Ireland has had the 10th highest reduction in mortality from breast cancer at all ages among 31 European countries since 1987, according to new figures.

Ireland has seen a 32% drop in breast cancer death rates over the past 33 years, according to research presented at the 9th European Breast Cancer Conference in Glasgow.

The conference was told there have been sustained decreases in breast cancer mortality in Europe since the late 1980s.

The biggest drop in death rates was recorded in England and Wales, at 41%, with the second biggest reduction recorded in Scotland, at 38%. Breast cancer mortality actually increased by 11% in Romania over the past three decades.

Ireland's breast cancer death rate in women under 50 has dropped by 50% since the late 1980s, the 10th highest drop among European countries.

Prof Phillipe Autier from the Internal Prevention Research Unit at Lyon, in France, told the conference that while the decrease in breast cancer deaths in 2010 were greatest in those countries with the highest mortality rates in the 1980s, there were notable exceptions.

He pointed out that France, which has a highly organised breast screening programme has the highest spend on cancer drugs in Europe, and is to the forefront in use of new treatments, has seen only a modest drop in its breast cancer deaths since the late 1980s.

The lowest level of breast cancer mortality reduction in Europe in women over 50 was seen in France, according to the research.

Prof Autier's research shows that breast cancer mortality rates in France have only decreased by 17% since the late 1980s.

Similarly, Sweden, which has devoted major resources to screening, has seen little change in overall death rates, only 24% in 30 years.

Prof Autier pointed out that in Norway, breast cancer mortality dropped by 34% in the same period, despite nationwide screening being introduced 15 years later there than in Sweden.

It was found that many countries that implemented breast screening after 2000 had a higher reduction in breast cancer deaths in recent years than those that introduced screening back in the 1980s.

Prof Autier said further investigation was needed into why these differences in mortality reductions existed.

He said one explanation could be due to the fact that screening has had the effect of decreasing the average size of breast tumours at detection.

Prof Autier said that the incidence of advanced breast cancer has at the same time remained stable, suggesting that screening does not succeed in detecting potentially life-threatening cancers at an earlier stage, and the number of breast cancers that have already spread to other organs when first diagnosed have not decreased.

"Hence, these reductions in tumour size simply represent the increasing incidence of small, early, non- life-threatening cancers that are detected by screening, which give an overall impression that things are getting better in terms of outcomes."

"As a result, we can say that decreased numbers of breast cancer deaths are largely due to improved treatments, not to screening," Prof Autier said.