HRT Does Not Affect Recall Rates for Screening Mammography

WASHINGTON—A new study shows that asymptomatic women taking hormone replacement therapy (HRT) are no more likely than women not on HRT to need follow-up imaging after screening mammography, said Linda Moy, MD, clinical assistant, Department of Radiology, Massachusetts General Hospital, Boston.

Hormone replacement therapy increases breast density in as many as 30% of women taking it, regardless of age, Dr. Moy said at the 100th annual meeting of the American Roentgen Ray Society (ARRS).

“Denser breasts are more difficult to image,” she said. “There is a fear that as mammographic density increases, it could be hiding things.”

Previous retrospective studies have indeed suggested that women taking HRT are more likely to receive recalls for further x-rays after initial mammography screening. To pursue the issue further, Dr. Moy and her colleagues at Mass General analyzed a database of 25,297 asymptomatic women who had routine screening mammograms between May 1995 and September 1997.

A total of 6,504 women reported current use of HRT. Among these women, 482 (7.4%) needed follow-up imaging. Among the 18,793 women not on HRT, 1,386 (7.4%) were recalled, “the same as for women not on HRT,” Dr. Moy said.

Eight of the recalls for women on HRT (less than 1%) were the result of anomalies attributed to the hormone therapy itself, she said. These included multiple cysts or changes in breast density that appeared after the start of HRT.

Biopsies were not done to prove the association between the therapy and the conditions, but HRT is accepted as the “best explanation” for the conditions’ development, Dr. Moy said.

 The team has begun a prospective study of the same issue. “If our results are confirmed, it would eliminate a worry for every woman on HRT,” she said.