title: Investigation of endometrial abnormalities in asymptomatic women treated with tamoxifen and an evaluation of the role of endometrial screening.
abstract: OBJECTIVE
  Tamoxifen is the most commonly prescribed adjuvant therapy for women with breast cancer. It has agonist activity on the endometrium and is associated with an increased risk of endometrial cancer. The aim of this study was to evaluate whether screening with transvaginal ultrasound (TV USS) with or without hysteroscopy is worthwhile.
  
  
  METHODS
  A total of 487 women with breast cancer, 357 treated with tamoxifen and 130 controls, were screened with TV USS, and endometrial thickness was measured. Women with thickened endometrium underwent outpatient hysteroscopy.
  
  
  RESULTS
  Length of time on tamoxifen ranged from 5 to 191 months (mean, 66 months), and endometrial thickness ranged from 1 to 38 mm (mean, 7.3 mm). Women treated with tamoxifen had significantly thicker endometrium than did controls (P <.0001). There was a statistically significant (P <.0001) positive correlation between length of time on tamoxifen and endometrial thickness. One hundred forty-five women had endometrium greater than 5 mm on USS, and 134 underwent successful outpatient hysteroscopy, 61 of whom had atrophic endometrium, resulting in a 46% false-positive scan rate. The remaining women all had benign features to explain the USS findings.
  
  
  CONCLUSIONS
  TV USS detects a high incidence (41%) of apparent endometrial thickening in women treated with tamoxifen, although 46% had atrophic endometrium on further assessment, and none of the remaining asymptomatic women had significant lesions. Length of time on tamoxifen relates to endometrial thickening as measured by TV USS. TV USS is a poor screening tool because of the high false-positive rate. The low frequency of significant findings suggests that endometrial screening in asymptomatic women is not worthwhile.
authors.affiliation: Edinburgh Breast Unit, Western General Hospital, Edinburgh, United Kingdom.
authors.forename: C D
authors.initials: CD
authors.lastname: Love
authors.forename: B B
authors.initials: BB
authors.lastname: Muir
authors.forename: J B
authors.initials: JB
authors.lastname: Scrimgeour
authors.forename: R C
authors.initials: RC
authors.lastname: Leonard
authors.forename: P
authors.initials: P
authors.lastname: Dillon
authors.forename: J M
authors.initials: JM
authors.lastname: Dixon
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy*; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000453:epidemiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D015907:Hysteroscopy; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013629:Tamoxifen / Q000009:adverse effects*; D014463:Ultrasonography; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen