Use of Ultrasound for Endometrial Cancer Screening Is Weighed


SANTA MONICA, CALIF. — Transvaginal ultrasound has a specificity as high as 97% in screening asymptomatic women for endometrial cancer, but its use in the general population would result in a substantial number of false positives, according to a poster presentation at the biennial meeting of the International Gynecologic Cancer Society.

Using an endometrial-thickness cutoff of 10 mm or greater results in a 97% specificity and a 56% sensitivity, wrote Dr. Ian Jacobs of University College London and his colleagues. A cutoff of 5 mm or greater would result in a specificity of 86% and a sensitivity of 82%.

Using different cutoffs, depending on whether or not a woman used hormone replacement therapy, did not appreciably change the overall sensitivity or specificity.

The risk of endometrial cancer is associated with increasing weight, a history of breast cancer, and a history of any other cancer, but the study showed that limiting screening with transvaginal ultrasound to a higher-risk group of the population would result in only a slight increase in specificity.

Incorporating information on endometrial abnormalities can increase sensitivity somewhat, but at the expense of specificity. The investigators defined endometrial abnormalities as including polyps, fluid in the cavity, and/or thickened, cystic, irregular, or heterogeneous endometrium. Using the 10-mm cutoff for endometrial thickness and/or the presence of an endometrial abnormality resulted in a sensitivity of 73% and a specificity of 90% (compared with 56% and 97% without considering abnormalities).

The study used results from the U.K. Collaborative Trial of Ovarian Cancer Screening. Among the 38,668 asymptomatic women for whom transvaginal ultrasound results were available, 82 women were found to have endometrial cancer, including 5 with complex hyperplasia and 4 with atypical hyperplasia.

The investigators noted that current recommendations call for screening only women at especially high risk because of hereditary cancer syndromes. There is only limited enthusiasm for screening the general population, because endometrial cancer is found in stage I about 70% of the time and these patients have a relatively high 5-year survival rate of 85%. On the other hand, women diagnosed with stage Ic have a 5-year survival of 42%, and those with stage IV have a 5-year survival of 25%.

Screening of the general population would be expected to benefit those women but at the expense of significant false-positive rates that would result in some women having unnecessary diagnostic procedures.

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