 19% reported irregular and 30% regular testing for uterine abnormalities after their breast carcinoma diagnosis. Respondents more frequently reported transvaginal ultrasound (37%) than endometrial biopsy (29%). Women 65 years of age and older were significantly less likely to report regular surveillance for uterine abnormalities (16%) than those younger than 65 years (35%). Current tamoxifen users more frequently reported regular surveillance (43%) than either former (35%) or never tamoxifen users (15%). Multivariable analyses showed tamoxifen users were more likely to have regular (odds ratio [OR], 9.8; 95% confidence interval [CI], 4.4-21.8) or to have irregular testing for uterine abnormalities (OR, 3.9; 95% CI, 1.9-8.1) compared with women who never used tamoxifen, after adjustment for age, number of recent gynecologic visits, and gynecologic symptoms.

The results of the current study indicate that half of the breast carcinoma survivors in this population were tested for uterine abnormalities. Although at increased risk, 38% of tamoxifen users never had a test. Clear guidelines need to be established for the type and frequency of testing for uterine abnormalities among tamoxifen-treated breast carcinoma patients.