Prospective Study to Compare Endometrial Cytology and Transvaginal Ultrasonography for Identification of Endometrial Malignancies

Abstract

We compared transvaginal ultrasonography (TVS) and endometrial cytology by the Endocyte method for endometrial cancer screening. A total of 600 postmenopausal women who hoped for endometrial cancer screening (mean age, 61.1 ± 8.8 years; range, 44–87 years) underwent TVS, endometrial cytology (Endocyte method), and endometrial histology. The endometrial borders could be visualized by TVS in all women studied. However, cytology could not be performed in 59 women (9.8%) due to cervical stenosis. These 59 women were excluded from further study. Of the 541 remaining women, 38 had pathologic conditions (16 had endometrial cancer and 22 had endometrial hyperplasia). One (6.3%) of the 16 endometrial cancer patients and 10 (45.5%) of the 22 hyperplasia patients were asymptomatic. One hundred thirty-nine (83.7%) of the 166 women with postmenopausal bleeding had no pathological condition. When the cutoff value of endometrial thickness was set at 4 mm for women <5 years since menopause and 3 mm for those ≧5 years since menopause, TVS showed a 97.4% sensitivity, 75.7% specificity, 23.8% positive predictive value, and 99.7% negative predictive value. Thirty-seven of the 38 patients with endometrial disease were detected by TVS. Eight patients with a benign Endocyte examination were found to have endometrial hyperplasia. However, all endometrial cancers were detected by cytological examination. The Endocyte method exhibited 78.9% sensitivity, 95.4% specificity, 56.6% positive predictive value, and an 88.5% negative predictive value. In conclusion, TVS is thought to be useful for identification of patients who required further diagnostic investigation including endometrial histology.