Mammogram False Positives Can Lead To Missed Screenings, Lack of Early Treatment: Study

Women who receive a false positive mammogram may be more likely to skip their next screening, or to delay important mammogram screenings, according to the results of new research that highlight the risks associated with misdiagnosis. 

In a study published this week in the medical journal Cancer Epidemiology, Biomarkers & Prevention, Illinois researchers report that false alarms about breast cancer have an impact on women, dissuading them from getting future screenings.

Researchers evaluated data from more than 650,000 true negative result mammograms, and nearly 91,000 false positive mammograms, from a total of 262,000 women in the Chicago-area.

The study indicated women who get a false positive mammogram are less likely to get their next mammogram. In fact, 85% of women with a true negative got their next scheduled mammogram, compared to 77% of women who received a false positive.

A false positive mammogram is when an abnormality is found in the breast. Often, the doctor will then recommend follow-up screening, including additional mammograms or biopsies, later to find it was a false alarm. They can even lead to a breast cancer misdiagnosis.

Women who have had a breast cancer scare are often advised to continue their screenings every year. The study indicated those women who received a false positive delayed their next breast screening by an additional 13 months, compared to women who had a true negative who delayed their screenings by only three months.

Among the findings of the new study, researchers indicated true negative patients were 36% more likely to return to get their next screening with the next 36 months. However, women who received a false positive often delayed the next screening even longer.

By delaying their follow-up mammogram, women face an increased risk of being diagnosed with late stage cancer, researchers warned. Those women had an increase in a four year cumulative risk of late stage diagnosis.

A study published last year indicated mammograms often lead to the over-diagnosis of breast cancer, which may result in unnecessary treatment, side effects or death.

The study revealed four times as many tumors that are not dangerous, but lead to aggressive treatment, are found because of widespread mammogram recommendations. This leads to unnecessary measures for small tumors, such as surgery, chemotherapy and radiation.

Another study published last month concluded one-third of women diagnosed with breast cancer are told their condition is worse than it actually is, causing unnecessary treatments for less invasive forms of cancer that typically call for the “watch and see” treatment.

Research published in 2015 indicated breast cancer misdiagnoses cost the U.S. $4 billion in unnecessary health costs, including false positives, misdiagnoses, and over-treatment of tumors that don’t pose a threat to women’s health.