“The largest threat posed by American medicine is that more and more of us are being drawn into the system not because of an epidemic of disease, but because of an epidemic of diagnoses. The real problem with the epidemic of diagnoses is that it leads to an epidemic of treatments. Not all treatments have important benefits, but almost all can have harms”*

I’ve learnt to my cost over the last decade or so, that whenever I write or speak about population-based screening for breast cancer by mammography I must start with this disclaimer:

“I have devoted my life to improving women’s health and I have been driven in part by the bad family history of breast cancer. Furthermore, I am one of the architects of the British National Health Service Breast Screening Program (NHSBSP) and understand the theory and process of screening.”

In this chapter, I wish to explain the paradox how in good faith I set up the service for the National Health Breast Screening Program (NHSBSP) in the South East of England in 1998 and since then become one of the most vociferous proponents for closing it down. I want to conclude this chapter by suggesting, that you the readers, can do more for women’s health than anyone involved in running the NHSBSP.

In 1987, the Forrest report was published just two weeks before a general election called by Margaret Thatcher; it having sat on her desk for six months.  This report was based on the review of all the available evidence that included two randomized trials plus three case control studies that predicted a 25% relative risk reduction (RRR) in breast cancer mortality favoring those who were invited to screening. (If the risk of something bad happening to you over say 10 years is 4% then a RRR of 25% is a 1.0% reduction) It is noteworthy that little space was allocated to the potential harms of population based screening by mammography.

Not surprisingly, the government of the day, endorsed the recommendations and promised that if re-elected a comprehensive screening program involving women 50-65 who would be invited every three years for mammography, would be established.

The NHSBSP was to be rolled out across the UK between 1988 and 1990. The service would be based on fixed screening units close to population of high density and mobile units for remote areas.

These district units would feed into a select group of regional specialist centers in major hospitals who would be provided with additional facilities and manpower to handle the predicted surge in activity following the first round of screening.

At that time, I was professor of surgery at Kings College Hospital, a major teaching hospital in South East London caring for a socially deprived population. Dr. Heather Nunnerly, head of diagnostic radiology, and I were given the dubious honor of setting up one of the first three centers in the country.

We were also given the task of setting up the training center for all the clinicians, radiologists and radiographers who would staff the other units serving the South East of England as the program was rolled out.

We were given 12 months to finish the job that was completed on time and on budget despite continuing with our full-time day jobs. I was proud of what we had achieved and in good faith, accepted the evidence available at that juncture. I threw myself into my leadership role in the NHSBSP and was rewarded by being offered a seat on the National committee running the show.

My love affair with the NHSBSP was short lived. Unlike most of the other members of the National Committee, I was directly involved in the day to day care of those women referred on to me because of the activities on the front line of the screening program. I found it very distressing to have to cope with otherwise well women who had popped into the screening unit for a mammogram at the invitation of the Department of Health (DOH) whilst doing their grocery shopping in Butterfly Walk Mall and then found themselves labeled as a cancer victim.

Worst of all were the unexpected high numbers diagnosed with duct carcinoma in situ (DCIS), a condition we rarely saw before screening began. Many of these cases were multifocal (scattered in little clumps all over the breast) and ended up with a mastectomy. How do you explain to a woman that she is “lucky”that we caught it “early”yet ends up having a mastectomy?

None of the DOH staffers or public health specialists on the National committee had to face the reality of these heart-breaking interviews. We were soon to learn that 20% of the cancers diagnosed in Butterfly Walk were DCIS, yet before we opened our doors, they amounted to less than 1.0% of our practice. I drew short term comfort from this observation assuming, that in the fullness of time, this initial peak in the incidence of DCIS would be followed by a fall in the incidence of invasive breast cancer. I couldn’t have been more wrong.

Within a few more years, others noted that the “interval cancer”rates were far too high to achieve the predicted 25% reduction in cause specific mortality. “Interval cancers”are those that appear as clinically detected lumps in the intervals between two invitations for screening examination.

These tend to be the fast-growing tumors that slip through the net. It rapidly became clear to me that we would never meet our targets and there was no evidence for the predicted fall of invasive cancers following the mopping up of all these cases of DCIS. Furthermore, updated analyses of the evidence in the Forrest report together with the publication of new trial reports, persuaded independent authorities to lower the estimate for the reduction in breast cancer mortality in a population-based screening program from 25% to 15%.

After six or seven years into the program, by which time it had been rolled out to the four corners of the UK, including the Islands and Highlands of Scotland, it became obvious to me that the benefits of screening had been grossly overestimated whilst the downside had been virtually