Opinion: A ‘more, more, more’ approach to cancer screening is misleading and harmful

Enormous progress has been made against cancer in the last 50 years — at least medically. Our emotional relationship with the emperor of all maladies, however, is years out of date, and that lag is causing great harm.

Many cancers can now be cured or treated as chronic conditions. In his 2015 memoir “The Death of Cancer,” Vincent DeVita, a former director of the National Cancer Institute, estimates it’s as many as two-thirds. Yet most people, when asked for the first word that comes to mind when they hear the word cancer, still answer “death.”

That’s just one reason why the fear of cancer hasn’t caught up to the progress that’s been made in treating it. Another is the heavy emphasis on the benefits of screening — checking healthy people for hidden cancer — with no mention of the harms screening can also cause. Consider the glaring difference between two major reports about cancer screening issued from two highly reputable organizations in connection with World Cancer Day 2021.

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One, from the President’s Cancer Panel, features a host of recommendations to encourage more Americans to participate in screening programs. The other, a guide for European policy makers from the World Health Organization, emphasizes that screening is not right for everybody and in many cases does more harm than good, either from frightening false positive results or from the excessive treatment people choose when screening finds a type of cancer so small, so localized, and so slow-growing (or even nongrowing) that it never would have caused any harm.

Decades of screening with ever-more sensitive technologies have revealed the extent of this problem. Yet while the WHO guide warns that screening has benefits and risks, that caution is nowhere to be found in the President’s Cancer Panel report.

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Most religions would be lucky if their followers believed in their teachings as deeply as the public believes in cancer screening.

Results of a study published in JAMA are typical of what researchers often find:

  • 87% of adults believe cancer screening is “almost always a good idea.”
  • 98% of people who had endured a false positive — a test suggesting the presence of cancer that later turned out not to be cancer at all — said they were still glad they had done the screening test, even though half of them described the experience as “the scariest time in my life.”
  • 58% of women said they would disregard suggestions from their doctors to screen less often for breast cancer, and 77% of men said that for prostate cancer. Both of these cancers include subtypes that rarely do any actual harm.

Other studies have found that people still want cancer screening even after they’re expressly told that the same number of people die with or without it. A remarkable study, “A Bias for Action in Cancer Screening,” found that people want cancer screening even when they know not only that it won’t save their lives but that it might harm them. Laura Scherer and colleagues reported in 2019 that after study participants were told about a cancer screening test (mammography for breast cancer and PSA [prostate specific antigen testing] for prostate cancer) and were then warned that “years of research have unquestionably shown that the test does not extend life or reduce the chance of death” and that the test could “lead to unnecessary treatment,” 51% wanted the test anyway.

Belief in screening makes psychological sense. People tend to fear cancer more than any other disease, in part because of the common belief that being diagnosed with cancer is an inescapable death sentence. Against the fear of a threat people feel they have little control over, screening feels empowering. It offers a way to fight back. As the authors of the JAMA study mentioned earlier put it, “some people believe that there is something to be gained from screening even when the test does not save or extend lives, and that something is information. Cancer screening information may provide reassurance and reduce uncertainty.”

Or as George Crile Jr., the oncologist who treated “Silent Spring” author Rachel Carson, put it in his 1955 book “Cancer and Common Sense,” which warned of the dangers of what he called cancerphobia: “The demand for these tests stems from the philosophy of fear.”

So there has been pressure for ever-more cancer screening. But as its use has expanded and technologies have gotten better and better at finding tiny cancers earlier and earlier, it has come to light that even though some suspicious cells meet the criteria for cancer when they are biopsied and inspected under a microscope, they almost never grow or spread to other tissues or cause any harm in an individual’s lifetime. This is known as overdiagnosis.

Low-grade ductal carcinoma in situ, a common type of breast cancer, is one such disease. Slow-growing prostate cancer is another. An estimated 80% or more of thyroid cancers are so-called papillary cancers, a type that is usually so small and slow-growing — or nongrowing — that people would have never known they had it except for the results of a screening test.

Yet most people who hear the dreaded words “You have cancer,” even these essentially nonthreatening types of cancer, choose aggressive surgery or treatment to remove or destroy it, even when their doctors suggest — even recommend — regular monitoring, known as active surveillance, instead of aggressive treatment.

For a forthcoming book about the harm caused by sometimes excessive worry about cancer, I’ve made rough calculations — based on a wide range of primary and secondary sources and peer-reviewed by three health care economists at the U.S. Agency for Healthcare Research Quality — about the costs associated with the treatment of overdiagnosed cancer. They are staggering in terms of health, lives, and money.

Since 1977, when mammography began to be widely used to screen for breast cancer, roughly 1.2 million women have had surgery for low-grade ductal carcinoma in situ. Approximately 1,000 of them died and roughly 250,000 have experienced long-term post-mastectomy pain syndrome as a result of more aggressive treatment than they needed.

PSA testing for prostate cancer began in 1992. Since then, I estimate that 600,000 men have had surgery or radiation therapy to treat a prostate cancer that would never have harmed them. Approximately 500 of these men died from the treatment and 375,000 experienced long-term erectile dysfunction, 112,000 experienced long-term urinary incontinence, and 84,000 had trouble controlling their bowels.

From 1995, when ultrasound technology started to be used to screen for growths in the thyroid gland, surgery for a cancer that never would have harmed the patient killed roughly 700 people. More than 200,000 were left with damaged salivary glands, which causes difficultly and pain eating, swallowing, and speaking. Another 34,000 needed surgery to repair damaged vocal cords, and 5,100 had some degree of permanent damage to their ability to speak. And an estimated 13,000 experienced permanent hypoparathyroidism (underactive parathyroid glands), symptoms of which include muscle aches or spasms, fatigue, hair loss, dry skin, and depression.

The financial cost of this overtreatment is staggering. By my admittedly rough calculations, the total yearly cost to the health care system for the clinically unnecessary treatment of overdiagnosed cancers is $16 billion — $12.6 billion to private insurance and $3.4 billion to Medicare. That’s approximately 8% of the $209 billion the National Cancer Institute estimates was spent on all cancer care in the U.S. in 2020.

And that doesn’t include the cost of overscreening: the millions of asymptomatic individuals with no genetic or other risk factors for cancer who are younger or older than screening guidelines call for who get screened anyway.

The U.S. Preventive Services Task Force (USPSTF), which reviews research on health care screening, recommends which types of screening, for which diseases, and for which people, do more good than harm. The USPSTF recommends that mammography every other year is beneficial for women between the ages of 50 and 75. Research done for my book by Dr. Ingrid Hall of the Division of Cancer Control and Prevention at the U.S. Centers for Disease control and Prevention found that in 2018, 15.6 million women under age 50 and 5.7 million over age 75 had mammograms anyway.

The USPSTF has found that PSA blood test screening for prostate cancer leads to high rates of overdiagnosis and does more net harm than good, and as a result gives such screening a “C” rating, meaning no recommendation. The task force only advises men between the ages of 55 and 69 to talk to their doctors about whether to have this test. The task force gives PSA screening for men 70 and over a “D” rating, as in don’t do it. The CDC reports that in 2018, 3.9 million U.S. men under age 50 and 6.2 million men over age 75 had a PSA test anyway.

The USPSTF gives screening for colorectal cancer for men and women between the ages of 50 and 75 an “A” rating, which is a strong recommendation; screening for those between the ages of 45 and 49 gets a more tepid “B” recommendation. Yet the CDC reports that in 2018, 11.5 million over 75 had either a stool sample or a colonoscopy to check for cancer.

Commercial insurance and Medicare pay for nearly all of this screening. According to the calculations I’ve made for the book, the cost for overscreening people who fall outside the USPSTF recommendations — people who research shows are more likely to be harmed than helped — is an estimated $16 billion a year for private insurance and $4.6 billion for Medicare, a total of $21.5 billion.

A few medical organizations, like the American Academy of Family Physicians, and cancer advocacy groups, like the National Breast Cancer Coalition, are starting to warn people that cancer screening can cause significant harm. And more news organizations are now reporting on the problem of overdiagnosis, although even these reports usually fail to caution that cancer screening is what leads to those diagnoses in the first place.

But the overwhelming message about cancer screening to the public from nearly every source is “more, more, more.”

There is no question that some cancer screening saves lives. The USPSTF finds that for some people, screening for breast, colorectal, cervical, and lung cancer provides a net benefit. But the public is not hearing the whole story about cancer screening. While many Americans who undergo screening are more likely to be helped than harmed, millions of others who choose to be screened for cancer are actually more likely to be harmed than helped.

Without clear and balanced information about the risks and benefits of this double-edged sword, a “more, more, more” approach to screening that taps into the public’s fears is misleading, and harmful, and a big part of why the persistently high concern about cancer hasn’t caught up to the progress that’s been made in treating it.

David Ropeik is a retired instructor at the Harvard T.H. Chan School of Public Health, a consultant in risk communication, and author of the forthcoming book with the working title “Rethinking Our Fear of Cancer” (Johns Hopkins University Press, in press).

Source: STAT