Women Who Have Had False Positives on Mammograms May Be at Higher Risk of Breast Cancer

Mammogram false positives are relatively common. Research has found that after 10 years of regular screening, about 50% of women will experience one. This is true with both 3D and 2D mammography. A new study finds that though false positives are common, they’re also linked with an increased risk of actually developing breast cancer.

Research recently published in JAMA Oncology investigated the long-term outcomes of false positives. The study included data from roughly half a million Swedish women, about 10% of whom had received a false positive. Their health records were compared with 450,000 women of the same age and screening year, all of whom had also had clear screenings to that point.

The findings showed that the women who had false positives were about 60% more likely to end up developing breast cancer over a 20-year follow-up period. The researchers say their findings indicate that women with a history of false positives may want to be more focused on their screenings.

Xinhe Mao, first author and postdoctoral researcher at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet in Sweden, says, “It’s important to accentuate a long-term awareness of breast cancer in women who get false positive mammography results. It might be beneficial to draw up personal monitoring programmes for these women with careful follow-ups over the years immediately following.”

The team found that the risk was highest for the first four years following the false positive. After 20 years, though, 11.3% of the women who had a false positive developed breast cancer, compared with 7.3% of those who had not had a false positive. The higher risk was even more pronounced for the 60 to 75 age group.

The researchers also looked at breast density, which is a breast cancer risk factor. Though dense breasts are linked with a higher risk of cancer overall, in this study, those with lower density saw a higher rate of developing the disease after a false positive.

Death rates were investigated, as well, with the team finding that those who had had a false positive were 84% more likely to die of breast cancer.

The researchers say that their findings show that there may be certain risk factors that make someone more likely to develop breast cancer after a false positive, and doctors could use the study to help make personalized screening plans focused on these risk factors.

The team also stresses the importance of continuing to screen.

Kamila Czene, study co-author and professor at Karolinska Institutet, says, “Radiology and breast cancer screening are currently in a phase of rapid development, partly thanks to the use of AI. Our published paper is part of the general efforts to achieve better screening results and increase the screening programme uptake.”

To read more research on the prevalence of false positives, click here.