However, one commenter notes:
How about a discussion of the ethics of this particular screening method since it's fairly equivocal whether it's actually worth the hassle and all the false positives in women aged 40?
I don't follow cancer diagnostics enough to be able to comment with any authority on that, so I'd be interested in hearing more from people out there with expertise in that area. However, a 2007 review and meta-analysis says this:
Meta-analyses of randomized, controlled trials demonstrate a 7% to 23% reduction in breast cancer mortality rates with screening mammography in women 40 to 49 years of age. Screening mammography is associated with an increased risk for mastectomy but a decreased risk for adjuvant chemotherapy and hormone therapy. The risk for death due to breast cancer from the radiation exposure involved in mammography screening is small and is outweighed by a reduction in breast cancer mortality rates from early detection. Rates of false-positive results are high (20% to 56% after 10 mammograms), but false-positive results have little effect on psychological health or subsequent mammography adherence. Although many women report pain at the time of the mammography, few see pain as a deterrent to future screening. Evidence about the effect of negative screening mammography on psychological well-being or the subsequent clinical presentation of breast cancer is insufficient.
Personally, I'd rather have to deal with a false positive than wait for a mammogram, but ideally the patient would be presented with the pros and cons of the screening procedure so they know what they're getting into. For me, the decrease in death rate justifies the potential false alarm, but others may be more freaked out than I am about a potentially positive result.
[Edited to add] And just as I publish this, Janet steps in with a follow-up post on the pros and cons of mammography for breast cancer screening in her age group (under 50). Go check hers out for more of the nuances...
I got a false result about 15 years ago years ago on my liver function and it really freaked me out for a few weeks even though I suspected it was incorrect. I think not only is the reate of false results important, but also the amount of time that passes before they are reversed. Much effort needs to go into speeding up retesting. Of course, I was in an HMO at the time. Maybe that was part of the problem.
Cancer, oh what a horrible disease
Yest, a scientist named Dr. Beard advanced the "Trophoblast" theory 100 years ago. Very intersting video called "a world without cancer" Where a nutritional defiency of b17 is the proposed cause
before I get attacked, I do not support this theory, for im not an expert in Cancer like I am in virology and 9/11 studies, so I don't know whether its true, just found it to be interesting, could be a sham I dont know.
Otac blogged on mammography "and all that" a little while back I think.
A line of argument I've heard, but never confirmed for myself, is that for younger woman the combination of the relative rarity of breast cancer in their age group and that it develops faster than the period between the tests, compared to older women, where development of the cancer is typically slower, means that testing younger women is less effective.
Don't rely on that, but it might be a starting point to check out.
The point is not whether screening in 40-49 saves lives which the meta-analysis seems to indicate (7% to 23% reduction). It whether it's worth paying all that money for that. One would normally say it is worth it to save lives. But would it be worth spending the GDP of the United States to have that sized reduction?
Mortality reductions do not automatically make the system worthwhile from the whole of society's viewpoint.
Anecdote time. My wife is in the 40-50 age group, her mammogram came back positive, the biopsy came back positive (stage 0--precancerous specks), she's going in for her second lumpectomy next week (the first missed the mark).
The doctor said that this is still in the slow-growth stage, that probably next year it would still be stage 0, but in five years it could get pretty nasty.
My wife was in the low risk group for cancer (no known family history, non-smoker) and mammograms are fairly painful for her (very little breast tissue, so they really have to tug to get it in the X-ray). So, her doctor had let her skip her mammogram last year.
When she told her parents about the positive result they told her about all her relations who had ended up with cancer--I guess either they were superstitious about talking about it before or didn't think it was something their children should know about (kind of in the "what you don't know won't hurt you" category).
So, I guess the moral of the story is that just because your family never told you about a history of cancer doesn't mean that there isn't one.
Tara, do you know much about Hendra viruses? If you do, I'd love your take on this:
(Bats are the reservoir, again, like in Marburg and Ebola.)
I've picked up that a couple of your articles in 2006 mention Hendra viruses in passing: I'll read these later tonight. Hope I'm not being a pest!
I don't recall the precise name of the study, though I recall it being published within the last 2-3 years. It was a longitudinal study comparing a control group of women screened with the usual methods, and another which got prophylactic mammograms annually - the purpose was to find the effect/benefit of early detection.
The latter group had much earlier detection, and their women died sooner and more frequently. It appears our cancer treatment protocols are not well-tuned to early-stage cancers. This, it seems to me, is a significant flaw in the argument for prophylactic screening. (Though isn't the fucked up? "Let's not look as hard for this disease: we kill patients more when we find this one early").