Sunday, November 22, 2009

This is a Test?

This is a Test?

Wow! What a week of reversals in medical testing guidelines for mammography screening and Pap smears.
Let’s sideline the emotional issues for women, who for decades have been inculcated in the necessity and life-saving benefits of annual Pap smears and mammograms. Some women may now feel betrayed for having been put at increased risk by medical science. Other women may feel betrayed, believing the new guidelines represent rationing, thus denying them essential care. They (and their doctors) will hold onto their ingrained beliefs in the old mistaken guidelines.
But, this isn't about feelings or beliefs. This is about science. And sadly, as happens all too often, the science was flawed from the start.
Let’s look at the facts.
The singular and most important reason behind the guideline reversals is the astonishing admission that for decades, and for hundreds of millions of women across the globe, both of these screens done routinely, on an otherwise healthy population of women, does more harm than good.
That is, the new guidelines for Pap smears and mammography are designed to decrease the multitude of subsequent unnecessary diagnostic tests, invasive medical procedures and the psychological damage, physical pain, disfigurement, disability, and deaths associated with them. All, for routine screening that in the best of circumstances, did/does very little to improve a women’s odds of survival, preventing only a small fraction of breast or cervical cancer deaths (an absolute risk reduction of .05%, for breast cancer).
This is not to say that Pap smears and mammograms are of no use. Rather, it is saying that their use as routine screens, for the population at large, damages or destroys far more lives than it saves. This is the inherent danger of ALL broad-based population disease screens.
How can that be, you ask?
Logically, it just makes so much sense that screening will lead to early detection that can lead to early treatment and save lives. And, in some cases it does. Over-screening, to a much larger degree, puts the population at risk of greater harm due to subsequent potentially and outright harmful invasive unnecessary tests and medical procedures.
In performing population screening we have lost sight of context. The “value and meaning of the test is entirely dependent on who we test.” All tests are wrong some of the time. Therefore, testing everyone raises the number of false positives, decreasing the value and meaning of the test. At the same time, it puts that large population of false positives only at increased risk, with no potential benefit.
Not to mention the mindlessness of routine testing and the money such testing and subsequent procedures generate as exemplified in the following: “In addition, Dr. Saslow said, doctors in this country have been performing 15 million Pap tests a year to look for cervical cancer in women who have no cervix, because they have had hysterectomies.
1. “roughly 25% or more of cancers are missed…at least one in four cases of breast cancer is found after a normal mammogram.’”
2. “the cumulative risk of having a false positive mammogram in ten years is least half of all women having mammograms for ten years will receive a positive result that is incorrect…20% of these lead to biopsies.”
3. “the consistency and accuracy in reading mammograms is a serious problem.”
4. “97% of positive mammograms are false rather than true.”
5. “we can estimate that (x-ray exposure from) mammograms cause about seven thousand cases of breast cancer for every ten years of screening.”
6. the psychological toll (ranging from anxiety to depression to suicide) of false positive reporting, while hard to calculate, is huge.
7. In 2001 “the Cochrane Collaboration, a multi-disciplinary group of scientists that produces what are widely believed to be the most respected and objective reviews in medicine, exhaustively examined the data on mammograms. They concluded that mammograms were associated with no improvement in breast cancer death rate, i.e.; that having mammograms was of no benefit at all.” (an absolute risk reduction of .05% when compared to physical breast exam)
As for Pap Smears:
"the argument for changing Pap screening was more compelling than that for cutting back on mammography because there is more potential for harm from the overuse of Pap tests. The reason is that young women are especially prone to develop abnormalities in the cervix that appear to be precancerous, but that will go away if left alone. But when Pap tests find the growths, doctors often remove them, with procedures that can injure the cervix and lead to problems later when a woman becomes pregnant, including premature birth and an increased risk of needing a Caesarean."
As the incidence of most cancer is on the rise, the cry for cure intensifies. However, for decades, focusing only on screening for early detection, treatment and the possibility of cure has not stemmed the growing tide of cancer or cancer deaths. More importantly, it fails to address the causative factors in our environment and our lifestyles that are creating the cancer thus minimizing the environmental and lifestyle changes we can make to dramatically reduce cancer incidence and death rates.
(To read an interesting, opposing viewpoint and my comments on it (pm).)

1 comment:

lee said...

If you were closer (I'm in Boston) I'd give you a big hug. Thank you for, once again, putting yourself on the line, to raise awareness of another very successful fear-driven hard sell. I'm guessing this is a sore and sensitive subject for many and that some women feel totally betrayed. I believe the less we are exposed to radiation of any sort, the better. Don't want to disturb my molecules!

Personally, I tune out in October with all its pink-ribbon subtle and not-so subtle messages. Just learned believe it is November that has become diabetes-awareness month. We even have months now to sell disease! Why not - for starters - a nutrition awareness October, when crops are harvested, instead?