Breast cancer screening - weighing up your choices

Despite the publicity around breast cancer survivor celebrities such as Kylie Minogue, the majority of women (about ¾) who get breast cancer are over 50

None of us like to think about reaching that age. Fifty may be the new 40 (I'm starting a campaign to make it the new 30 since it's looming ever larger on my personal horizon), but the menopause waits for no woman. And neither, of course, does breast screening. At some point in the three years after your 50 th birthday, that brown envelope with an invitation for a mammogram will drop onto your doormat. Most of my patients do accept, safe in the knowledge that it has to be a good thing. Now the latest news headline has given us pause for thought.

Breast cancer is possibly the condition more women fear than any other. That's partly because it's 'The Big C' - but there are lots of different cancers. It has, however, the dubious privilege of being the single most common cancer in the UK. One in eight women will be diagnosed with breast cancer in a lifetime, with over 48,000 UK women getting the bad news every year.

Despite the publicity around breast cancer survivor celebrities such as Kylie Minogue, the majority of women (about ¾) who get breast cancer are over 50. That's why all UK women are invited for regular breast screening with mammography every three years from the age of 50 to 70. The idea is that screening picks up cancers at an earlier stage, when they can't be felt and haven't produced any visible changes. The earlier the stage at which breast cancer is treated, the better the likelihood of long-term survival.

And a new review of the evidence on breast cancer screening shows that it does save lives, reducing the risk of dying of breast cancer by 20%. With more than two million women screened each year in the UK, it's estimated that one death is avoided for every 235 women invited for screening - 1,300 lives saved a year.

But there's a downside. The review also found that while most women will get the all clear, 681 women will be diagnosed with cancer for every 10,000 screening. Of these 681 cancers, 129 will be slow-growing cancers which wouldn't have done these women any harm and would never have been found otherwise. That means that about 4,000 women a year will be treated with surgery, radiotherapy and/or chemotherapy unnecessarily.

Unfortunately, we just don't know enough about breast cancer to work out which ones will grow and which ones can be left safely alone. Research is ongoing and we may have sophisticated tests to tease out the aggressive cancers from the less aggressive, but that doesn't help women making the decision now about whether to go for screening.

Should we be telling women at all, when it might worry them and put them off a potentially life-saving procedure? Of course we should. It would be incredibly arrogant of me as a doctor to decide a woman 'couldn't cope' with the whole picture. My job is to give her all the information she needs to make an informed decision. For a woman who isn't particularly worried about breast cancer, those figures might make the risk too big to take. For someone touched by cancer within their family, it could seem a small price to pay.

As for me - when that brown envelope comes through my door, in the light of these findings, will the contents end up in the bin or in my diary? Oh, I'll be there. I'm firmly in the 'small price to pay' camp.

Dr Sarah is unable to provide medical advice or respond directly to questions concerning your health. If you have health concerns we recommend contacting your GP.