Screening for breast cancer using mammography leads to a 21 per cent reduction in deaths from the disease, according to research published today.
A large Swedish study of almost 250,000 women who were followed up for an average 16 years showed the greatest benefit was for women aged 55 to 69.
The research, published in the medical journal, the Lancet, comes in the wake of a renewed debate about the merits of screening mammography. It will add to calls for a national extension of Breastcheck, the Republic's breast screening programme.
Dr Lennarth Nystrom and his colleagues at the University of Umea, Sweden, pooled data from four large randomised trials of mammography screening. They calculated the risk for breast cancer death and death from all causes for women given screening and also for those who were not invited for mammography.
The results showed that there were 511 breast cancer deaths in the screened group compared to 584 breast cancer deaths in women who did not undergo mammography. However, there was no significant difference in death from all causes between the two groups.
In an accompanying editorial, Dr Karen Gelman of the British Columbia Cancer Agency in Canada said: "These deaths confirm that women who are otherwise well, especially aged 55-69 years, and who are concerned about breast cancer, should be encouraged to attend screening. These women should attend about every two years. However, as breast cancer accounts for only 4 per cent of deaths annually, even a 21 per cent reduction in breast cancer mortality is barely measurable when death from all causes is the end-point."
Breastcheck has invited more than 67,000 women for mammography in the first 18 months of its operation. According to the clinical directors of the programme, Dr Fidelma Flanagan and Dr Anne O'Doherty, 357 breast cancers have been detected to date. This represents a detection rate of 8.5 per 1,000 women screened.
Results to date suggest that Breastcheck is on target to help reduce deaths by up to 25 per cent.While screening is now confined to women aged 50 to 64, The Irish Times understands that, even before the publication of today's research, serious consideration was being given to the extension of screening to those over 65.