False-positive mammogram results should not be dismissed too quickly. A new study says that these could actually indicate an increased risk for breast cancer. Researchers, led by assistant radiology professor Louise Henderson from the University of Carolina School of Medicine, reported that women who have had false-positive mammograms face the risk of developing breast cancer for up to 10 years after they got the results.
The research team studied data from the Breast Cancer Surveillance Consortium. The data, collected from 1994 to 2009, included more than 2 million mammograms done on 1.3 million women aged 40 to 74 years old. The researchers investigated the women's records after their mammogram screening and discovered that 48,735 of them were diagnosed with breast cancer within 10 years of being screened.
"Our finding that breast cancer risk remains elevated up to 10 years after the false positive result suggests that the radiologist observed suspicious findings on mammograms that are a marker of future cancer risk," Henderson said in a press release. "Given that the initial result is a false-positive, it is possible that the abnormal pattern, while noncancerous, is a radiographic marker associated with subsequent cancer."
In the U.S., 67 percent of women aged 40 years old and above go through mammogram screening every year or every two years. False-positive results are seen in 16 percent of initial screenings and in 10 percent of subsequent screenings. Within 10 mammogram screenings, there is a 61 percent chance of getting a false-positive result for women screened every year and a 42 percent chance for women screened every two years.
Of the women who get false-positive results, those who were referred for more imaging tests faced a 39 percent risk of developing breast cancer, while those who were referred for biopsies faced a 76 percent risk of having breast cancer within 10 years.
"A higher proportion of false-positive results were present among women with heterogeneously or extremely dense breasts compared with women who had almost entirely fatty breasts or scattered fibroglandular densities," Henderson said.
She emphasized that the results of their study are not meant to cause anxiety in women. "We don't want women to read this and feel worried. We intend for our findings to be a useful tool in the context of other risk factors and assessing overall breast cancer risk," she said.
The study was published online Dec. 2 in the journal Cancer Epidemiology, Biomarkers and Prevention.
