Consider the Benefits and the Harms of Cancer Screening

Suppose your doctor told you that you should not have that cancer screening test because, at your age, it will more likely harm than help you. Would you listen to their advice? Two new studies add to the evidence that many people don't.

Doctors don’t often give such advice, of course. Most doctors, like most of us, think of cancer screening as always helpful, unaware of (or dismissing of) a body of evidence that screening can also cause harm in several ways. False positive results, for example, scare people into thinking they have cancer when it turns out they don’t. Many remain more fearful of cancer for the rest of their lives and change how they live as a result.

Screening finds many cancers—common types of breast, prostate, thyroid, and even lung cancer—that are “overdiagnosed,” disease that looks like cancer under a microscope but which never spreads and grows so slowly, or not at all (or even disappears on its own) that it would never harm the person who has it. Most people diagnosed with these types of cancer choose surgery, radiation, or other aggressive treatments—“fear-ectomies"—to eliminate a disease that understandably scares them but poses little or no actual threat. Thousands of these people suffer all sorts of serious side effects, and some die from treatment they didn’t clinically require.

What drives cancer “overscreening”? Fear. Since the 1930’s, we have feared cancer more than any other disease, even heart disease, which kills far more of us. Screening provides a reassuring sense of control of a disease many still believe carries an automatic death sentence. Consider the findings of a 2004 study:

• 87 percent of adults believe cancer screening is “almost always a good idea.”
• 66 percent would want to be tested for cancer even if nothing could be done.
• 56 percent would want to be tested for cancers that would never cause problems in their lifetime, even if those cancers were left untreated.
• 58 percent of women and 77 percent of men said that they would disregard suggestions from their doctors to screen less often for breast or prostate cancer.[i]

A couple of recent studies highlight this phenomenon. In one, Elizabeth Berger, Assistant Professor of Surgery at the Yale University School of Medicine, reported that many older women who have had breast cancer once subsequently undergo mammograms that aren’t likely to help them, given their expected remaining lifespan and the fact that breast cancer in older women grows more slowly. Fifty-one percent of women who, because of their age and other health conditions, had an expected remaining lifespan of just one year still received at least one mammogram within 12 months of their death. Among women with an expected remaining lifespan of six to ten years, 82 percent received at least one mammogram, and 62 percent received five.

Berger made it clear what this means:

For women with significant competing mortality risks unlikely to die of a breast cancer diagnosed at an older age, mammography brings little benefit. Ongoing surveillance mammography in these patients may lead to over-diagnosis and over-treatment of cancers that potentially would not harm patients if left untreated.

The same thing happens with men and prostate cancer. A recent study reported that 55 percent of men aged 70-to-74, 52 percent of men aged 75-to-79, and 39 percent of men 80 and older still had PSA tests. That’s although the U.S. Preventive Services Task Force (the USPSTF generates government screening recommendations for all sorts of diseases) firmly recommends against such screening because at those ages, given that most prostate cancers are slow-growing, men with the disease are likely to die with it but not from it. Finding it, though, scares many older men into “fear-ectomies"—surgeries and radiation treatments that won’t extend their lives but which can cause serious side effects, including death itself.

A broader look at the problem of overscreening produces sobering results. The CDC found that in 2017:

• Despite the USPSTF recommendation that only women aged 50 to 74 have an every-other-year mammogram, 15.6 million US women under 50, and 5.7 million over 74, said they’d had one sometime in the past 10 years anyway.
• The USPSTF recommends only that men between 50 and 75 talk to their doctors about maybe having a PSA test. Yet 3.9 million U.S. men below 50 and 6.2 million men over 75 had a PSA test anyway.
• Colorectal screening (either a stool sample or a colonoscopy) was recommended for people from aged 50 to 75—in 2018, the recommendation was broadened to include those aged 45 to 49—yet 251,000 people between 40 and 50, and 1.1 million over 75, had a colorectal screen.

A rough estimate finds that cancer screening for those outside the groups for which it is recommended costs the U.S. healthcare system a staggering $9.2 billion per year. The clinically unnecessary treatment of overdiagnosed cancers, nearly all found by screening, costs the healthcare system roughly $5.3 billion annually. And that treatment leaves tens of thousands of people suffering physical and psychological side effects ranging from moderate to death.

Fear Essential Reads

Progress in the Fight Against Cancer-Phobia

How to Overcome the Fear of Death

Cancer can be a fearsome disease. Most of us have been touched by its cruelty. But our fear of cancer, which in some ways exceeds its danger, takes a terrible toll too. We can't yet cure all cancers, nor can we entirely eliminate the understandable fear of "the emperor of all maladies." But understanding and treating both the disease and our cancerphobia can reduce the enormous cost cancer imposes on us personally and socially.