This is a very important book that has been almost completely ignored although it has wide range implications
regarding personal choices, practice of medicine and public policies.
We are terrified by death and sickness, probably more so than at any other time in history. We will accept almost any deal with our doctor if he or she promises that is good for our health. And we accept endless tests (diabetes, cholesterol, cancer screening) because it is good for us. Or is it really?
Welch tackles cancer screening and shows how it is probably not good for us.
Dr. Welch starts by reminding us that deaths caused by cancer are rare. Take for instance a random sample of 1,000 women at 50. How many will die from breast cancer in the next 10 years? He points out that only 6 will. If (and it is a big if) we take at face value the claim that cancer screening (by mammography) reduces this death rate by 1/3 then cancer screening would save 2 lives. As pointed out by Dr. Donald Berry (a well known Biostatistician with the University of Texas who is in favor of mammography) the benefit (if any) of regular mammographies is at best small. The average additional life for a woman that undergoes regular screening is 3 (three!) days (see his paper in International Journal of Epidemiology (2004), vol. 33, p. 68). This is so because breast cancer deaths are rare. They do increase with age but they remain rare (of 1,000 women at 70 only 13 will die of breast cancer in the next 10 years).
What is the cost of screening? There are monetary costs of course but let's concentrate on quality of life costs. About 8% of mammograms are found to be abnormal but fewer than 10% of women with abnormal mammograms have breast cancer. Even among those who are found to have breast cancer how many would have lived happily without ever knowing that they have a cancer if they had not been screened? There is clearly an explosive growth of women being treated for breast cancer due to cancer screening. Dr. Berry points out that there has been an increase of more than 50% in breast cancer since the advent of widespread screening. I will soon be 50 and I know several women around my age that have already been treated for breast cancer. Surely, not all these women were at risk from dying from the disease. Otherwise, breast cancer deaths would not be rare events. It is pretty clear that many more women than necessary are being treated for breast cancer. I have concentrated on breast cancer for this review but Welch examines the records of all other screening programs (prostate or skin cancer, for instance) and shows that they are at least as dismal. As Dr. Welch points out 'instead of making sick people well we make well people sick'.