Detection of endometrial cancer by transvaginal ultrasonography with color flow imaging and blood flow analysis: a preliminary report.

A prospective study was undertaken to assess whether changes in uterine blood flow could be used to detect endometrial cancer in 138 selected postmenopausal women (34 had uterine bleeding, 17 with endometrial cancer; 104 did not have uterine bleeding; 1 had endometrial cancer). Thirty-five of the asymptomatic women were receiving estrogen replacement therapy (ERT). The endpoints were endometrial (including tumoral) thickness and a pulsatility index (PI) derived from flow velocity waveforms recorded from both uterine arteries and from within a tumor. We found an overlap in endometrial thickness between those women with endometrial cancer and those without. The mean arterial PI value was invariably lower in women with postmenopausal bleeding and endometrial cancer (mean 0.91, range 0.31-1.49) than in those with other reasons for the blood loss (mean 3.83, range 1.95-6.40). The index was 1.10 in the woman with endometrial cancer but no sign of postmenopausal bleeding. Blood flow impedance was inversely related to stage of cancer. PI values in healthy women tended to increase slightly with age, but decrease during ERT. The detection rate was 100% within the limitations of the study design, and the false-positive rate was 1% for all women not receiving ERT and 11% for patients receiving ERT. Malignant tumors show signs of altered vascularization and a low PI (mean 0.49, range 0.29-0.92). We conclude that transvaginal ultrasonography, with or without color flow imaging, and blood flow analysis can be used to detect endometrial cancer in women with postmenopausal bleeding. A screening procedure for asymptomatic women must allow for changes in uterine blood flow during ERT.