The director of the National Breast Screening Programme has called on women not to be alarmed by a study claiming that breast cancer screening is pointless and does not save lives.
Dr Jane Buttimer said that the study by two Danish experts, published in the current issue of The Lancet, would be "carefully scrutinised", but it "should not deter women from availing of being screened".
The Danish study, which subjected the results of eight breast cancer screening studies in four countries to further analysis, concluded that screening for breast cancer with mammography was "unjustified".
The State's recently launched Breast Check programme aims to reduce breast cancer mortality in women aged 50 to 64 by at least 20 per cent over the next decade by screening at least 70 per cent of women in the age group.
Close to 1,700 new cases of breast cancer are reported in the State every year, with an average of 635 deaths per annum. Ireland has the fourth-highest death rate in 25 countries studied by the World Health Organisation.
The Danish study was not a new one, Dr Buttimer said, but "simply a reworking of old data". She emphasised that the technology had advanced significantly since these earlier studies had been carried out.
Dr Peter Gotzsche and Mr Ole Olsen, from the Nordic Cochrane Centre in Copenhagen, maintained that all but two of the eight studies of the effectiveness of breast cancer screening which they had looked at were unreliable. They said claims that mammography screening could reduce the risk of death by as much as a quarter were not borne out.
Dr Gotzsche said on BBC radio that the only two trials in the study which had been properly carried out "did not find an effect on breast cancer mortality, not even a tendency to an effect, as a result of screening".
He said that screening could cause harm by producing false alarms which resulted in some women having healthy breasts needlessly removed.
Dr Buttimer said that while breast cancer could not be prevented, early detection was vital if doctors were to alter the course of the disease. "Screening does find small tumours and this allows treatment in the early stages and the prospect of less radical and aggressive treatments", she said.
In another article in The Lancet, Dr Harry de Koning, from the Rotterdam department of public health, criticised the Danish experts for ignoring a number of important factors and challenged their opinion of what constituted a "biased" trial. He said there had been a "clear reduction in breast cancer mortality" in the UK, which was due in part to the national screening programme.
