(no subject)
An essay in this month's Health Affairs is compelling reading, at least for folks like me. In brief, the author describes the reasons why she, despite a positive family history, does not get an annual mammogram.
The following paragraphs encapsulate the argument nicely, I think:
"If 2,000 women are screened regularly for ten years, one will benefit from the screening, as she will avoid dying from breast cancer. At the same time, ten healthy women will...become cancer patients and will be treated unnecessarily. These women will have either a part of their breast or the whole breast removed, and they will often receive radiotherapy, and sometimes chemotherapy. Furthermore, about 200 healthy women will experience a false alarm. The psychological strain until one knows whether or not it was cancer, and even afterward, can be severe."
And:
"Another important fact from my friends at the Nordic Cochrane Centre: It has not been shown that women who undergo regular screening live longer than those who don’t. This information is available elsewhere in different forms, but I like the clarity and concision of the Nordic Cochrane Centre pamphlet-as well as its list of solid scientific references."
Both of these are from the Nordic Cochrane Center, an offshoot of the Cochrane Collaborative, probably the most respected outcomes and effectiveness research group there is. Cochrane Reviews are widely thought to be authoritative answers to the question "What is the best way to diagnose and treat/manage $DISEASE?" Note that because they're the best evidence there is doesn't mean it's what's *done*, but the evidence is available if you want to look for it. They have a recently done an analysis of breast cancer screening with mammography which I have yet to read, but which is essentially a redo of the work the USPSTF did a while back on mammography, when they scaled back their recommendations to great political uproar. They came to the same conclusion: mammography doesn't work as well as we think it does. We aren't good enough yet to know who should be screened and who should not, and screening may not do all the good we've ascribed to it.
And now the political problem. A *lot* of people have invested a *lot* of themselves, their scientific and professional careers, their volunteering lives, and their incomes, in the goal of increased and aggressive screening, early detection and treatment. Which, it turns out, may not work. But these folks have sunk a *lot* of themselves into those goals, including making those goals the focus of their work- from oncologists and surgeons who treat breast cancer patients (who basically treat people with breasts as if they all have cancer, either now or Real Soon Now), to cancer survivors who are going to be hard to convince that either they would have survived anyway, or they basically got lucky by having screening at *just* the right time, to the thousands of people who have devoted their volunteer efforts to increasing awareness and funding for breast cancer research and treatment. None of those people wants to hear they may have been wrong. That they may have spent their time fruitlessly, needlessly. Or that the work they have devoted themselves to (and make their living from) may be, not just a waste of time, but an active harm to many women who worry needlessly about having cancer, or worse, who are treated as if they have cancer when they do not.
So no one is hearing the Cochrane review, just as no one hears the one which says that surgery for back pain is wrong, or that reducing dust mites doesn't control asthma, or that any of a number of other things we do to control or treat disease don't work. And some politicians, quick to sense an opportunity to get in good with a large voting block (people with breasts, or who know someone with breasts), are happy to decry the review, or the USPSTF guidelines, as a ploy to reduce health benefits for vulnerable people (with breasts).
There is, really, a science of figuring out what works and what doesn't. It's called epidemiology, and its sister science, biostatistics. They both require really large data sets to chew on to give results anywhere near accurate, but when large data sets are available, they're really good at pulling some wheat out of that there chaff. And it turns out that mammography may be chaff, and maybe we shouldn't be shilling for it the way we have been.
Read the essay. It's thoughtful, well written, and enlightening.
The following paragraphs encapsulate the argument nicely, I think:
"If 2,000 women are screened regularly for ten years, one will benefit from the screening, as she will avoid dying from breast cancer. At the same time, ten healthy women will...become cancer patients and will be treated unnecessarily. These women will have either a part of their breast or the whole breast removed, and they will often receive radiotherapy, and sometimes chemotherapy. Furthermore, about 200 healthy women will experience a false alarm. The psychological strain until one knows whether or not it was cancer, and even afterward, can be severe."
And:
"Another important fact from my friends at the Nordic Cochrane Centre: It has not been shown that women who undergo regular screening live longer than those who don’t. This information is available elsewhere in different forms, but I like the clarity and concision of the Nordic Cochrane Centre pamphlet-as well as its list of solid scientific references."
Both of these are from the Nordic Cochrane Center, an offshoot of the Cochrane Collaborative, probably the most respected outcomes and effectiveness research group there is. Cochrane Reviews are widely thought to be authoritative answers to the question "What is the best way to diagnose and treat/manage $DISEASE?" Note that because they're the best evidence there is doesn't mean it's what's *done*, but the evidence is available if you want to look for it. They have a recently done an analysis of breast cancer screening with mammography which I have yet to read, but which is essentially a redo of the work the USPSTF did a while back on mammography, when they scaled back their recommendations to great political uproar. They came to the same conclusion: mammography doesn't work as well as we think it does. We aren't good enough yet to know who should be screened and who should not, and screening may not do all the good we've ascribed to it.
And now the political problem. A *lot* of people have invested a *lot* of themselves, their scientific and professional careers, their volunteering lives, and their incomes, in the goal of increased and aggressive screening, early detection and treatment. Which, it turns out, may not work. But these folks have sunk a *lot* of themselves into those goals, including making those goals the focus of their work- from oncologists and surgeons who treat breast cancer patients (who basically treat people with breasts as if they all have cancer, either now or Real Soon Now), to cancer survivors who are going to be hard to convince that either they would have survived anyway, or they basically got lucky by having screening at *just* the right time, to the thousands of people who have devoted their volunteer efforts to increasing awareness and funding for breast cancer research and treatment. None of those people wants to hear they may have been wrong. That they may have spent their time fruitlessly, needlessly. Or that the work they have devoted themselves to (and make their living from) may be, not just a waste of time, but an active harm to many women who worry needlessly about having cancer, or worse, who are treated as if they have cancer when they do not.
So no one is hearing the Cochrane review, just as no one hears the one which says that surgery for back pain is wrong, or that reducing dust mites doesn't control asthma, or that any of a number of other things we do to control or treat disease don't work. And some politicians, quick to sense an opportunity to get in good with a large voting block (people with breasts, or who know someone with breasts), are happy to decry the review, or the USPSTF guidelines, as a ploy to reduce health benefits for vulnerable people (with breasts).
There is, really, a science of figuring out what works and what doesn't. It's called epidemiology, and its sister science, biostatistics. They both require really large data sets to chew on to give results anywhere near accurate, but when large data sets are available, they're really good at pulling some wheat out of that there chaff. And it turns out that mammography may be chaff, and maybe we shouldn't be shilling for it the way we have been.
Read the essay. It's thoughtful, well written, and enlightening.