Breast cancer screening not shown to reduce deaths, say researchers

Breast cancer screening programmes have yet to show a reduction in the number of women who die from the disease, researchers say. A study suggests there is no evidence that screening women for breast cancer has an effect on mortality.

There has been fierce debate about the value of screening programmes. While mortality rates for breast cancer have significantly declined since the 1980s, some critics have said the screening programmes do more harm than good and lead to many women undergoing unnecessary surgery.

In response to the controversy, the Department of Health commissioned a review into the risks and benefits in 2011. The independent panel concluded there was a 20% relative reduction in mortality from breast cancer in women invited to screening.

But the latest research, published in the Journal of the Royal Society of Medicine, contests the findings.

The authors write: "We permuted the data in a number of different ways, over an observation period of 39 years, but the data show that, at least as yet, there is no evidence of an effect of mammographic screening on population-level breast cancer mortality."

The research analysed mortality trends across England before and after the introduction of the NHS breast screening programme in 1988.

Researchers from the department of public health at the University of Oxford also specifically looked at mortality statistics from the Oxford region because it was the only area in the country which recorded all causes of death on the death certificate, not just the underlying cause, at the start of the programme. They concluded that population-based mortality statistics for England do not show a past benefit of breast cancer screening.

Lead researcher Toqir Mukhtar said that while the new results did not rule out a benefit of breast cancer screening at the level of individual women, "the effects are not large enough to be detected at the population level".

"Measuring the effectiveness of mammography screening is a fundamental area of concern in countries which have established mammography screening programmes," she said.

"Clinical trials have indicated that several years have to elapse between the start of screening and the emergence of a reduction in mortality. Yet our data shows that there is no evidence of an effect of mammographic screening on breast cancer mortality at the population level over an observation period of almost 40 years." Lady Delyth Morgan, chief executive of the charity Breast Cancer Campaign, said: "While research into breast screening is welcomed, conflicting findings from different studies can be confusing for women.

"The most in-depth study of breast screening to date remains the recent independent breast screening review, which comprehensively looked at all available evidence. It concluded that screening does save lives by helping to detect breast cancers earlier.

"The quicker women are diagnosed the better their treatment options so we encourage all women to continue to attend screening when invited to do so."