X-rays and cancer

Ask the doctor| Mail Online

Ask the doctor: Should I be worried about X-rays giving me cancer?

By Dr Martin Scurr

On a recent appointment for a mammogram, I was told I’d be given two X-rays of each breast, but instead of four I was given six altogether. I am concerned at the amount of radiation I’ve been given. Couldn't this in itself cause breast cancer?

Linda Owen, Liverpool
Radiation worries: Studies show that when we weigh up the risks against the benefits, the analysis is in favour of using x-rays

Radiation worries: Studies show that when we weigh up the risks against the benefits, the analysis is in favour of using x-rays

Your anxiety is understandable, and you’re not alone in your concern that the X-rays used in mammogram examinations could cause cancerous change in breast tissue.

Indeed, it is known X-rays potentially damage the genetic material in cells and bring about malignant changes. However, I hope I can put your mind at rest, despite your recent experience.

The most important point is that cancer caused by radiation is dose-dependent — the more you receive, the higher the risk of genetic mutations. The amount of radiation needed for a mammogram is very small.

In fact, the amount of radiation you receive with four mammogram X-rays is about the same as the amount you experience in an aircraft flight over the Atlantic.

Radiation coming at the Earth from space is mostly absorbed by the atmosphere, and so you’re exposed to more when travelling at 35,000 ft.

With the six exposures during your mammogram, you’d have absorbed half that amount again — in total, about the amount of radiation you experience in a single X-ray of the chest.


The damage caused by X-rays is cumulative, adding up over the years. Despite this, studies show that when we weigh up the risks against the benefits, the analysis is in favour of regular screening mammograms.

The NHS breast cancer screening policy is to offer mammography every three years to women from the age of about 50. But I believe they should be also conducted in women in their 40s.

Of the 9,000 women who get breast cancer each year under the age of 50, only 2 per cent are diagnosed by screening. But in women of 50 or older, 55 per cent of cancers are detected by the screening programme.

And we know that if a breast cancer is detected by screening, the prognosis is twice as good due to the fact that the cancer is caught so much earlier.

What this tells us is that screening of women in younger age groups is valid. By 2013, the Government plans to extend screening to those who are 47 and older, which is at least a start. And new technologies offer advances.

By using digital photography for mammograms, the radiation dose is 22 per cent lower than that of conventional X-ray film mammography because less radiation is required.

Further, in younger women, who have denser breast tissue due to the higher levels of the hormone oestrogen in their systems, digital mammography can detect significantly more cancers.

This means that in this group of patients fewer small cancers are missed — by at least 25 per cent — compared to the older technique of film mammography.

In summary, be confident about what happened to you. There’s no need to worry.