Prostate Screening and the Public’s Health

For the first time in several years, I am writing about prostate cancer screening. I had hoped that this was sufficiently covered in 2009, with PSA Screening: What is the value? (March 21) and the excellent guest piece by Robert Ferrer, PSA Screening: “One of Medicine's Great Success Stories"? (October 27), and finally a bit of celebration in 2011 with PSA redux: The USPSTF finally recommends NOT getting it! (October 14). However, like the proverbial bad penny (or to use a more au courant analogy, zombie), this issue continues to return from the dead. The most recent effort is “Bring Back Prostate Screening”, a NY Times op-ed piece by Deepak A. Kapoor on July 6, 2015.

What Dr. Kapoor is suggesting is obvious from the title, but the question is “is there some new information, some new research, that now makes such screening more reasonable or appropriate?" The answer, unfortunately (because it makes more work for the zombie hunters) is “no”. Dr. Kapoor suggests that there is. He notes research is this field is “... now paying off.” He says that the decision to recommend against prostate screening by the US Preventive Services Task Force “…didn’t take into account adaptations that urologists have made to help better identify patients likely to develop deadly prostate cancers.” He cites the increased sensitivity of PSA screening, the individualization of it to the risks of different men, and the use of PSA trajectory (its rate of increase, or not), as well as new methods of assessing cancer like MRI. However, his assertion is incorrect; all of this information was available to the USPSTF when it made its recommendations, and was taken into account. It is not new.

“At the time,” Dr. Kapoor notes, “I and many other urologists warned of public health repercussions. Our fears have materialized. Since 2010, fewer biopsies have been performed and fewer prostate cancers found. But studies show an increase in the risk that a cancer, when found, will be more aggressive.” This sounds scary, but it is to be expected; when you stop screening everyone you won’t find the cancers early. A big part of recommending against PSA screening was that so many of the cancers it identified were indolent and not going anywhere; the aggressive cancers will be the ones that eventually show up. Indeed, he actually acknowledges that “No increase in cancer mortality has been observed,” but continues to raise the alarm with “…that may be a matter of time; aggressive cancers are less treatable.” So maybe we should be scared.

Well, in fact all prostate cancer is treatable. All cancer is; in fact all conditions are. The question is how effective is the treatment? Does it cure? Does it prolong life? Does it improve the quality of remaining life? This is the area that Dr. Kapoor and his colleagues do not address, because, for prostate cancer, the answer is basically no. If you have the more common kind of prostate cancer, it is slow-growing (indolent) and may even disappear itself; you will die with it, rather than from it. If you have the less-common aggressive form, you may well die from it, and unpleasantly; prostate cancer metastases go to bone and cause a lot of pain. Sadly, however, treatment does not seem to impact this. The “cures” from treatment of prostate cancer are of the ones that would have “cured” themselves, or at least not have manifested with symptoms. The mortality from aggressive deadly cancers is not changed by treatment. This is the critical point that discussions of the sensitivity and specificity of PSA or any other kind of screening often ignores. Not only can they not reliably distinguish between the indolent and aggressive types of cancer well, even if they could and we had a test to reliably tell which one you had, it is only of importance if treatment can make a difference. And in terms of mortality, it doesn’t. What about the other results from treatment? Improved quality of life? Well, here even Dr. Kapoor notes that “cancer treatment can reduce quality of life.” If you consider impotence, urinary incontinence, and the many unpleasant and painful effects of radiation on the rectum to lower quality of life, you betcha.

We can dismiss Dr. Kapoor’s comments by saying he is a urologist, and they make their money treating prostate cancer; can you imagine the impact on their income if we didn’t treat it? But this misses the far bigger issue, which is that we are enamored with – and, more important, spend huge amounts of money on-- high-technology interventions rather than the prosaic, low-tech interventions that have actually been demonstrated to improve the public’s health. Screening for prostate cancer, and overuse and reliance on mammographic screening for breast cancer, are huge industries which (even in breast cancer) have had relatively little impact on mortality. Providing good prenatal care and preventing unwanted pregnancy, ensuring treatment of common diseases like hypertension and diabetes, ensuring that children are not only immunized against infectious disease but are well-fed, well-housed, and well-educated, and free from poisoning by environmental toxins (including bullets) – the basic components of public health and primary care -- may seem less sexy and stimulate our collective psyches less, but they are the things that actually increase population health.

One of the newer fascinations is genomics, the identification of each person’s sequence of DNA. The promise of “precision medicine” is that we will find out who has the risk gene for which disease, and treat it directly and appropriately; treatment for cancer will be based on the genes you have just as treatment for bacterial infections is based on the organism identified by culturing it in a microbiology laboratory. It is so exciting! It is so “sci-fi today”! The American Board of Family Medicine, for example, is planning to create a new self-assessment module (“SAM”, tests that family doctors have to complete one of each year to maintain their Board certification) on genomics. On the other hand, it doesn’t think we need one on contraception, which is too small an area (isn’t it just part of “women’s health”? Oh, do men have a role in contraception also?), unlike genomics, which could affect EVERYTHING!

Except, so far, it hasn’t and there is little evidence to suggest that it will anytime soon. I wrote a blog on the topic on February 1, 2015 (“Precision medicine, trade policy and the cost of drugs: benefiting people or profit for business?) after the appearance of a Times op-ed by Mayo Clinic cancer expert Michael Joyner (“’Moonshot’ medicine will let us down”, January 15, 2015); Dr. Joyner has more recently contributed more comprehensive articles on the topic to JAMA (“Seven questions for personalized medicine[1]) and The Lancet (“Is precision medicine the route to a healthy world?”[2]) in which he makes the important point that most disease is not the result of a single gene, but rather the result of a complex interplay of different genes and the environment. Indeed, the only cancer-specific genes that have been identified so far are the breast cancer genes BRCA1 and BRCA2, and no treatment has emerged; we simply say “get mammograms more often and consider prophylactic mastectomy”.

Spending all this money on precision medicine, on high-tech interventions, expensive drugs and devices is like blowing your house budget on art for the walls before you have built it. Some art is great, some is mediocre, and some is poor, but none will hang well on a jerry-rigged house made poorly of shoddy materials because there was no money left. Some high-tech, expensive interventions are worthwhile but what we really need to increase the population’s health is public health nurses making home visits to pregnant and recently delivered women, and their children; public health nurses or community health workers or even doctors making visits to people’s homes to assess the real risk factors to their health and reasons that they might not be able to comply with treatment plans. We need more primary care, not more interventionalists. But most important, we need to apply what we know works, what we know how to do, to everyone.

That is how we move the needle on population health.

---

[1] Joyner MJ, Paneth N, Seven Questions for Personalized Medicine, JAMA. 2015 Jun 22. doi: 10.1001/jama.2015.7725. [Epub ahead of print]

[2] Coote, John H, Joyner, Michael J. Is precision medicine the route to a healthy world?. The Lancet385.9978 (Apr 25, 2015): 1617.

Medical testing: is it about quality?

In her New York Times “Well” blog of April 13, 2015, physician Abigail Zuger comments upon “Quantifying Tests, Instead of Good Care”. She discusses a variety of factors that lead to physicians ordering more and more tests. In part, this is the simply the result of the advance of technology and thus the profusion of tests that can be done --  laboratory tests, imaging (like x-rays and their ever more complex cousins), and even parts of the physical examination (“Yes, little blood pressure cuff over there in the corner, that means you”) --  which sometimes can be seen as meaning they should be done. Other factors are about money. The tests cost money, a negative for patients and insurers, but they make money for the laboratories and imaging facilities and the hospitals which often own them, and frequently employ the physicians doing the ordering. Dr. Zuger notes that “Ordering tests, chasing down and interpreting results, and dealing with the endless cycle of repeat testing to confirm and clarify problems absorb pretty much all our time.”

Another impetus is our desire – patients and physicians alike – to find out what is wrong when there is something wrong. Or, when there is nothing really wrong, to perhaps prevent later disease by finding something hidden lurking inside. There are all these tests we can get! The patient may have had many of them before, ordered by another provider, or know people who have had them. They hope that something will give them an answer. The doctor may feel that there may be an answer out there that s/he might miss if a test is not ordered, or if s/he is a primary care physician that a specialist might order these tests so maybe we should do it first; after all, it sometimes seems as if one thing specialists do when we refer patients to them is order a bunch of tests that we could have. Or, and this is a big focus of Dr. Zuger, that their “quality ratings” may suffer if s/he doesn’t order these tests.

Quality ratings are measures of things that doctors should do (or, sometimes but more rarely, should not do) for patients with certain conditions or complaints; increasingly, insurers, employers, and third-party groups are assessing the quality of care that a physician delivers in this way. Are these recommendations not based on evidence? In many cases, they are. For prevention, the US Preventive Services Task Force assesses the degree to which tests may be indicated or not for different people, often based upon their age and sex. It gives them ratings: ‘A’ is strongly recommended based on good evidence, ‘B’ means there is some, but weaker, evidence to support doing it, ’C’ means there is conflicting evidence and patient preference should be taken into account, ‘D’ means not recommended (might even be harmful), and ‘I’ means insufficient evidence to assess. A smart phone app, ePSS, can be downloaded by anyone; put in age and sex and it tells you which preventive tests are recommended.

Of course, not all doctors do all the recommended screening tests, and frequently they do tests that are not recommended (e.g., PSA to screen for prostate cancer) or more frequently than recommended (Pap smears to screen for cervical cancer), or in people for whom the test is not recommended (mammograms in younger women). When it comes to diagnostic testing rather than screening, looking for the cause of something when the patient is actually ill, there is even less consensus, and often a prevailing attitude of “more (testing) is better”. One effort to combat this is the Choosing Wisely campaign begun by the American Board of Internal Medicine Foundation. This campaign asked specialty societies to identify 5 or more commonly-done tests or interventions in their specialty that should not be done. However, the same recommendations are not always endorsed by every relevant organization. For example, the American Academy of Family Physicians recommends “Don’t do imaging for low back pain within the first six weeks, unless red flags are present.” Great, but neither the American College of Radiology nor the American Academy of Orthopaedic Surgeons, arguably the groups that could make money from this, has such a recommendation.

And then there is the risk. Some of the tests receiving USPSTF ‘D’ recommendations are more than not helpful; they can lead to harm, and this is even more true of the many potential tests that can be done looking for disease. Discussing the work of a collaboration at the Dartmouth Medical School that looks at the utility of tests, Dr. Zuger notes that such iconic treatments as controlling blood pressure can lead to bad outcomes in many older people where the benefits (avoiding stroke and other complications) begin to be outweighed by the risks:  “One study found that nursing home residents taking two or more effective blood pressure drugs did remarkably badly, with death rates more than twice that of their peers. In another, dementia patients taking blood pressure medication with optimal results nonetheless deteriorated mentally considerably faster. Yet no quality control system that I know of gives a doctor an approving pat on the head for taking a fragile older patient off meds.”

This is just the tip of the iceberg. Tests cost money, and often show results that lead to more tests, and then maybe to procedures (biopsies, for example) that maybe show abnormalities that lead to bigger interventions. And, sometimes these interventions are life-saving, but not always. Or maybe, even, not often.  And they do often have side effects, some of which are not insignificant. The person in whom a series of tests identifies cancer and is then treated and then survives is almost always grateful for the testing and the treatment, although in many cases they would have survived just the same with no treatment, and without the costs both in dollars and in side effects. The classic example is prostate cancer, where the evidence of any treatment making a difference in survival is weak at best; it is either a devastating disease from which one dies, painfully, or more commonly a benign condition that one dies with but not from but which treatment seems to have little influence on. Except for the cost, and the non-trivial side effects of impotence, incontinence, and the effects of radiation on the rectum.

Increasingly, data is showing that much breast cancer is similar. As discussed in my December 2012 blog post “More on mammography: just because you don't like the results doesn't make research junk science”, a large study by Bleyer and Welch showed that, with new and more sensitive mammographic screening, many more women are being diagnosed with early-stage breast cancer. However, despite treatment, we are not seeing anything like that reduction in late-stage breast cancer, which means most of those early stage cancers would not have progressed at all. And yet every woman diagnosed and treated sees herself as a survivor who has been cured, even in those cases where progression would not have occurred. In his wonderful recent New Yorker article “Overkill” (May 11, 2015), Atul Gawande notes that we treat all “cancer” as if it were rabbits in a pen who have to be chased down before they escape, when in fact many cancers are “birds” that have flown away and are gone before we can do anything and many others are “turtles” who are not going anywhere whatever we do.

The goal of medical care is now to achieve the “Triple Aim” of high quality, patient satisfaction, and lower cost. As with many things that come in threes, it is not that hard to achieve two but very challenging to achieve all three. Patients satisfaction is important, but not at any cost. Cost control is good, but not if it seriously limits quality. One place to start, then, is with quality, and specifically not doing what is useless or even harmful as assertively as we do what is likely to be of value.

And, of course, to make sure that it is the disease or risk of disease that determines what tests are done, not people’s insurance or socioeconomic status, ethnicity, gender or personality.

Guidelines, bias, and your health

One of the challenges in educating health-care professionals is the massive – and growing -- amount of information about diseases, diagnosis, and especially treatments that are available. This is not only an issue for students and residents, but for continuing education; if a doctor or nurse or pharmacist knows only what they learned in school, it will be outdated in a very few years. Thus, the health professions have committed to the concept of “life-long learning”, but how this happens, and how effective and accurate it is, is the challenge.

With the development of the Internet, information is extraordinarily widely shared very quickly. It makes information available not only to health professionals, but to everyone; in the “old days”, perhaps someone with symptoms, or a new diagnosis, might go to the library, or find an outdated copy of Morris Fishbein’s “Handy Home Medical Encyclopedia” or a similar book. Now they go to the internet and are overwhelmed with information. The problem is that this information may be correct, partially correct, or wrong; it may be complete, incomplete, or valueless. There is a difference between information and truth, and certainly between information and wisdom. Wisdom, and truth, require information, but much  of the information is chaff or worse.

If keeping up with information and sifting through it to discover what is true, relevant, and important is hard for a person who wants to find out about their one condition, it is truly daunting for health professionals who need to keep up on many. There are so many drugs! And new ones all the time! And they are all better, improved, more effective (and certainly more expensive!) than the old ones. Until, of course, we find out that they are not. Or, worse, dangerous. Sometimes so dangerous that they have to be pulled from the market.

In his Op-Ed piece in the New York Times on June 12, 2013, “Healing the overwhelmed physician”, Dr. Jerry Avorn of Harvard Medical School calls this the “Stendhal syndrome”, after the French author who, on an 1817 visit to Florence, “…was seized by palpitations, dizziness and a feeling of being overwhelmed by the abundance of great art surrounding him”; the over-abundance of information, too much to grasp, integrate, and categorize, not to mention utilize effectively.  How can doctors and other health professionals get through this to “truth”? To be able to most effectively help, and, primum non nocere,  not hurt you?

One traditional method, adopted by our friends in the drug industry, has been “detailing”. Pharmaceutical representatives (called, regardless of gender, “detailmen”) fanned out, visiting physicians, giving out free samples of their wares as well as food and pens and sticky-note pads and clocks and calendars and little scale models of whatever organ their drug worked on, along with information about the drug. The information might have been accurate and complete, but often was skewed, and almost always was research funded by the manufacturer. The detailpersons were easily identifiable, even when not pushing a cart full of pizza for “grand rounds” because they were all good-looking and so much more well-dressed than run of the mill health care workers. What a great system! You get information about new drugs, direct from the person selling them, and little scale models of the urinary system and donuts too! Isn’t that how we all hoped our doctors were keeping up with the field of caring for our health?

Well, ethics rules have limited the ubiquity of detailpersons, and free gifts, and even samples; the “educational cruises” to the Caribbean just for being a high-utilizer of a company’s drugs are all but gone. A resident asking a drug rep to fly their whole residency class to Las Vegas for graduation is so last millennium! But an incredibly wealthy industry like the pharmaceutical industry will not give up there. This is the real thrust of Avorn’s op-ed piece. He discusses the influence that these companies have on the development of “clinical guidelines” by groups of experts in a particular medical field.

Clinical guidelines can be really good and helpful. The information glut is real, sifting through all the data is almost impossible for all the conditions that exist, especially ones that are seen rarely by a particular practitioner. It makes sense that a group of experts in the field review all the evidence in that narrow area and make recommendations that we can count on as accurate and can utilize effectively. But we may be reaching a point where there are too many guidelines, often with conflicting recommendations. Avorn focuses on recent recommendations from the American Association of Clinical Endocrinologists (AACE) on caring for patients with diabetes:

“The A.A.C.E.’s latest guidelines elevate many second- or third-line drugs to more prominent positions in the prescribing hierarchy, rivaling once uncontested go-to medications like metformin, an inexpensive generic. They also emphasize the riskiness of established treatments like insulin and glipizide, which now carry yellow warning labels in the A.A.C.E. summary. Several of the now promoted drugs are expensive newcomers that lack the track records of clinical effectiveness and safety held by the older, potentially displaced treatments. The changes were made, ostensibly, to give physicians more treatment choices for their patients. But there is also concern that they could have been influenced by another factor: the manufacturers of some of these new drugs financially supported the development of the guidelines, and many of the authors are paid consultants to some of those companies.”

Avorn goes on to cite previous examples of expert-generated and industry-sponsored guidelines that have led to overuse of drugs with very bad outcomes for patients. He also cites reliable sources of clinical guidelines, which are based solely on review of the evidence, not the opinions (possibly influenced by money) of experts, “…including the Institute of Medicine, the American College of Physicians and the Cochrane Collaboration, an international network of experts that evaluates clinical research.” He also refers to the practice of “academic detailing”, which he helped to develop[1] [2], in which academic physicians and pharmacists try to counter the impact of drug-industry detailpersons by going out to practicing physicians and presenting evidence-based recommendations.

There are at least two other sources of bias in addition to any direct influence exerted by drug company funding of research, guidelines development, and individual experts. One is the fact that many treatments, particularly when they involve procedures, can increase the income of the individual physicians doing them. Unfortunately, we have seen (and continue to see) the persistence of many procedures for which there is weak evidence overall or for as broad a population as it is being used on, presumably for this reason. The other, less overtly money-driven and thus more insidious, is that many experts are, almost by definition, specialists (well described in this context by the more pejorative “partialists”) who are focused on the impact of a treatment on “their” disease and may miss the potential for negative impact on the patient. An example may be very tight control of blood sugar in people with diabetes; it may improve the outcomes from diabetes, but if it also leads to potentially dangerous episodes of low blood sugar, it may not be a good idea.

Guidelines issued by different organizations also may be in conflict. An excellent example is mammographic screening for breast cancer, discussed in two outstanding “Viewpoint” articles in a recent JAMA. Michael Marmot addresses potential benefits and harms from different guidelines, focusing on UK recommendations[3], and Kachalia and Mello look at the differing US recommendations from the US Preventive Services Task Force (USPSTF), American Cancer Society (ACS), and American College of Radiology (ACR).[4] If a radiologist reads a mammogram as normal, but, following ACR guidelines recommends another in one year, while the clinician is following USPSTF guidelines for less frequent screening, does that place the clinician at increased legal risk? They argue at least for consistent guidelines to be utilized within a single institution.

Finally, there is the potential for unintended outcomes. One of the most reliable evidence-based sources of recommendations is the USPSTF. Its recommendations are based solely on review of the science, which has generated controversy before when those recommendations were unpopular with powerful groups (see mammography guidelines). Their reliability led them to be written into the health reform law, ACA, which mandates insurers pay for preventive services with an “A” or “B” recommendation from USPSTF. However, as articulately described by USPSTF members Steven Woolf and Doug Campos-Outcalt in another recent JAMA[5], this creates the unintended consequence of turning USPSTF into a group that decides whether companies and doctors will make money; you can imagine the lobbying by a company to try to prove that its product deserves a “B” rating!

You sure can imagine it. It is not what we need. Essentially, as long as potential for big profit exists in health care, for providers, drug companies, device manufacturers, insurers, and others, there will be plenty of opportunities -- and actual occurrences – of this, not scientific evidence, guiding medical practice.

And I doubt that this is what you want for your health.

---

[1] Soumerai SB, Avorn J,  “Principles of educational outreach ('academic detailing') to improve clinical decision making.”, JAMA. 1990 Jan 26;263(4):549-56. PMID: 2104640

[2] Fischer MA, Avorn J, “Academic detailing can play a key role in assessing and implementing comparative effectiveness research findings,” Health Aff (Millwood). 2012 Oct;31(10):2206-12. doi: 10.1377/hlthaff.2012.0817.

[3] Marmot M, “Sorting through the arguments on breast screening” JAMA. 2013;309(24):2553-2554. doi:10.1001/jama.2013.6822

[4] Kachalia A, Mello MM, “Breast cancer screening: conflicting guidelines and medio-legal risk”, JAMA. 2013;309(24):2555-2556. doi:10.1001/jama.2013.7100

[5] Woolf SH, Campos-Outcalt D, “Severing the link between coverage policy and the US Preventive Services Task Force”, JAMA. 2013 May 8;309(18):1899-900. doi: 10.1001/jama.2013.3448. 

More on mammography: just because you don't like the results doesn't make research junk science

A recent study published in the New England Journal of Medicine, “Effect of three decades of screening mammography on breast-cancer incidence”, by Archie Bleyer and H. Gilbert Welch[1], has generated enormous controversy. This has been caused by a combination of the study’s findings, the interpretation of them by the popular press, and the reactions of those who have a vested interest in the status quo – a combination that regularly occurs any time anyone publishes any research questioning the current conduct of screening or treatment for breast cancer (see, for example, my blog post Breast cancer screening: conflicting evidence? what are the important questions for health?, October 30, 2010). It happens in other areas, also, but breast cancer is the most common and in some sense most personal of cancers for women, and has a huge advocacy community, as well as powerful groups who profit from both treating it and screening for it.

What did the study show, what does it mean to people, what is the implication for cancer screening and most important, for the health of people (overwhelmingly women) who might get breast cancer? Before addressing these questions, I think it might be helpful to review a little about screening tests, cancer, and people’s hopes and beliefs. People want to not get sick, and especially don’t want to get cancer. If they do get it, they want to be treated and get all better. Of course, despite the use of “cancer” as if it were a single disease, and the existence of organizations such as the American Cancer Society, the federal National Cancer Institute, and the many Cancer Institutes, hospitals, and specialists, it is in fact a variety of diseases that all share certain characteristics but differ in many others. These include commonness, severity, cause, and likelihood of progression or death with or without treatment. Known causes for some cancers include smoking, radiation and viruses, and for many (including most breast cancer) the cause is unknown. It is even more complicated, because just naming the organ affected (breast, lung colon) is not all there is to it, as there are different kinds of cancer that affect the same organ. Whew. This is why the idea of “a cure for cancer” is unlikely; there are cures for some, and may be cures for others in the future, but there is unlikely to be “a” cure.

Some cancers, like breast cancer, are common enough, and well-publicized enough, that women realize that there is a real risk. In that case, the hope is that there exists a screening test that can identify it early enough to intervene and make a positive difference in the outcome. The first thing is that screening tests, by definition, are only for people who have no symptoms of a disease; once they do, a test, even if it is the same test, is no longer “screening” because the probability of the disease is greater in people with a symptom. For example, if one has a lump in the breast, a mammogram may be a good diagnostic test, but it is no longer a screening test. In looking at the criteria for a good screening test, there must be:

1)      A disease a test can screen for (while this seems obvious, doctors still do tests in asymptomatic people that do not effectively screen for any disease),
2)      A reasonable sensitivity and specificity to the test (meaning people with disease are more likely to have a positive test and those without the disease to have a negative test),
3)      A test that is reasonably cheap and acceptable to patients (tests like mammography and colonoscopy, for example, are both more expensive and more uncomfortable than, say, a blood test),
4)      A more definitive test available to say more definitely whether people who screen positive actually have the disease (for most screening, although those who screen positive are more likely to have the disease than those who do not, the majority of those who screen positive still may not have the disease),
5)      An intervention that can be done in the asymptomatic stage that will prevent the disease from progressing (or else, why not wait until it is symptomatic?)

So how does mammography stack up? This is a big part of what is addressed by the Bleyer and Welch study. They have looked at 30 years of screening in the US and found that screening mammograms have uncovered a large number of early-stage breast cancers; in fact, over that time, the number of early-stage breast cancers identified has doubled (from 112 to 234 cases per 100,000 women per year). This is a good – particularly if criterion #5, above, is met – and they can be treated and prevent women from dying or suffering serious morbidity. If this is happening, then (assuming the actual rate of cancer stays the same) the number of cancers diagnosed in later stages, where intervention is less successful, should go down. That is, those cancers detected early and treated would not progress and should mean that many fewer women present with later stage cancer.  Unfortunately, this study demonstrates, that has not occurred. The decrease in late-stage cancer diagnosis has been about 8%, or 8 per 100,000 women per year. So, for every 100,000 women, we are diagnosing an additional 122 early stage cancers, but only decreasing the number of late stage cancers by 8. This means that most of the additional women found by mammography to have early stage breast cancer would not have progressed to late-stage cancer. This, then, leads to their assertion that cancer was over-diagnosed – in 70,000 women in 2008 alone. Any estimate of the number of lives saved by screening and early intervention is inflated if it includes large numbers of women whose cancers would not have progressed. In other words, many of these women diagnosed with cancer, many of whom had non-trivial interventions (surgery, radiation chemotherapy) had cancers that would, basically, have not required any treatment.

Some radiologists who do mammograms have said that this is “junk science” (“Study links mammograms to overtreatment”, Boston Globe, November 21, 2012), but it is clearly not; the findings are the findings. The implications, however, are harder to assess. Does this mean women should not get mammograms? No, certainly that would be a premature conclusion. Some of the women diagnosed with early stage breast cancer would have gone on to develop late stage cancer; if you are one of the 8, you are lucky to have been found; if one of the 114, maybe not, especially if you had to endure the potential harms of chemotherapy or radiation or both, not to mention mastectomy. It may suggest that aggressive interpretation of mammography findings are not warranted. What would be useful would be to identify mammographic findings and subsequent pathology findings on biopsy that required aggressive intervention and those that could be safely followed. One type of breast cancer that is likely to be the subject of future studies is that called ductal carcinoma in situ, or DCIS, which may be more likely than some other types to resolve.

It may well be too soon to know the answer on mammographic screening, but it is clear that it is far from the perfect screening test that everyone would like it to be. We need more studies, and more information, and mostly we need a willingness to accept the accumulated findings of research. Certainly, what we do not need is for those who have a financial stake in screening and treatment to call good research “junk science” because it comes to conclusions that they do not like.

---

[1] Bleyer A, Welch HG, “Effect of three decades of screening mammography on breast-cancer incidence”, NEJM 22Nov2012;367(21):1998-2005.