Indices of differential endometrial: myometrial growth may be used to improve the reliability of detecting endometrial neoplasia in women on tamoxifen

The aim of this study was to test the hypothesis that the use of indices of differential endometrial: myometrial growth may be a non-invasive method of improving the reliability of detecting endometrial neoplasia in women on tamoxifen. Thirty postmenopausal women were involved in this prospective study. Nineteen had been treated with tamoxifen for 2 years or more, and eleven were age- and ponderal index-matched controls who had never been exposed to tamoxifen and who were non-smokers. Transvaginal ultrasonography and color Doppler imaging were performed, to measure the length, anteroposterior diameter, uterine sagittal area, endometrial thickness and uterine blood flow (using the pulsatility index and the resistance index as measures of uterine blood flow impedance). The anteroposterior diameter: endometrial thickness ratio and product, and the saggital area: endometrial thickness ratio and product were used as indices of differential endometrial: myometrial growth. The predictive values (sensitivity, specificity, positive and negative predictive values) of each index were calculated using established criteria. For the purpose of analysis the women were allocated to three groups: controls (group 1); women on tamoxifen without endometrial neoplasia (group 2) and women on tamoxifen who developed endometrial neoplasia (group 3). The mean age was similar in the three groups as was the duration of tamoxifen treatment in groups 2 and 3. Analysis of the decision matrix based on increased endometrial thickness (> 5 mm) alone revealed good sensitivity (100%) and negative predictive value (100%) but poor specificity (46.15%) and positive predictive value (26.32%). However, when the indices of differential endometrial: myometrial growth were taken into consideration, the sensitivities and negative predictive values were similar but the specificities and positive predictive values were significantly improved, indicating an improvement in the reliability of predicting the development of endometrial neoplasia.