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Tag: overdiagnosis

Published on Leave a comment on Is It Really Asthma Or Not?

Another study finding overdiagnosis (diagnosing something that isn't likely to cause problems) and misdiagnosis (diagnosing something that isn't there) which leads to overtreatment (unnecessary treatment) - this time of asthma in adults. A new study found that as many as 1 in 3 adults diagnosed with asthma may not actually have the disease. Was this due to spontaneous remission or to initial misdiagnosis? After all, many other diseases mimic the symptoms of asthma, and there is no test that can diagnose asthma with 100% accuracy. The study authors thought that of the 33% without asthma - that many of the adults had been originally misdiagnosed, while others had gone into remission. Excerpts from the thought-provoking site Health News Review:

Is it asthma? Many diagnosed with condition receiving unnecessary or incorrect treatment

As many as 1 in 3 adults diagnosed with asthma may not actually have the disease, according to new research published in the Journal of the American Medical Association (JAMA). Canadian researchers evaluated 613 patients with physician-diagnosed asthma and found that 203 participants (33%) most likely did not have the disease. After an additional 12 months of follow-up of this latter group, 181 subjects (30%) continued to exhibit no clinical or laboratory evidence of asthma.

This study, and its accompanying editorials, hit on a theme we’ve often raised with regard to cancer and many other chronic diseases: overdiagnosis leading to overtreatment. But it also raises the specter of misdiagnosis from the get-go, which can lead to erroneously treating a condition that isn’t there. The Canadian results may also confuse many of us who have grown accustomed to news stories warning us that asthma is on the rise. So which is it? More asthma which needs more aggressive treatment or less asthma warning against overtreatment?

“I think asthma is both overdiagnosed and underdiagnosed,” says Dr. Nancy Ott, an allergy and immunology specialist in practice for 28 years. “We don’t have a specific test that is definitive for asthma, and the diagnosis is nuanced. You need to look at the symptoms, the patient’s history, their family history, and the objective tests collectively. And I think we need to be much more strict in what constitutes asthma because the symptoms alone overlap with so many other conditions.”

This is not a message we hear nearly enough in news stories: the diagnosis of asthma, although common, is anything but cut-and-dried. In outpatient clinics – where most asthma is diagnosed – time pressures can lead to incomplete evaluations, which lead to misdiagnoses (which, by the way, includes over-, under-, and no diagnoses), and this can ultimately lead to patients suffering physically, emotionally and financially.

“We think that a large proportion of them had been misdiagnosed in the first place and another proportion that (was) a bit smaller had actually gone into remission, their asthma was no longer active,” said principal investigator Dr. Shawn Aaron, head of respirology at the University of Ottawa. Medical textbooks say about six per cent of people with asthma go into remission over a 10-year period, said Aaron. “But we found at least 20 per cent had gone into remission.” However, “one of the main messages I want to get across is that some people are being misdiagnosed because they’re not being properly investigated to begin with,” he said from Ottawa.

Which brings up an important point: the symptoms of asthma overlap with several other diseases. In the Canadian study, 12 people, or 2 percent of the participants, had serious conditions other than asthma, like heart disease and pulmonary hypertension. Others had problems such as hyperventilation from panic attacks, and gastroesophageal reflux (GERD). These latter two conditions frequently mimic asthma. As does vocal cord dysfunction. Suffice to say that if you were to take each of the classic symptoms of asthma individually, the list of diseases associated with that symptom is well over a dozen.

Published on Leave a comment on Breast Cancer Study Finds A Lot of Overdiagnosis

Another large study looking at screening mammograms for breast cancer has raised the issue of overdiagnosis and overtreatment once again. The purpose of mammography screening is to find cancer when it is small and so prevent cancer from growing and becoming advanced cancer. However, the researchers did not find this - there was a major increase in finding small cancers (the kind that may grow so slowly as to never cause any problems or that may even regress), but the rate of advanced cancers stayed the same.

The problem of overdiagnosis (finding small tumors that may never cause problems) and overtreatment (treating unnecessarily), which is leading to medical experts "rethinking cancer screening" is a major shift in how cancer screening is being viewed for a number of cancers. This is because studies show that overall death rates are basically the same in screened vs non-screened persons for mammography, colon, prostate, and lung cancer screening (see post). The view of how cancer grows and spreads may have to be reexamined and changed. One possibility suggested by Dr. H. Gilbert Welch is that aggressive cancer is already "a systemic disease by the time it's detectable" (Oct. 28, 2015 post).

The following excerpts are from the thoughtful review of the study in Health News Review: Overdiagnosis of ductal carcinoma in situ: ‘the pathology equivalent of racial profiling’

Danish researchers are providing new evidence that many breast cancers found via screening mammograms don’t need to be treated. Women with these non-threatening tumors are said to be “overdiagnosed” with breast cancer. Overdiagnosis occurs when breast screening such as mammography detects small, slow-growing cancers that may never cause the patient any trouble. Yet, women diagnosed with such tumors are exposed to very real harms–possible surgery, chemotherapy, radiation, and living life as a “cancer patient.”

How much overdiagnosis are we talking about? If you don’t include cases of ductal carcinoma in situ (DCIS) in the tallies, anywhere from 14.7% to 38.6% of breast cancers found via screening represent overdiagnosis, the study authors found. The rate ranges from 24.4% to as high as 48.3% when DCIS is included.

DCIS is a collection of abnormal cells inside a milk duct that may–but usually doesn’t–break out to become invasive and potentially lethal cancer. About 60,000 women are told they have DCIS each year in the United States. Some experts estimate that up to 80% of women with DCIS found via screening may not need any treatment at all–and instead should just keep an eye on things. Obviously, women need to be fully and accurately informed about the benefits and risks — including the risk of overdiagnosis — before embarking on any decision to get screened for breast cancer or choosing a course of action following a diagnosis.

Otis Brawley, MD, Chief Medical Officer for the American Cancer Society, says it’s been difficult for modern medicine to wrap its brain around the concept of overdiagnosis. The natural inclination is to assume that cancerous-looking cells “will grow, spread, and eventually kill,” he writes in an editorial accompanying the Danish study. “However, some of these lesions may be genomically predetermined to grow no further and may even regress. In many respects, considering all small breast lesions to be deadly and aggressive types of cancer is the pathologic equivalent of racial profiling.

Excerpts from the original study from the Annals of Internal Medicine: Breast Cancer Screening in Denmark: A Cohort Study of Tumor Size and Overdiagnosis

Background: Effective breast cancer screening should detect early-stage cancer and prevent advanced disease. Objective: To assess the association between screening and the size of detected tumors and to estimate overdiagnosis (detection of tumors that would not become clinically relevant).... Setting: Denmark from 1980 to 2010. Participants: Women aged 35 to 84 years. Intervention: Screening programs offering biennial mammography for women aged 50 to 69 years beginning in different regions at different times.

Conclusion: Breast cancer screening was not associated with a reduction in the incidence of advanced cancer. It is likely that 1 in every 3 invasive tumors and cases of DCIS (ductal carcinoma in situ) diagnosed in women offered screening represent overdiagnosis (incidence increase of 48.3%).

Breast screening is associated with a substantial increase in the incidence of nonadvanced tumors and DCIS (ductal carcinoma in situ) in Denmark but not with a reduction in the incidence of advanced tumors, and the overdiagnosis rate is substantial. These findings support that screening has not accomplished the promise of a reduction in invasive therapy or disease-specific mortality.

Published on Leave a comment on Overdiagnosed and Overtreated For Thyroid Cancer

The problem of overdiagnosis and overtreatment has been discussed in a number of posts on this site. And back in April 15, 2016 I posted that a type of noninvasive thyroid cancer had just been reclassified as a noncancer. Now a study in the prestigious New England Journal of Medicine finds that looking at 12 countries (including the USA): "Overall, we estimate that more than 470,000 women and 90,000 men may have been overdiagnosed with thyroid cancer over two decades in these 12 countries..."

The researchers further state that the "vast majority" of these patients received a diagnosis of small, low-risk papillary carcinomas, and they underwent surgery and other treatments, but these interventions have not shown "benefits in terms of improved survival". In fact, studies show that watchful waiting is just as effective. From Medscape:

Thyroid Cancer Overdiagnosis in Half a Million Patients

A large fraction of thyroid cancer cases represent overdiagnoses, and at least half a million patients, most of them women, may have received unnecessary surgery and other cancer treatments, say researchers from the the International Agency for Research on Cancer (IARC), in Lyons, France.

Their warning about an epidemic of thyroid cancer overdiagnosis comes from an analysis of cancer registry data from 12 countries published August 17 in the New England Journal of Medicine . Salvatore Vaccarella, PhD, and colleagues at the IARC estimate that more than 470,000 women and 90,000 men may have been overdiagnosed withthyroid cancer in 12 "high-income" countries (Australia, Denmark, England, Finland, France, Italy, Japan, Norway, Republic of Korea, Scotland, Sweden, and the United States) from 1987 to 2007.

Most of these thyroid cancers were small, low-risk papillary carcinomas, they note. The "vast majority" of these patients underwent total thyroidectomy, and a "high proportion" also received neck lymph-node dissection and radiotherapy, but these interventions do not have "proven benefits in terms of improved survival," the researchers point out...."However, if we take the most recent available period, 2003 - 2007, as typical of current practice, we estimate that overdiagnosis in women accounts for 90% of thyroid-cancer cases in South Korea; 70 to 80% in the United States, Italy, France, and Australia; and 50% in Japan, the Nordic countries, and England and Scotland."

The overdiagnosis is blamed on increasing medical surveillance and the introduction of new diagnostic techniques, such as neck ultrasonography (since the 1980s) and, more recently, CTscanning and MRI. This new technology has led to the detection of a large number of indolent, nonlethal diseases that exist in abundance in the thyroid gland of healthy people of any age, the researchers comment, adding that most of these tumors are very unlikely to cause symptoms or death....."It is fair to say that the large number of thyroid cancers being diagnosed represent an epidemic of diagnosis, or an epidemic of medical testing, rather than an epidemic of true disease."

These results also mean that most patients are receiving treatment that does not benefit them and that subjects them to risks of injury to the voice, permanent hypoparathyroidism, as well as the attendant risks of radioactive iodine treatment, he pointed out.  

The researchers caution against systematic screening for thyroid cancer and overtreatment of nodules <1 cm. "Watchful-waiting approaches should be considered a research priority and a preferable option for patients with low-risk papillary thyroid cancers," they say. Studies from Japan suggest that immediate surgery and watchful waiting are equally effective in preventing mortality, Dr Vaccarella said. One study showed that of 1235 patients with papillary microcarcinomas, only 3.5% experienced clinical progression of disease during a 75-month follow-up, and there were no deaths.

At Memorial Sloan Kettering Cancer Center, active surveillance has been offered to patients with low-risk, small, intrathyroidal cancers for several years, Dr Morris said. "Our results have mirrored the Japanese results, and fewer than 5% of patients end up showing any signs of tumor growth under close observation," he said.

Published on Leave a comment on Noninvasive Thyroid Cancer Is No Longer Cancer

For the first time ever, one type of cancer has been reclassified as a non-cancer. An international panel of pathologists and clinicians has reclassified a type of thyroid cancer to reflect that it is noninvasive and has a low risk for recurrence.The panel renamed encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). There has been concern for a while of the costs (financial, physical, and mental) of the overdiagnosis and overtreatment for something that won't spread (it's "indolent" and "low-risk").

There have been discussions for some time now in the medical community regarding the move away from the word "cancer" in the description of early stages of both breast and prostate cancer. In 2013, a medical team sanctioned by the National Cancer Institute proposed that a number of premalignant conditions, including ductal carcinoma in situ and high-grade prostatic intraepithelial neoplasia, should no longer be called "cancer." Instead, the conditions should be labeled something more appropriate, such as indolent lesions of epithelial origin (IDLE), the group suggested. " Use of the term 'cancer' should be reserved for describing lesions with a reasonable likelihood of lethal progression if left untreated," the group said at the time.

From Futurity: NONINVASIVE THYROID ‘CANCER’ ISN’T CANCER

The reclassification of a noninvasive type of thyroid cancer that has a low risk of recurrence is expected to reduce the fears and the unnecessary interventions that come with a cancer diagnosis, experts say. The incidence of thyroid cancer has been rising partly due to early detection of tumors that are indolent or non-progressing, despite the presence of certain cellular abnormalities that are traditionally considered cancerous, says senior investigator Yuri Nikiforov, professor of pathology at the University of Pittsburgh.

“This phenomenon is known as overdiagnosis,” Nikiforov says. “To my knowledge, this is the first time in the modern era a type of cancer is being reclassified as a non-cancer. I hope that it will set an example for other expert groups to address nomenclature of various cancer types that have indolent behavior to prevent inappropriate and costly treatment.”

In particular, a tumor type known as encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) has increased in incidence by an estimated two- to three-fold over the past 20 to 30 years and makes up 10 to 20 percent of all thyroid cancers diagnosed in Europe and North America. Although studies have shown EFVPTC is not dangerous, it is typically treated as aggressively as other types of thyroid cancer. At the recommendation of the National Cancer Institute, the panel sought to revise the terminology and to see if the word “cancer” could be dropped from its name.

As reported in JAMA Oncology, two dozen experienced pathologists from seven countries and four continents independently reviewed 268 tumor samples diagnosed as EFVPTC from 13 institutions....In a group of more than 100 noninvasive EFVPTCs, there were no recurrences or other manifestations of the disease at a median follow-up of 13 years. They decided to rename EFVPTC as “noninvasive follicular thyroid neoplasm with papillary-like nuclear features” or NIFTP. The new name cites key features to guide pathologists in diagnosis, but omits the word “cancer,” indicating that it need not be treated with radioiodine or other aggressive approaches.

“We determined that if NIFTP is carefully diagnosed, the tumor’s recurrence rate is extremely low, likely less than 1 percent within the first 15 years,” Nikiforov says. “The cost of treating thyroid cancer in 2013 was estimated to exceed $1.6 billion in the US. Not only does the reclassification eliminate the psychological impact of the diagnosis of ‘cancer,’ it reduces the likelihood of complications of total thyroid removal, and the overall cost of health care.”

Published on Leave a comment on Rethinking Cancer Screening

A provocative and thought-provoking article in which the title says it all: Cancer screening has not been shown to 'save lives'. The following is from the Medscape analysis/reporting of the original British Medical Journal article and accompanying editorial ( BMJ. January 2016, Article, Editorial), and both the original and Medscape analysis are well worth reading. From Medscape:

Cancer Screening Has Not Been Shown to 'Save Lives'

Debates about cancer screening programs tend to focus on when to start, who to screen, and the frequency of screening. But some investigators are asking a far more provocative question: Do screening programs actually save lives?

We do not know the answer to that question, and would need to conduct massive clinical trials to find out, said Vinay K. Prasad, MD, MPH, assistant professor of medicine at the Oregon Health Sciences University in Portland."Proponents of cancer screening say that screening tests have been shown to save lives. What we're trying to show is that, strictly speaking, that's sort of an overstatement," he told Medscape Medical News.

In an analysis published online January 6 in the BMJ, Dr Prasad and his colleagues argue that although cancer screening might reduce cancer-specific mortality, it has not conclusively been shown to have an effect on overall mortality. The researchers go on to suggest that the harms of screening might actually contribute to overall mortality rates. These potential harms include false-positive results that lead to unnecessary biopsies or therapeutic interventions and overdiagnosis, in which treatment is delivered for a condition that is unlikely to affect patients during their natural lifespans.

"There are two chief reasons why cancer screening might reduce disease-specific mortality without significantly reducing overall mortality," the researchers write. "Firstly, studies may be underpowered to detect a small overall mortality benefit. Secondly, disease-specific mortality reductions may be offset by deaths due to the downstream effects of screening." "The bar to say that screening saves lives should be overall mortality, and we haven't met that bar," Dr Prasad told Medscape Medical News.

The rationale for cancer screening is based on the assumptions that screening will reduce deaths from cancer and that lowering cancer-specific deaths will decrease overall mortality. These assumptions remain unsupported by facts, Dr Prasad's team contends.

They illustrate this point with data from the National Lung Cancer Screening Trial (NLST). Although there was a 20% relative reduction in lung cancer deaths with low-dose CT screening, compared with chest x-ray, and a 6.7% relative reduction in overall mortality, the absolute reduction in risk for overall mortality was just 0.46%....The team also notes that "the benefit in lung cancer mortality of CT screening (estimated to avert over 12,000 lung cancer deaths in the United States annually) must be set against the 27,034 major complications (such as lung collapse, heart attack, stroke, and death) that follow a positive screening test."

The decision to undergo screening should be part of an informed discussion between the patient and clinician that takes into account personal preferences and the risks and benefits of screening. Dr Prasad explained. "Declining screening may be a reasonable and prudent choice for many people," the researchers write. "Doctors should be comfortable with whatever choice people make when they hear about all the potential benefits and the known harms," Dr Prasad added.

However, in an accompanying editorial, Gerd Gigerenzer, PhD, from the Max Planck Institute for Human Development in Berlin, argues that "rather than pouring resources into 'megatrials' with a small chance of detecting a minimal overall mortality reduction, at the additional cost of harming large numbers of patients, we should invest in transparent information in the first place." He explains that information about screening should be presented in a "fact box" that lays out the benefits and risks of mammography with numbers for how many women would be affected."It is time to change communication about cancer screening from dodgy persuasion into something straightforward," he concludes.

Richard L. Schilsky, MD, chief medical officer for the American Society of Clinical Oncology (ASCO), said that although, in general, ASCO supports cancer screening, "it's a very imperfect process....The often high variability in the natural history of many cancers has been the source of particular confusion and uncertainty surrounding screening, he noted. For example, there is little value in screening for aggressive cancers for which interventions are unlikely to make a difference in outcomes, no matter how early the disease can be detected. Conversely, "if the cancer is never going to kill you, no matter what the doctors do, then screening won't help either," he said. Additionally, there are some cancers for which treatments are sufficiently effective that they can be successfully managed whether they are diagnosed at an early or later stage. "When you consider all these factors, the number of individuals who will actually benefit from detecting a screen-detected cancer is very small," Dr Schilsky said.

Published on Leave a comment on Overdiagnosis of Thyroid Cancer?

The issue of overdiagnosis and overtreatment rears its head again - this time in a study looking at thyroid cancer detection and death rates. The death rate from thyroid cancer has stayed the same since 1935, as has the number of thyroid cancers presenting with symptoms of thyroid cancer. But...the number of new cases of silent thyroid cancer -- the kind where patients have no symptoms -- almost quadrupled in recent years, and these are the tiny cancers that probably won't cause a problem in the person's lifetime. The researchers then discuss how NOT to find these tiny silent thyroid cancers, so as to avoid overdiagnosis and the harms of overtreatment. From Science Daily:

Increased detection of low-risk tumors driving up thyroid cancer rates, study finds

Low-risk cancers that do not have any symptoms and presumably will not cause problems in the future are responsible for the rapid increase in the number of new cases of thyroid cancer diagnosed over the past decade, according to a Mayo Clinic study published in the journal Thyroid. According to the study authors, nearly one-third of these recent cases were diagnosed when clinicians used high-tech imaging even when no symptoms of thyroid disease were present.

"We are spotting more cancers, but they are cancers that are not likely to cause harm," says the study's lead author, Juan Brito Campana, M.B.B.S., an assistant professor of medicine at Mayo Clinic. "Their treatment, however, is likely to cause harm, as most thyroid cancers are treated by surgically removing all or part of the thyroid gland. This is a risky procedure that can damage a patient's vocal cords or leave them with lifelong calcium deficiencies." Dr. Brito says harm is not limited to physical suffering. "Treatment can cause financial hardship for patients and their families and for society as a whole, as millions of dollars are spent for unnecessary and problematic surgeries," he says....At the same time, the incidence of thyroid cancer is increasing more rapidly than that of any other cancer and is on track to become the third most common cancer in women.

In this study, Dr. Brito and his colleagues drew on data from the Rochester Epidemiology Project. They analyzed the records of 566 men and women who were diagnosed with thyroid cancer in Olmsted County, Minnesota, between 1935 and 2012. Specifically, they examined the number of new cases of thyroid cancer, the deaths due to the disease, and the method of diagnosis.

Researchers found that the number of new cases of thyroid cancer doubled in recent years -- from 7.1 per 100,000 people from 1990 to 1999 to 13.7 per 100,000 people from 2000 to 2012. Over the same period, the number of new patients with thyroid cancer presenting with symptoms of thyroid cancer remained the same. In contrast, the number of new cases of silent thyroid cancer -- the kind where patients have no symptoms -- almost quadrupled. The proportion of patients with thyroid cancer who die of the disease has not changed since 1935.

The study found that the most frequent reasons for identifying silent thyroid cancer were review of thyroid tissue removed for benign conditions (14 percent); incidental discovery during an imaging test (19 percent); and investigations of patients with symptoms or palpable nodules that were clearly not associated with thyroid cancer, but triggered the use of imaging tests of the neck (27 percent)."We are facing an epidemic of diagnosis in thyroid cancer," says Dr. Brito. 

Researchers say one approach to curtail the detection of these lesions would be to limit the use of certain imaging technologies. Another tactic would be to engage patients in deliberating their treatment options. In many cases, active surveillance may be preferred over surgery by patients with small, relatively benign cancers that could take decades to grow to any appreciable size or cause life-threatening problems. Dr. Brito thinks something as simple as not using the word "cancer" to refer to these small and silent thyroid lesions could reduce the number of unnecessary treatments for patients with a more favorable prognosis. Rather than calling these lesions thyroid cancer, he would recommend a less emotionally charged term, such as papillary lesions of indolent course.

Thyroid gland. Credit: Mayo Foundation for Medical Education and Research

Published on

 The following article supported what I have been reading over the past few years: that medical tests and treatments also have downsides, that it is possible to "know too much", that more harm than benefits can occur from certain tests, procedures, and medicines, and lifestyle changes (eat a less processed more plant-based diet, move more, and don't smoke) can be better than some medicines or certain procedures. The doctor mentioned in this article (Dr. H. Gilbert Welch) recently published a book aimed at the general public which I just read and highly recommend: Less Medicine, More Health. Dr. Welch is an academic physician, a professor at Dartmouth Medical School, and a nationally recognized expert on the effects of medical testing. In 2012 he published the well regarded and more technical and in-depth book on this issue: Overdiagnosed: Making People Sick in the Pursuit of Health. From The Atlantic:

The Downside of Medical Screening

If you had a disease, and you could find out sooner rather than later, why wouldn’t you?Medicine has long focused on early detection of diseases as part of a move toward preventive care. But imperfect tests, false positives, and overdiagnosis mean that sometimes the tests do more harm than good, and in recent years, there have been more recommendations to reduce some kinds of screening, including pap smears, colonoscopies, mammograms, and even annual pelvic exams.

“This is something we all need to understand, the two sides of early detection. It does help people, but it’s almost guaranteed to harm others,” said H. Gilbert Welch, a professor of medicine, public policy, and business administration at Dartmouth College, and author of the book Should I Be Tested for Cancer? (He reveals his answer in the book’s subtitle: “Maybe not.”)

The more you look for disease, the more you find it. And in the case of cancer, it’s hard for doctors to know if what they find is dangerous and needs to be addressed, or if it’s just a small tumor that won’t grow and poses no threat. “We can’t be sure which is which, so we treat everybody,” Welch explained at the Aspen Ideas Festival’s Spotlight Health session. “That means we’re treating people who will never experience problems from their disease.”

But they may experience problems from the treatment.The panel gave the example of prostate cancer, which is very common in men—one in seven American men will be diagnosed with it in their lifetimes. “But it turns out a lot of these cancers are very indolent,” said Jessica Herzstein, a preventive-medicine consultant and member of the U.S. Preventive Services Task Force. Around 30 to 40 percent of men who’ve been treated for prostate cancer likely had “slow-growing tumors that would never have become a threat to the man’s lifespan or health,” according to the Prostate Cancer Foundation.

In other words, “you’re going to die with them, not of them,” Herzstein said, “and the treatments are very very harmful.” Radiation therapy, for example, can cause incontinence and erectile dysfunction, and hormone therapy can cause osteoporosis and depression.

The possibility of a false positive is another downside. Not only could it lead to more invasive follow-up tests or treatments that aren’t needed, but it can also give patients unnecessary anxiety.“If we resolve the test by saying ‘The test was wrong, you’re fine!’, that’s one thing,” Welch said. “But most false alarms aren’t resolved that way. [It’s more like] ‘You don’t have cancer, but you have some abnormality that possibly puts you at a higher risk for cancer, but we’re not going to do anything about it. I think that’s where there can be [mental] harm.”

Ultimately, it comes down to a weighing of the benefits and the harms, and, in the absence of clear evidence, the preferences of the patient. The U.S. Preventive Services Task Force helps identify which tests are beneficial by evaluating and grading them. It gives tests an A if there’s a high certainty of substantial benefit, a B if there’s moderate certainty of substantial benefit, a C if there’s moderate certainty of a small benefit, a D if there’s moderate or high certainty of no benefit, and an I if the evidence is just too insufficient to say.

The task force gave prostate cancer screening a D. HIV screening got an A. For breast cancer screening, an always-controversial topic, the results vary. Breast self-exams got a D. Mammograms got a B, but only for women between 50 and 74 years old. For women in their 40s, the grade is a C, meaning the task force recommends patients and physicians discuss and decide together.

Before getting a screening test, patients should think about what would happen if they get a positive result, and if they’d be ready for it, Welch advised. “If I were to go through this, and have this diagnosis, would I want to have this surgery?” Herzstein asked, posing a hypothetical. Would you want to undergo the biopsy, the chemo, whatever treatments come next? “Maybe you don’t even want to go there if there is no treatment for the disease,” she added. Welch gives an example. “With Alzheimer’s disease that’s a fundamental question: What are you going to do with a positive result?” he asked.