There are a significant number of drawbacks to having consistent mammograms. Although your doctor may say that having a mammogram may reduce your risk of dying by 20 percent,1 you'd be surprised by how that percentage is calculated. As explained by Dr. Andrew Lazris and environmental scientist Erik Rifkin, Ph.D., for every 1,000 women who do not get mammograms, 5 will die from breast cancer. For every 1,000 women who do get regular mammograms, 4 will die.
The difference between those two groups is 20 percent, or the one person whose life is saved by getting a mammogram. Now, a new study from the Netherlands demonstrates that no matter how this number was calculated, it is likely not accurate.2 What's worse, the reverse side of the equation is that more women are actually harmed by the procedure or undergo unnecessary treatment as a result of false positives.
Mammograms Are Not Saving Lives
The study analyzed the reason fewer women are dying from breast cancer in the Netherlands after an aggressive screening program was instituted in 1989, including regular mammograms.3 Screening programs make the assumption that early detection is easier to treat and will result in better outcomes. Participants in the study were Dutch women who were screened every other year between 1989 and 2012. Nearly 8 million women were included in the data analysis.
The research was led by Dr. Philippe Autier from the University of Strathclyde Institute of Public Health. The intention was to determine if regular screening with a mammogram would affect the number of advanced cases of breast cancers detected and the number of deaths from the disease.4
In a previous study, in which the researchers used some of the same data, they found a decrease in the incidence of some advanced breast cancers that indicated the use of widespread mammography had been effective in reducing the number of deaths and improving early treatment. However, when the researchers expanded the analysis of the data, they failed to find the same reduction. During the period of the featured study, there had been no significant decrease in the extent of diagnosis of stage 2 to stage 4 breast cancers.5
Initially, the reduction in the number of women dying from breast cancer was attributed to a combination of environmental, lifestyle and genetic factors. These factors may have resulted in a 5 percent reduction between 1995 and 2012. Although the number of stage 0 and stage 1 cancers diagnosed increased sharply, the number of later stage cancers remained stable.6
Next, the researchers analyzed the data to determine what impacted the reduction in deaths from breast cancer if it wasn't an aggressive screening program. The researchers found that 85 percent of the observed decrease in deaths was related to improvements in treatment and not as a result of mammograms identifying lesions.
How Mammograms Work
A mammogram is an X-ray image of breast tissue, taken in the hopes of detecting abnormal cellular growth that may indicate breast cancer. The X-ray doesn't actually image a tumor growth, but rather looks for alterations in the tissue, which may be indicative of a tumor. It is also possible that some advanced tumors grow without expected tissue changes and thus go undetected.7
During a mammogram, your breast tissue is compressed against two plates to reduce the amount of tissue the X-ray must travel through, thereby reducing the amount of radiation needed and blurring from unintentional movement.8 The machine produces small bursts of ionizing radiation that may be read on film or digitally.
A newer type of mammography uses many low-dose X-rays as the machine moves over the breast. This imaging study is known as 3D mammography or breast tomosynthesis,9 during which the breast tissue is compressed once and a computer makes a 3-dimensional image. However, while this type of image may produce clearer results, you also receive greater amounts of radiation.
The issue with either a traditional mammogram or 3-D mammography is that you are exposed to ionizing radiation. This exposure carries significant health risks, including actually causing cancer and increasing your risk of breast cancer. Researchers have determined that women who carry the BRCA1/2 mutation may have greater vulnerability to radiation-induced cancers.10
Data suggests you have a 50 to 60 percent chance of receiving a false positive result after 10 yearly mammograms.11 Unfortunately, these positive results may lead to further mammograms, biopsies and sometimes to treatments, including partial mastectomy.12