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Another wrinkle to the USPSTF mammogram guidelines kerfuffle: What about African-American women?

A while back I wrote about rethinking how we screen for breast cancer using mammography. Basically, the USPSTF, an independent panel of physicians and health experts that makes nonbinding recommendations for the government on various health issues, reevaluated the evidence for routine screening mammography and concluded that for women at normal risk for breast cancer, mammography before age 50 should not be recommended routinely and should be ordered on an individualized basis, and that routine formalized breast self-examination (BSE) should also not be routinely recommended. In addition, for women over 50, it was recommended that they undergo mammography every other year, rather than every year. These recommendations were based on a review of the literature, including newer studies.

To say that these new recommendations caused a firestorm in the breast cancer world is an understatement. The USPSTF was accused of misogyny; opponents of health care reform leapt on them as evidence that President Obama really is preparing “death panels”; and HHS secretary Kathleen Sebelius couldn’t run away from the guidelines fast enough. Meanwhile, a society I belong to (the American Society of Breast Surgeons) issued a press release accusing the USPSTF of sending us back to the “pre-mammography” days when, presumably women only found breast cancer after it had grown to huge size (just like Europe and Canada, I guess, given that the recommendations for screening there closely mirrors those recommended by the USPSTF). Meanwhile, in the most blatant example of protecting its turf I’ve seen in a very long time, the American College of Radiology went full mental jacket with a press release that was as biased as it was insulting. Meanwhile some physicians even likened the recommendations to going back to being like Africa, Southeast Asia and China as far as breast screening goes in that he actually speculated that he’d now become very busy treating advanced, neglected breast cancers. Unfortunately, as Val pointed out, the communication of the USPSTF guidelines to the public was almost a perfect case study in how not to do it. Even though the science was in general sound and the USPSTF recommendations were in essence close to identical to what other industrialized nations do, they were communicated in just such a way as to produce maximum misunderstanding and misuse for political purposes.

Despite all the hysterical and in some cases disingenuous attacks on the new guidelines, there is one criticism that actually resonates with me because I work at a cancer center in a very urban environment with a large population of African-American women. Last week I heard on NPR this story:

Many African-American women don’t fit the profile of the average American woman who gets breast cancer. For them, putting off the first mammogram until 50 — as recommended by a government task force — could put their life in danger.

“One size doesn’t fit all,” says Lovell Jones, director of the Center for Research on Minority health at Houston’s M.D. Anderson Cancer Center. Jones says the guidelines recently put out by the U.S. Preventive Services Task Force covered a broad segment of American women based on the data available. “Unfortunately,” he says, “the data on African-Americans, Hispanics and to some extent Asian-Americans is limited.”

So while the recommendations may be appropriate for the general population, he says, it could have a deleterious affect on African-American women who appear to have a higher risk of developing very deadly breast cancers at early in life.

And this is actually true. Some of the studies used to develop the latest mammographic guidelines were performed in Scandanavian countries, and in the others arguably African-American women were underrepresented. As the article points out:

When you look at the death statistics for breast cancer in African-American women and compare them to white women, it’s stunning. Beginning in their 20s, into their 50s, black women are twice as likely to die of breast cancer as white women who have breast cancer. In older black women, cases of breast cancer decline, but the high death rates persist.

Overall, breast cancer deaths have been declining for nearly a decade (by 2 percent annually), yet deaths of African-American women have been dropping at a much slower pace. In 2009, an estimated 40,170 women will die from breast cancer. Nearly 6,000 will be African-American women.

Why this disparity exists is unclear. One potential reason is that, for whatever reason, African-American women tend to develop a more aggressive form of breast cancer known as “triple negative” cancer. What triple negative means is that the tumor is estrogen receptor negative [ER(-)], progesterone receptor negative [PR(-)], and HER2/neu negative [HER2/neu(-)]. The lack of estrogen receptor means that these tumors don’t respond to antiestrogen drugs, while the lack of HER2/neu means that they don’t respond to Herceptin. In other words, there are no targeted therapies for these tumors, only cytotoxic chemotherapy or nothing.

More importantly, there is something about the biology of these tumors that makes them more aggressive. They may respond well initially to chemotherapy but they tend to relapse rapidly and kill quickly. This subtype of tumor generally makes up around 15% of cancers among women who are not black, but among African Americans it makes up nearly 40% of tumors. This is a striking difference, and five year survival for women with triple negative cancer is considerably lower than for other types of breast cancer, particularly for young, premenopausal African-American women.

With that background, it’s not unreasonable to ask what “normal” risk for breast cancer is for purposes of recommending a program of screening mammography. On the one hand, if young African-American women are at a higher risk for breast cancer, then beginning their screening at an earlier age makes sense because it is the lower risk of breast cancer in women in their 40s that led the USPSTF to conclude that the risk-benefit ratio of mammography was less favorable in this age range. On the other hand, the more aggressive nature of breast cancer in young, premenopausal African-American women means that length bias becomes a consideration. Basically, length bias means that mammographic screening tends preferentially to pick up slower-growing, more indolent tumors. Faster-growing, more aggressive tumors tend to “pop up” between screening intervals. So, even if screening were started earlier for African-American women, it’s not clear that the benefits would be as dramatic as we might hope. Indeed, the NPR story alludes to this:

Sheppard even wonders if the old guideline of routine screening every year beginning at age 40 is good enough. “The tumors are growing fast and the intervals that we prescribe may not work,” she says. “How can we have better diagnostic tools, better screening tools that can capture the women that aren’t the average woman?”

A blogger going by the pseudonym of Isis the Scientist brought up this very issue the other day has a point when she wonders:

The other thing I wonder about is the effect these recommendations will have on the perception of health care equity. A black woman is more likely to develop aggressive cancer than a white woman before age 50, yet the USPSTF has recommended not to actively screen women less than. I wonder how this will be interpreted by that community? Black women experience a distrust of scientists performing clinical trials (second reference here), operate within a healthcare that is not always sensitive to their needs, and use mammography as a resource less frequently than white women. Will these new recommendations foster feelings of distrust and reinforce the notion that the current health care system does not adequately meet their needs?

There is a legitimate concern that the USPSTF guidelines may not be a good fit to African-American women because not only do they tend to have more aggressive disease at a younger age but they have been underrepresented in many of the large screening trials that have been used to formulate the recommended mammography guidelines. For that reason, upon further reflection I don’t think that the USPSTF guidelines should be used to determine how and when African-American women should undergo screening, as I consider them to be at a high enough risk that screening beginning at 40 makes sense.

However, as much as she did raise a valid point when she questioned whether the current mammography guidelines should apply to African-American women, still I must remonstrate with Isis and point out that the article by Nicholas Kristof that she cited in support of her speculations is dubious at best and a load of grade-A woo at worst. For example, Kristof states:

Dr. Philip Landrigan, the chairman of the department of preventive medicine at Mount Sinai, said that the risk that a 50-year-old white woman will develop breast cancer has soared to 12 percent today, from 1 percent in 1975. (Some of that is probably a result of better detection.)

What’s very important to realize is that 12% of women do not get invasive breast cancer as compared to 1% in the past. Moreover, “some of that” is not “probably” a result of better detection. Most of it is almost certainly a result of better detection of earlier breast cancer, including pre-invasive lesions like ductal carcinoma in situ (DCIS), through widespread mammography screening programs. Indeed, as this report by the American Cancer Society shows, the incidence of invasive breast cancer per 100,000 women is not increasing nearly that fast. In fact, it’s not increasing at all. On the contrary, since 2002 breast cancer incidence has actually declined, very likely due to the massive decrease in hormone replacement therapy use in the wake of the 2002 report from the Women’s Health Initiative showing that HRT doesn’t decrease cardiovascular risk but does increase the risk of breast cancer. Figure 1 in particular shows this trend, while Figure 2 shows what’s really driving the apparent increase in breast cancer diagnoses, a massive increase in the incidence of preinvasive DCIS.

We’ve known for quite some time that what’s driving this increase is nearly all mammographic screening; indeed, the article speculates that we may have finally reached the plateau in the increase of DCIS cases with the widespread use of mammographic screening over the last 20 years. That 12% figure is not just invasive cancer; it includes DCIS. While invasive cancer diagnoses are more or less stable, diagnoses of DCIS skyrocketed due to mammography. Indeed, this dovetails nicely with my earlier discussions of overdiagnosis due to mammography, because this is exactly what I’m talking about. Mammography picks up early cancers that may or may not ever threaten the life of the woman; that’s what overdiagnosis is. Moreover, overdiagnosis leads to overtreatment, as we don’t have a good handle on what percentage of DCIS lesions progress to life-threatening breast cancers if left alone. So we treat them all with surgery, nearly all of them with radiation, and most of them with Tamoxifen after surgery and radiation.

Unfortunately, in the article Kristof takes a somewhat reasonable suspicion and runs right off the dock with it into woo land, and Isis appears not to have been skeptical enough about his claims, given that she then used Kristof’s article as the basis for speculation that maybe African-American women, tending to be of lower socioeconomic status than Caucasian women, are exposed to more toxic chemicals and endocrine disruptors. Unfortunately, as Peter Lipson characterized his article, Kristof has clearly fallen for the “one true cause” fallacy so beloved of practitioners of woo, labeling endocrine disruptors such as BPA as a major environmental cause of the apparent increase in breast cancer diagnoses. Don’t get me wrong, there may well be something there in that BPA and endocrine disruptors may contribute to breast cancer, but almost certainly not to the extent that Kristof claims, even given the evidence he cites.

In addition, if there’s one thing about breast cancer, it’s that no single environmental exposure has been found to be strongly correlated with it; most of the correlations other than family history and exposure to hormone replacement therapy, including both positive and negative correlations, have been in general pretty weak. Indeed, I was recently peripherally involved in an effort to design a project to study environmental influences in breast cancer, and there are amazingly few validated environmental factors that increase the risk of breast cancer. Also, timing is very important; it may well be that it is exposure to these factors in adolescence or childhood in a “window” of susceptibility, not in adulthood, which is when they are normally studied. Right now, that’s where the current research efforts seem to be focused. In addition, breast density, which is primarily genetically determined, is a known risk factor for breast cancer as well, and investigators are actually planning to study that at our institution. All in all, it’s a hideously complicated business combining genetic and environmental factors that I am only beginning to wrap my brain around, while Kristof’s article was simplistic and alarmist in the extreme. For better information, I recommend a report from the Endocrine Society for the more sober, balanced perspective, and a report from the Breast Cancer Fund for arguments more explicitly in favor of a link. More information, including the chemical industry’s viewpoint (if you’re interested), can be found here.

I firmly believe that the recommendations for how we screen for breast cancer were overdue for an overhaul. Badly. However, the USPSTF guidelines may have gone too far too fast, at least for public consumption in light of the years of urging by the government and private advocacy organizations for all women over 40 to be screened, recommendations that say that mammography before age 50 may not be particularly beneficial were a hard pill to swallow. As I think about it more, though, one big flaw in the guidelines is that there was little consideration of how changing screening recommendations would impact special populations that may be at higher risk, such young African-American women. Worst of all, the USPSTF recommendations are an example of some of the astoundingly worst science communication I’ve seen in a long time. No groundwork was laid to prepare the public; the guidelines were just announced; and the spokespeople for the USPSTF looked like deer in the headlights when they showed up in the media to defend the guidelines. Specialty groups protecting their interests such as the American Radiologial Society and its President Dr. Kopans ate them for lunch and then laughed at their discomfiture. Meanwhile high ranking government officials couldn’t distance themselves fast enough, and lawmakers and ideologues had a field day playing politics with the guidelines.

In the end, while I still think that the new guidelines are reasonable for most non-black women, after thinking about it I doubt that they should be applied to African Americans. Finally, I’m now convinced more than ever that screening will only have limited effects in decreasing mortality from breast cancer, regardless of the test used, as long as we have so poor an understanding of the aspects of breast cancer biology that govern which early cancerous lesions will progress, which will not, and which will regress. Until we do, if there were developed a test to replace mammography, the same problems of overdiagnosis and overtreatment would remain. More than ever, we need to develop an understanding of the biology of breast cancer sufficiently advanced that it permits us to develop imaging tools and biological markers that can differentiate breast cancers that will progress and those that are not going to threaten the life of the woman. At the very least we need better indicators of risk. Until we have these things, screening will remain a highly imperfect tool that doesn’t save as many lives as it has the potential to.

ADDITIONAL READING ON MAMMOGRAPHY, BREAST CANCER, AND CANCER SCREENING:

  1. The early detection of cancer and improved survival: More complicated than most people think
  2. Early detection of cancer, part 2: Breast cancer and MRI
  3. Do over one in five breast cancers detected by mammography alone really spontaneously regress?
  4. PSA – To Screen or Not to Screen
  5. Are one in three breast cancers really overdiagnosed and overtreated?
  6. The cancer screening kerfuffle erupts again: “Rethinking” screening for breast and prostate cancer
  7. The USPSTF recommendations for breast cancer screening: Not the final word
  8. The Mammogram Post-Mortem

Posted in: Cancer, Clinical Trials, Diagnostic tests & procedures, Public Health

Leave a Comment (14) ↓

14 thoughts on “Another wrinkle to the USPSTF mammogram guidelines kerfuffle: What about African-American women?

  1. Harriet Hall says:

    I don’t see a problem. The recommendations were for the general population at average risk. If race is a risk factor, that just adds into the equation of increased risk that constitutes an indication for earlier screening for an individual.

  2. edgar says:

    I hope the sister study results will shed light on some of these exposure issues.

  3. windriven says:

    I’d like to offer a couple of observations:

    1. This argues that mammography schedules are best determined by the woman and her physician based on her specific risks;

    2. While widespread mammography may have led to ‘overdiagnosis’, especially of DCIS, one ultimate result is likely to be a much deeper understanding of DCIS, its progression and various factors that influence prognosis. Women in general are likely to benefit from this;

    3. I take exception to Dr. Gorski’s broad statement that “opponents of health care reform leapt on them as evidence that President Obama really is preparing “death panels”.”

    I don’t believe that there are very many “opponents of health care reform.” Rather, there seems to be almost universal agreement that the current system is grossly inefficient and badly in need of reform. There are a good number of people who are wary of the current bills coursing through the House and Senate.

    It is unfair and inaccurate to lump thoughtful skeptics with those who would demagogue the issue.

  4. Basiorana says:

    windriven, while the majority of those concerned about the current bills want reform, there are many people who do genuinely simply oppose healthcare reform all together. They mask it as concern about the issues, but they actually don’t want reform. These people are called “people who work for insurance companies.” My mom’s one of them, she’s petrified that any government involvement in the issue at all will make her company freak out and start paring down non-essential costs, including her branch. She, her company, and most of her co-workers agree that any healthcare reform would be bad for them and adamantly oppose it– and yes, they are happy to use the death panels arguments, among others, if it might save them from losing their jobs in this economy.

  5. windriven says:

    Basiorana,
    Reforming health care does not demand a role for the government as an insurer. In fact from my perspective the specter of a “single payer” system has been an unusually destructive fantasy of the polar fringes. The far left sees it as an Utopian panacea and the far right sees it as the shackles of socialism.

    Healthcare reform is a remarkably complex issue. Our elected representatives have chosen to mount a sweeping reform based, so far as I can see, on little more than wishful thinking and political cant. Their historical record in ‘sweeping reform’ does not inspire confidence in this effort. Better I would argue, that they approached reform methodically, piece by piece.

    Healthcare cost as a percentage of GDP is arguably too high. But demonizing big pharma, for instance, isn’t going to reduce that cost. OECD figures from 2003 show that in the US pharmaceuticals consume only 12.9% of total health care expenditures – rather less than the 17.7% spent on average (though one most also factor in that the US total expenditures on health care per person are also higher).

    It is also true that a substantial portion of Americans are uninsured. Some of these are people who desperately want and need insurance. But some are young people and others who chose to forgo health insurance and save the money for a down payment for a house (or spend it on drugs, sex and rock ‘n roll). If all of these people are brought immediately into the system, where are the primary care physicians to care for them going to come from? One does not simply open a tap and have bright new MDs flow out. It takes a dozen years. And how are these new MDs to be enticed into family practice or internal medicine?

    An old aphorism holds that everybody wants to go to heaven but nobody wants to die. It is easy for people to argue against heroic measures and costly therapies. Until it is their mother who is dying. As Josef Stalin noted: one death is a tragedy, a million deaths is just a statistic.

    Their needs to be a serious national dialogue about the breadth of health care that we want, the health care that we can afford and the health care that we are willing to buy for those who can’t pay for their own. Unfortunately, these are complex issues fraught with emotion and requiring difficult choices.

    It is so much easier to shriek ‘death panel’ or to chant ‘free health care for everyone’ than to address these issues head on.

  6. cruzrad says:

    I am similarly disappointed by the sensationalized press release offered by my professional organization, the American College of Radiology, linked above in Dr. Gorski’s post.

    There is however, some truth behind the unfortunate hyperbole. Of course there will be some number of women in their forties who will die from breast cancer if not screened. Screening mammography picks up tumors at an earlier stage than would otherwise be the case. Consider a patient in her forties with a small, one centimeter invasive cancer. If the tumor happened to be located superficially (close to the skin), it might be easily palpable and found by the patient or by clinical breast examination. The chance that a lesion that size had metastasized already would be small and the patient would be expected to do well with therapy. However, if that same lesion was located deep in the breast, particularly in a large breast or one with tissue that feels “dense” and thereby less accessible to physical exam, it might grow to two or three centimeters before it’s noticed, with a much greater chance of metastatic spread. Mammography affords the ability to find those small lesions, deep in the breast tissue. Given the current state of knowledge and the difficulty predicting the natural history of small early tumors, concerns regarding overdiagnoisis and overtreatment are appropriate, especially with regards to DCIS (preinvasive cancer). But the fact remains, opportunities to diagnose some invasive cancers at an early stage will be compromised. There will be fewer found in younger women in their forties because of a lower incidence compared to the older age groups, but a significant number none the less. The acceptable cost/benefit ratio varies depending on who’s doing the analysis. It’s true that most European countries have screening guidelines more similar to the USPFST recommendations, a decision perhaps largely related to resource allocation? Some countries offer only a single view screening mammogram, a practice clearly designed to save costs at the expense of completeness.

    Regarding the widely discussed harms associated with “unnecessary biopsies”, while naturally the whole process is anxiety provoking, benign results are always met with a sense of relief. I think it fallacious to define a procedure with benign results as being, by definition, unnecessary and/or harmful. Our imaging tools do not have 100% specificity in all cases, though in many there is a very high degree of certainty with regards to the benign or malignant nature of a lesion. There is an overlapping spectrum of imaging findings however, and many lesions are indeterminate. If a biopsy reveals a malignancy then the biopsy was necessary and helpful, and if benign, unnecessary and harmful? It depends on the probability of cancer being present. When a radiologist recommends a biopsy, probabilities are discussed. The patient is an active participant in the process. If the lesion in question is highly suggestive of a malignancy (BIRADS 5), this would be conveyed to the patient. If there is more uncertainty (BIRADS 4), rough estimates of the chance of cancer are discussed. Sometimes followup imaging to document stability is sufficient (BIRADS 3). There has been considerable improvement in imaging sensitivity and specificity, but it’s a long way from being perfect.

    It should also be understood that it is a relatively rare occurrence these days that a patient need go to surgery for tissue diagnosis. The number of benign surgical biopsies performed has dramatically dropped the last two decades after radiologists developed techniques for image guided needle biopsies, e.g. stereotactic (mammography driven) and ultrasound and MRI guided biopsies. The vast majority of needle biopsies, which are typically 10-20 minute outpatient procedures, are very well tolerated with a very low complication rate. The accuracy, in experienced hands, is equivalent to surgical biopsies.

    For those interested in an excellent summary of mammography and the studies supporting screening guidelines, in FAQ format, prepared by the American College of Radiology and the Society of Breast Imaging…..

    FAQ’s about Mammography and the USPSTF Recommendations

  7. Harriet Hall says:

    cruzrad,

    Do you have any statistics on how many patients who have needle biopsies go on to require surgical biopsies? In my case it was 2 for 2: twice, the results of the needle bx were inconclusive and I ended up getting a surgical biopsy. Maybe I’m just unlucky. :-)

    I must say the stereotactic biopsy procedure was an interesting one, as was the localization wire insertion prior to the surgical biopsies. They sure took a lot of x-rays during those procedures!

  8. cruzrad says:

    Dr. Hall,

    There are three circumstances which would require a surgical biopsy (excisional biopsy) or lumpectomy (term usually reserved for resection of malignant tissue) after a needle biopsy. If the needle biopsy revealed cancer, the patient would be referred for a lumpectomy, with or without lymph node resection depending on whether the malignancy was invasive or DCIS. Doing a needle biopsy first, even in those cases where the diagnosis is near certain based on imaging alone (BIRADS 5), allows both procedures (lumpectomy and lymph nodes) to be performed at the same time (one trip to the OR instead of two). In addition, it is helpful in surgical planning to have a definitive diagnosis in advance. The rate of positive surgical margins, indicating incomplete resection, are fewer in women who are diagnosed preoperatively with a needle biopsy. The second reason surgery would be needed is if the needle biopsy showed one of the non-cancerous but high risk lesions that can be associated with malignancy, including atypical ductal hyperplasia, radial scar, papilloma and a few others. The incidence of histology upgrade to malignancy following surgical excision of these lesions is reportedly 10-20%, although it is significantly lower in my own experience. The third reason would be discordance between the imaging findings and the needle biopsy results. This is very uncommon (in my experience). So when you say your needle biopsy results were inconclusive, you might have had one of the high-risk lesions requiring more tissue to analyze or perhaps the results were discordant. So yes, I would say you were unlucky!.

    Regarding your question on statistics, a desirable positive predictive value of a needle biopsy (percentage of positive biopsies) is considered to be between 25-40%. It’s a guideline, but in practical terms, if it’s too low, your threshold for recommending a biopsy may need adjusting. If it’s too high, there may be concern you’re missing some significant pathology. The number varies depending on experience, and perhaps on the number of times you’ve been sued. The reality is breast imaging is one of the more litigiously active specialities in medicine.

    The digital images used for localization during a stereotactic biopsy are very low dose with a small field of view. On average five or six are required, followed by a two view mammogram to document positioning of a small metallic clip deployed at the biopsy site to aid in future localization if surgery is required. The clips are now sonolucent (visible with ultrasound) and can therefore be placed with ultrasound guidance, reducing the number of mammograms required. This has made wire localization much quicker and more accurate (procedure where a hooked wire is inserted by a radiologist to localize non-palpable resection targets for the surgeon who then removes the tissue surrounding the end of the wire). This is also followed by a two view mammogram to show the relationship between the inserted wire and the target lesion.

  9. David Gorski says:

    It should also be understood that it is a relatively rare occurrence these days that a patient need go to surgery for tissue diagnosis. The number of benign surgical biopsies performed has dramatically dropped the last two decades after radiologists developed techniques for image guided needle biopsies, e.g. stereotactic (mammography driven) and ultrasound and MRI guided biopsies. The vast majority of needle biopsies, which are typically 10-20 minute outpatient procedures, are very well tolerated with a very low complication rate. The accuracy, in experienced hands, is equivalent to surgical biopsies.

    No one has said otherwise. However, one notes that you failed to mention the issue of overdiagnosis leading to overtreatment, which a recent study has suggested may be as high as 1 in 3 mammographically detected lesions. That’s the real harm of too intensive screening, subjecting women whose cancer would never have threatened their lives to surgery, radiation, and chemotherapy. Moreover, there is no good evidence that mammographic screening has any effect on all-cause mortality in women age 40-49. One can certainly debate whether it’s worth the cost to screen women between 40-49. I still tend to recommend it, just not as strongly as I used to and not every year in women who don’t have any special risk factors or family history. In other words, in response to new data, I’ve become a bit less dogmatic and individualized in my recommendations for women between the ages of 40-49.

    In any case, I stand by my criticism of the ACR’s hyperbolic response to the USPSTF’s guidelines. Such an exaggerated response comes across far more as turf protection than actual engagement and debate over the science. In fact, if anything, what I said in my post above is much milder than what I really think about the response of radiology societies to the USPSTF guidelines. That includes the Radiological Society of North America at its meeting a couple of weeks ago.

  10. cruzrad says:

    To clarify third sentence in the last paragraph above…… The clips are sonolucent and localizing wires can therefore be placed with ultrasound guidance, reducing the number of procedure related mammograms required.

  11. JMB says:

    I left a more windy dissertation on this subject in your other post about the USPSTF recommendations. In short form, be careful about what science based medicine is. If it is to be science based, it should be devoid of value judgments. A scientist making a value judgment is not making a scientific observation just because they are a scientist. The most effective screening strategy may be derived from scientific observations. The most effective screening strategy is that which maximizes the number of lives saved. That strategy is determined from the results of the large randomized clinical trials, and computer models based on Bayes theorem or stochastic simulations. To recommend the most efficient strategy, you must introduce a utility function incorporating a value judgment. The USPSTF placed a value on minimizing number of exams, and based their recommendations on when the plot of years of life saved versus number of examinations performed levels out. The efficient frontier analysis they performed comes from Modern Portfolio Theory in economics. The USPSTF stated in other recommendations that efficient frontier analysis plotting lives saved versus number of exams mirrors cost-effectiveness analysis.

    The most effective screening strategy is science based (annual mammography from age 40 to 79). The most efficient screening strategy includes a value judgment, and is not science based (biennial mammography from age 50 to 75). No science would allow the statement that saving 1 in 1330 lives is recommended, but saving 1 in 1904 lives is not recommended. That is a value judgment, even if it is made by scientists. The use of a value judgment is why the USPSTF recommendations were criticized by the ACR, ACS, an ACOG.

    I suspect that if you utilize statistics on the prevalence of breast cancer by race, you would calculate a figure closer to the 1 in 1330 lives of African-American women deemed efficient by the USPSTF. Of course, since breast cancers in African-American women tend to be more aggressive, you might find that number raised back to the 1 in 1900 level (the 1 in 1900 is based on the percentage of breast tumors we can detect early, as well as the success of therapy). I would still recommend yearly screening to all women between age 40 and 50. Now whether an insurance company or medicare would agree to make an exception based on race is another question.

    State programs to provide financial assistance to uninsured women for breast cancer screening have, in some states, already adopted the USPSTF guidelines. If that continues, there will be a measurable increase in breast cancer mortality in those African-American women (and white women) who depend on state assistance within 10 years. Whether it will be statistically significant depends on the number who receive state assistance.

    If a cancer grows faster, then the screening intervals need to be shorter in order to produce the desired effect. One of the problems in many of the randomized clinical trials is that in most, women between 40 and 50 received on average 3 to 4 exams over a period of ten years. In the Canadian Breast Cancer Screening Trial, many received a single view xerogram for the screen. 3 % refused any screening mammogram, but were still included in the ‘invited for screening mammography’ group. Still, the meta-analysis performed by the USPSTF predicts a 15% reduction in breast cancer mortality if women are screened between age 40 and 50.

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