Mammography controversy needs greater participation to inform decisions

A major session at the World Congress on the Menopause has debated the benefits and risks associated with regular mammography. The potential benefit of mammography is earlier detection of breast cancer, but increasing evidence has shown that mammography also uncovers some cancers which would not go onto cause any problem, and many doctors believe that this overdiagnosis can cause real harm through unnecessary treatment . The debate in the scientific press has led to confusion in the minds of many women, who hope for a definitive answer on whether or not they should undergo regular mammography.

Now two prominent doctors from opposing sides of the debate have agreed that women need to be more involved in making decisions on whether or not mammography is right for them.

Dr Eugenio Paci presented work from the EUROSCREEN working group, showing that overdiagnosis is at the lower end of the estimates, indicating that mammography saves lives. This work indicates that screening 1000 women saves up to 7 lives, with only 4 overdiagnosis. Professor Robin Bell presented an analysis showing that up to 40% of invasive breast cancer cases identified in women invited for mammography may be overdiagnosed, and says that the total number of deaths in screened patients does not drop when measured against non-screened patients, indicating that screening has few benefits.

However, both doctors called for changes in the way mammography is dealt with.

Eugeni Paci (Florence, Italy) said: "There has been a lot of press interest in the pros and cons of mammography, and women need to be able to make sense of this. Our analysis shows that mammography saves lives, but we know that a certain amount of overdiagnosis exists: this is effectively a potential medical harm. Women need to be able to discuss the use of mammography and any treatment, to allow them to make decisions which are right for them, and we would urge healthcare providers and doctors to allow women to take more involvement in these important choices: they need to be more involved in the decision making process, so that if they do go ahead with regular mammography then they can feel comfortable about their decision. We also need a better understanding of just how aggressive- or not -- a cancer might be, so more research on this is urgently needed.

The problem is not really with the screening, it's what you do when it looks like you have found something suspicious. But I believe that screening needs to continue and to be improved."

Professor Robin Bell (Melbourne, Australia) said: "I think that it is time for a review of the routine invitation of women for screening mammography. When women receive an invitation for screening mammography they reasonably assume that on balance the benefits for them outweigh the risks. If there was no routine invitation for screening, then the onus would be on the woman to pursue screening and she could discuss in detail the pros and cons of screening with her health care provider. This would encourage the presentation of balanced information about the benefits and harms of screening and ensure women give truly informed consent for the procedure."

In a joint statement, both doctors joined in saying that "Women and doctors need to move to a new, more inclusive way of communicating the risks and benefit of mammography."

Commenting for the International Menopause Society, Professor Susan Davis (Melbourne, Australia) said: "Women need to be aware that almost nothing in medicine is either completely good or completely bad -treatments which benefit will have potential side effects. The variables are complex, and we are unlikely to get definitive data which says yes or no to mammography, so we need to make decisions based on what we have. These are not just physical health issues, the possibility of contracting breast cancer is highly emotive for many women -- it's the disease women fear the most, even if it's not the biggest killer. This shows that there are limits to what can be achieved by relying only on evidence based medicine. Doctors need to take time to explain the evidence to women, but also what this means, so that women can make an informed choice."