Friday, July 29, 2011

Screening has little impact on breast cancer deaths: study

Falling breast cancer death rates have little to do with breast screening but are down to better treatment and health systems, scientists said on Friday, in a study likely to fuel a long-running row over the merits of mammograms.

Researchers analysed data from three pairs of countries in Europe and found that although breast cancer screening programmes had been introduced 10 to 15 years earlier in some areas than in others, declines in death rates were similar.

The findings suggest that "improvements in treatment and in the efficiency of healthcare systems may be more plausible explanations" for falling deaths rates from breast cancer, they wrote in a study in the British Medical Journal.

World Health Organisation (WHO) data show that deaths from breast cancer are decreasing in the United States, Australia, and most Nordic and western European countries but breast screening is a hot topic among experts who disagree about whether nationwide mammogram programmes do more harm than good.

The fear among some is that over-diagnosis -- when screening picks up tumours that would never have presented a problem -- may mean many women are undergoing unnecessary radical treatment, suffering the physical and psychological impact of a breast cancer diagnosis that would otherwise not have come up.

But sweeping changes in U.S. guidelines two years ago that scaled back recommendations on breast screening caused an uproar among patient and doctors groups who said they put women at risk. That was swiftly followed by two conflicting European studies which further fuelled the row.

The first, by Danish scientists, found that breast cancer screening programmes of the type run by health services in Europe, the United States and other rich nations do nothing to reduce death rates from the disease, while the second, by a British team, found "substantial and significant reduction in breast cancer deaths" due to screening. (more)