Women who have false-positive results from their mammograms may have another reason to worry, a recent study says.
Researchers from the University of Copenhagen found that women who had a “false alarm” on their mammogram — an abnormal result that is further tested, often with biopsy, and then determined not to be cancer — had a 67% greater chance of developing breast cancer in the future, compared with women with normal mammogram results.
In the study, the researchers looked at more than 58,000 women aged 50 to 69 and found the risk of future breast cancer in women with false-positive screening results was significantly higher than in women with clean mammograms, even 6 or more years after the test. The findings don’t mean that women should stop breast-cancer screening, but that women with false-positive results should become more vigilant.
According to the researchers, women with false-positive results tend to have certain “suspicious patterns” in their breast tissue, such as tumor-like masses, microcalcifications, skin thickening or uneven density, which may put them at higher risk for future cancer, though the research is still inconclusive. “The excess breast cancer risk in women with false-positive tests may be attributable to misclassification of malignancies already present at the baseline assessment,” the authors suggest in their study.
The researchers recommend that women with false-positive results seek regular screening, acknowledging that this can cause further anxiety. After all, mammograms are getting some heat this week. On Monday, a Norwegian study found that mammograms may be overdiagnosing some early breast cancers, finding an estimated 15% to 25% of breast cancers that would not have caused problems during the women’s lifetime, but end up getting treated anyway.
“When you look for cancer early and you look really hard, you find forms that are ultimately never going to bother the patient,” Dr. H. Gilbert Welch of the Dartmouth Institute for Health Policy and Clinical Practice, who was not part of the research, told the AP. “It’s a side effect of early diagnosis.”
Still, there’s no question that early diagnosis saves lives overall and that differentiating between malignant and harmless cancers is difficult. “Until it is possible to differentiate which are bad and which are not, all need to be treated,” Dr. David Dershaw, head of breast imaging at Memorial Sloan Kettering Cancer Center in New York, told MSNBC.
So the back-and-forth over routine mammography continues, but for most women, the U.S. Preventive Services Task Force recommends mammograms every other year between the ages of 50 and 79. The American Cancer Society recommends more frequent screening, saying women over age 40 should get a mammogram every year.
The study was published in the Journal of the National Cancer Institute.