"I don't dare have my mammogram, I'm afraid of the X-rays." This concern comes up regularly in consultations. It deserves to be looked at using the available data rather than apprehension alone.

The myth

"Mammograms are dangerous because of radiation."

What the science says

Mammograms do indeed use X-rays, but at a very low dose. Mammography typically exposes the breasts to radiation of around 0.21 mSv. This is a minimal level of exposure compared with other radiological examinations.

Studies that have modelled this risk across large populations arrive at reassuring figures. The risk of developing radiation-induced breast cancer linked to mammography screening is generally considered to be around 1 case per 1,000 women screened over a 34-year period of participation in a screening programme. A model based on one hundred thousand women undergoing annual screening from age 40 to 55, then screening every two years up to age 74, illustrates this benefit-risk balance well: with an average glandular dose of 3.7 mGy per examination, the authors estimate 125 cancers attributable to radiation and 16 additional deaths, compared with 968 deaths avoided thanks to early detection — a benefit-risk ratio of around 60.

As for American recommendations, the number of deaths caused by radiation-induced cancer linked to mammography has been estimated at 2 per 100,000 women aged 50 to 59 screened every two years, and 11 per 100,000 women aged 40 to 49 screened annually. So this risk does exist, but it remains considerably lower than the number of cancers avoided through screening.

Why it matters

Learned societies recognise the overall benefits of mammography screening, such as reduced breast cancer mortality, while also taking into account possible drawbacks: false positives, anxiety, discomfort, overdiagnosis and radiation exposure. Letting fear of radiation take over can lead to postponing or avoiding an examination whose usefulness for early detection remains, to this day, well documented. The decision to be screened, and how often, should be made together with your doctor, taking into account your age and your personal risk factors.

What to remember

Key takeaway

The dose of X-rays used in mammography is very low, around two tenths of a millisievert per examination. The theoretical risk of radiation-induced cancer does exist, but according to available models, it remains far lower than the expected benefit of screening in terms of early detection.

Do not hesitate to raise this question with your doctor at your next appointment.