Despite screaming headlines, England’s breast cancer screening computer glitch didn’t kill anyone

A bureaucratic snafu in England has generated international headlines bemoaning the deaths of hundreds of women.

Some coverage, such as this CNN story picked up by KSAT in San Antonio, brought visions of a mass casualty event on the scale of a terrorist attack or airline crash:

Dozens of other news outlets chimed in with similarly explosive framing:

• Washington Post: The U.K. failed to tell thousands to get breast cancer screenings. Hundreds may have died as a result.
• Reuters: Breast cancer screening failure may have shortened 270 lives in England
• US News & World Report:  Breast Cancer Scan Error May Have Led to Death of 270 Women in England

The coverage focuses on a computer error at the National Health Service that caused some 450,000 older women (ages 68 to 71) not to receive scheduled invitations for a mammogram.

As a result, the stories claim, between 135 and 270 women may have died from breast cancer that could have been detected and treated earlier with lifesaving results. UK Health Secretary Jeremy Hunt is referenced as the source of these figures.

Lack of mammograms has never killed anyone

What’s the problem with these stories?

For starters, neither breast cancer screening nor any other form of cancer screening has been shown to reduce overall mortality, which is the best measure of whether lives are actually being saved or not.

For this reason, no one can say with any certainty whether mammograms would have saved these women — or whether the lack of a mammogram killed them.

Breast cancer screening has been shown to modestly reduce deaths from breast cancer. (About 1,000 50-year-old women need to be screened for 10 years to prevent one death from breast cancer.) However, this small benefit evaporates when other causes of death, such as cardiovascular disease, are factored in.

Why is this important? It’s possible that for some women, radiation and other toxic therapies that are used to treat screen-detected cancers may ultimately increase the likelihood of dying earlier from some other cause–canceling out any reduction in deaths from breast cancer.

That’s why it’s treacherous to consider lives “saved” by a reduction in deaths from a specific disease. The treatment of that disease may ultimately increase deaths through some other unrelated mechanism.

Overdiagnosis not accounted for

Another problem with this coverage is that it doesn’t adequately acknowledge the risk of overdiagnosis — the detection of cancers that never would have caused health problems or death. Some cancers are slow-growing and might never pose a risk to the patient, while others are very aggressive and may spread despite the earliest possible detection and treatment.

A recent Danish study estimated that about one-third of all mammography-detected breast cancers represent overdiagnosis. This means that women treated for these cancers had no chance to benefit, but experience all the harms of cancer treatment that may include surgery, chemotherapy, and radiation.

‘Epitome of disease-mongering’

Christine Norton, president and co-founder of the Minnesota Breast Cancer Coalition and a breast cancer survivor, called the headline and first paragraph of KSAT’s CNN story “the epitome of disease mongering.”

“Combined they engender fear not only in older women in the UK who were among those not invited to be screened but also in any woman of any age who has thought about the possibility of breast cancer,” she said.

UK Health Minister Jeremy Hunt addresses Parliament.

Norton said it was inaccurate and irresponsible to blame up to 270 deaths on a failure to invite women for breast cancer screening. “The more accurate and responsible statement is the quote in paragraph 5 [of the CNN story] by the UK Health Secretary, Jeremy Hunt, who noted that ‘At this stage it is unclear whether any delay in diagnosis will have resulted in any avoidable harm or death.’ Based on multiple studies, it’s more accurate to state that breast cancer screening results in false positives, over-diagnosis, and over-treatment.”

The point is not that mammograms are useless and should be avoided — it’s that the benefits are probably smaller than most women have been led to believe, and that those benefits are accompanied by significant harms that many women have never been warned about. Women are making decisions about mammograms based on incomplete, imbalanced information. News coverage of mammograms doesn’t help when it reinforces misconceptions about the effectiveness of screening and doesn’t address the harms.

Who will be notified?

According to the CNN coverage, “Health officials will contact the next of kin of women who are thought to have missed a scan and subsequently died of breast cancer, Hunt said. They will apologize and offer a process to establish whether the error led to an earlier death, and if compensation might be payable.”

This statement raises some interesting questions:

• Will officials also contact women who weren’t notified and let them know that they may have been spared unnecessary and harmful treatment that might have been prompted by a positive screen?
• Will they also apologize to the women who were notified and whose screen-detected tumors were treated unnecessarily? Will they inform those women of the significant chance that their cancer was overdiagnosed?

None of the superficial stories that I read about this situation asked these legitimate questions.

They missed an opportunity to bring balance to what is typically a one-sided message about breast cancer screening.

Editor’s note: A previous version of this story referred to “the UK’s breast cancer screening computer glitch” in the headline. References to a “UK” glitch have been changed to “England,” since the glitch only affected women in England and not Scotland, Wales, or Northern Ireland.