A study published in the journal JAMA Internal Medicine looks at the pros and cons of breast cancer mammography screening.

That’s right, there are cons to breast cancer screening, because mammograms are not as precise as most of us think they are. The authors of the study conducted the research so that women can look at the numbers and decide for themselves whether or not they want to be screened. Current guidelines urge women over the age of 50 to have an annual mammogram.

Study Details

For the study, the researchers analyzed the likelihood of three possible outcomes of having a mammogram: avoidance of death from breast cancer, a “false alarm,” and over diagnosis followed by unnecessary treatment thru surgery, chemotherapy and/or radiation. They gathered information from various studies and came up with the following range of mammography tradeoff statistics per every 1,000 who begin annual mammograms at either age 40, 50 or 60 and continue them for a decade:

40 Year Olds

• Number of women who will avoid dying from breast cancer: .1-1.6
• Number of women who will have at least 1 false alarm: 510-690 (60-80 will have subsequent biopsies
• Number of women who will be misdiagnosed and treated needlessly with surgery, chemo and/or radiation: Up to 11

50 year olds

• Number of women who will avoid dying from breast cancer: .3-3.2
• Number of women who will have at least 1 false alarm: 490-670 (70-100 will have subsequent biopsies
• Number of women who will be misdiagnosed and treated needlessly with surgery, chemo and/or radiation: 3-14

60 year olds:

• Number of women who will avoid dying from breast cancer: .5-4.9
• Number of women who will have at least one false alarm: 390-54 (50-70 will have subsequent biopsies)
• Number of women who will be misdiagnosed and treated needlessly: 6-20

The authors of the study emphasize the fact that certainly if say, 100 people benefited from a mammogram while 50 had false alarms, the decision would be a no-brainer for most women. But the statistics don’t bear this out.

Additionally, the stress and anxiety that accompanies a false alarm can last for up to 3 years, according to some studies – that’s no small consideration.

Ultimately, the researchers concede that it’s up to each individual woman, along with her physician, to decide whether or not the benefits outweigh the harm of mammography screening.