Ultrasound characteristics of endometrial cancer as defined by International Endometrial Tumor Analysis (IETA) consensus nomenclature: prospective multicenter study

OBJECTIVE: To describe the sonographic features of endometrial cancer in relation to tumor stage, grade and histological type, using the International Endometrial Tumor Analysis (IETA) terminology. METHODS: This was a prospective multicenter study of 1714 women with biopsy-confirmed endometrial cancer undergoing standardized transvaginal grayscale and Doppler ultrasound examination according to the IETA study protocol, by experienced ultrasound examiners using high-end ultrasound equipment. Clinical and sonographic data were entered into a web-based database. We assessed how strongly sonographic characteristics, according to IETA, were associated with outcome at hysterectomy, i.e. tumor stage, grade and histological type, using univariable logistic regression and the c-statistic. Grayscale and color Doppler features varied according to grade and stage of tumor. High-risk tumors, compared with low-risk tumors, were less likely to have regular endometrial-myometrial junction (difference of -23%; 95% CI, -27 to -18%), were larger (mean endometrial thickness; difference of +9%; 95% CI, +8 to +11%), and were more likely to have non-uniform echogenicity (difference of +7%; 95% CI, +1 to +13%), a multiple, multifocal vessel pattern (difference of +21%; 95% CI, +16 to +26%) and a moderate or high color score (difference of +22%; 95% CI, +18 to +27%). CONCLUSION: Grayscale and color Doppler sonographic features are associated with grade and stage of tumor, and differ between high- and low-risk endometrial cancer.