Continue Routine Screening After False-positive Mammo Result

Screening mammograms, often associated with false-positive results in breast cancer-free women, may indicate underlying pathology that still could result in breast cancer, according to a study published today in the Journal of the National Cancer Institute.

It was not known if women whose tests show findings that lead to a false-positive may be at higher risk of developing breast cancer than women who do not test false-positive. After a diagnostic work-up eliminates a cancer diagnosis, the women are encouraged to continue with routine screening, but they may be reluctant to do so.

To evaluate the risk of breast cancer and ductal carcinoma in situ in women between the ages of 50 to 69 who had received false-positive mammography results, researchers from the University of Copenhagen gathered data from a long-standing Danish population-based screening mammography program that took place from 1991 to 2005.

The researchers found that women with false-positive results had a relative risk of breast cancer that was significantly higher than those who tested negative, even as long as six years after the initial screening.

In comparing women who tested negative with those who received false-positive results, the researchers found that the negative-finding women had an absolute cancer rate of 339/100,000 person-years at risk, while those with false-positive results had an absolute cancer risk of 583/100,000 person years at risk. Person-years is defined as the product of the number of years times the number of members of a population who have been affected by a certain condition.

“Based on the findings in this study, it may be beneficial to actively encourage women with false-positive tests to continue to attend regular screening,” the researchers concluded.