Cancer Screening Is Losing 'Luster,' Says Critic

Nick Mulcahy

August 20, 2014

After 50 years of being enthusiastically promoted and used, cancer screening has entered an era that is characterized by "skepticism," according to a commentary published online August 18 in JAMA Internal Medicine.

"The second half of the 20th century was truly an age of wonder for cancer screening," writes essayist Cary Gross, MD, from Yale University in New Haven, Connecticut.

Screening for cervical cancer with the Pap test highlighted this golden period; in the United States, the related incidence and mortality dropped by 60% from the 1950s to the 1990s.

The screening of Americans accelerated in the 1960s as other screening methods were introduced, such as mammography in 1963 and colonoscopy in 1969.

But American clinicians are now full of "wonder" about screening in a very different way, says Dr. Gross. They wonder whether screening helps or hurts patients, what public health messaging should be, and how to relate relevant data.

Prostate cancer screening is emblematic of this shift, he notes, having gone from being "straightforwardly recommended" to being "discouraged by many experts."

"Cancer screening in the 21st losing its luster," Dr. Gross declares in his essay.

"That is a misleading way to describe what's happening," said Richard Wender, MD, chief cancer control officer at the American Cancer Society in Atlanta, who was asked for comment.

Screening is undergoing change and growth, but it still has value when used within guidelines, he told Medscape Medical News.

"In screening, and in medicine in general, we are increasingly able to communicate limitations, benefits, and risks," Dr. Wender said. These details are inherently complicated and challenging, even for clinicians, he noted.

Furthermore, the practice of oncology continues to learn from screening and refine subsequent patient management, he said. "Before the PSA test, we knew nothing about how to treat early prostate cancer because we never saw it."

"Through screening, we found a stage of cancer that we never knew existed," he added.

The current state of cancer screening reflects these evolutions in evidence and treatment, he explained. "It's not simple," he said.

As proof that screening can be highly effective, Dr. Wender described the "43% reduction in mortality from colorectal cancer in the past few decades." From 2000 to 2010 in the United States, there was also a 30% drop in the incidence rate, he reported.

That is something to shout to the hills.

"That is not a loss of luster. That is something to shout to the hills," he said.

The reduction in colorectal cancer (CRC) mortality is "absolutely due to screening" and "not better treatment" or "better diet." In fact, "our diet has gotten worse," said Dr. Wender.

Dr. Gross emphasized to Medscape Medical News that CRC screening is "an effective test for younger people," but explained that "age has a very strong impact on efficacy."

He observed that, in the United States, CRC screening is being used in many older patients with negligible benefit.

That is a problem with cancer screening in general in the United States, according to a large population-based study also published online August 18 in JAMA Internal Medicine, as reported by Medscape Medical News.

Researchers analyzed data from the National Health Interview Survey and found that more than half of all people 65 years and older who had a life expectancy of less than 9 years had received prostate, breast, cervical, or CRC screening.

Screening in older people with limited life expectancies is in conflict "with several guidelines," writes Dr. Gross.

It's not always clear who the right people are.

Despite their different perspectives on the current state of screening, Dr. Gross and Dr. Wender agree that screening should only be done in appropriately selected adults.

"It's time to end non-evidence-based screening," said Dr. Wender.

"I agree, we need to screen the right people," said Dr. Gross. But he suggested that this sentiment is at the crux of the murkiness about screening and the related increase in skepticism. "It's not always clear who the right people are," he said.

Tipping Point

We don't want the pendulum to swing back so far that no one gets screened.

Much is at stake in the current era of cancer screening, said Dr. Gross.

"We don't want the pendulum to swing back so far that no one gets screened," he told Medscape Medical News.

He extended the metaphor about balance by saying that the United States is at a "tipping point" with cancer screening — with the "credibility" of the enterprise at risk.

"For years, cancer screening has been oversold," he said, echoing a comment made by Otis Brawley, MD, chief medical officer of the American Cancer Society, in 2009, which caused a firestorm of controversy at that time.

This declaration has become less controversial since a variety of commentators have described screening as being the subject of promotion instead of education.

"We will look back at the past 25 years and see it as a period of irrational exuberance," said Dr. Gross.

Change is possible and necessary, he added.

In his essay, Dr. Gross argues that we will "truly" have a "new era" of screening when healthcare providers are evaluated in part by their "ability to refrain from ordering cancer screening tests for some of their patients."

Such quality measurement would address overscreening, he said. And it might be underway. The National Committee for Quality Assurance has proposed that in 2015, screening for CRC in people 86 years and older and for prostate cancer in men 70 years and older be considered overuse.

Communications are also a key to improving screening. There is "a lot of conversation" surrounding the decision about heart bypass surgery. "I would argue that cancer screening merits the same kind of conversation," said Dr. Gross.

Clinicians should have a "cheat sheet" of the absolute numbers related to screening, including the number of adults needed to screen to prevent 1 cancer-related death, he said. Absolute numbers are more easily comprehended than relative percentages, he noted.

Professional societies also need to develop "rigorous estimates" of benefits and risks for specific screening methods and disseminate them to membership, he added.

"We need patient-centered, outcomes-conscious cancer care," Dr. Gross concluded.

Dr. Gross is a member of the scientific advisory board for FAIR Health, and receives research funding from Medtronic and Johnson & Johnson as part of a clinical trial data-sharing project.

JAMA Intern Med. Published online August 18, 2014. Abstract


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