That's the question being asked about medical diagnostics, particularly for breast and prostate cancer. We don't have answers. I have thought about this for twenty years and more.
I was diagnosed with breast cancer just after the more sensitive x-ray films started to be used, when I was in my early 40s. It was my first mammogram, and there was no palpable lump. The biopsy said that the cells looked aggressive, but most of the hormonal and other tests available now were not then.
So I had a mastectomy. Fortunately, my lymph nodes were clear, and that was before it was decided that everyone who had breast cancer had to have chemotherapy and/or radiation. That was the end of it.
But I kept wondering. I was coming out of a very unhappy situation, and I think that one's emotional state can affect one's body and that our bodies have abilities to take care of errors like cancer. It was a small cancer, with lots of surface area for my white cells or whatever to attack the cancer cells. I had only one data point. Was the cancer growing or declining? No way to know. But I knew that my emotional situation was much improved from the year before and the year before that.
Should I have taken a chance on getting another data point in six months? In retrospect, that might have been a useful thing to do and would likely, given the sort of cancer I had, probably wouldn't have endangered my life. But I didn't know that then. I wanted it OUT OF MY BODY.
I recommended that a friend get a mammogram six months after my diagnosis. She had what seemed to be the same kind of cancer. She died from it last year after many surgeries and chemo and radiation treatments.
The problem is that we still can't distinguish which is which. We've gotten better at it, but we still have a long way to go. So this decision, to recommend less screening, is a substitute for knowledge. None of the media reports say this.
The decision makes sense in a public health sense. It will save anxiety, surgeries, and money. But there is no way to know for any individual. It could be that my cancer would have gone away, or it could be that I would have found a lump later and it would have become much more invasive.
We can't distinguish the various types of breast cancer to know exactly how to deal with each one. We don't know why my friend's returned and mine didn't.
Until we can distinguish, the medical professions have to decide how to deal with diagnosing in a general way what they can't characterize in detail. This decision seems to be the best they can do right now. The conflict between an individual's desire to know their own health and the medical profession's inability to provide a diagnosis that points to the best treatment is profound. Some women in my situation may be worse off in a tradeoff for some women who will avoid the pain of a false positive.
The only way to get beyond these tradeoffs is to understand the disease better.