Can radiology duck the blowback in breast cancer screening?

A storm of public anger is brewing. The first signs are the gathering winds of dissent within the medical community against decades of sometimes shrill advocacy for breast and prostate cancer screening, winds that could easily blow up an indignant response from the American public.

An opinion piece published Oct. 21 in the Journal of the American Medical Association detailed the scientific and medical limitations of breast and prostate screening. Dr. Laura Esserman, professor of surgery and radiology and director of the University of California, San Francisco Carol Franc Buck Breast Care Center, and colleagues argue that the benefit from breast and prostate cancer screening falls far short of what it should be. Most disconcerting, this poor track record comes at the cost of overdiagnosis and overtreatment, they wrote.

With this paper and other research indicating that these types of cancer screening have not been as successful as the public has been led to believe, long-time advocates of breast and prostate cancer are waffling. The American Cancer Society last week pulled back from its unflinching support of these two forms of screening, saying that the expected benefits of each have not been fully realized.

“In the case of some screening for some cancers, modern medicine has overpromised,” said Dr. Otis W. Brawley, chief medical officer of the American Cancer Society, and professor of hematology, oncology, and epidemiology at Emory University. “Cancer is a complicated disease and too often we have tried to simplify it and simplify messages about it, to the point that we do harm to those we want to help.”

The root of the problem is that screening methods-most remarkably, from an imaging standpoint, mammography-are finding cancers that do not need to be found. It seems counterintuitive to believe that some cancers are not dangerous or will go away on their own. But a look at the numbers that characterize breast cancer makes this conclusion inescapable.

Despite a substantial increase in diagnosed breast cancers, the incidence of deaths from breast cancer has remained relatively unchanged. One possible reason, simply, is that fatal breast cancers grow too quickly for mammograms to catch in time, leaving ones of lesser or no danger to be found and treated, unnecessarily.

“Without the ability to distinguish cancers that pose minimal risk from those posing substantial risk and with highly sensitive screening tests, there is an increased risk that the population will be overtreated,” the authors wrote.

The problem may be twofold. First, we have acted on the apparently unfounded belief that the use of newer and more sophisticated technologies to find cancers earlier would reduce mortality. Second, we assumed that all breast cancers are the same. This combination has led to an emphasis on detection rather than distinction. The research needed to tell which kinds of breast cancer present the greatest danger has not been done. Esserman and colleagues argue that this research is long overdue and that its results need to be applied to the development of new screening strategies, possibly involving biomarkers that will identify dangerous kinds of breast and prostate cancers.

In the meantime, the public will hear that the message they’ve been given for decades, that breast cancer screening is a no-brainer, requires rethinking. The public response is easy to predict. People who were not convinced by past efforts to boost breast cancer screening will feel vindicated. Many of those who followed past guidelines will feel foolish. The result could be an unprecedented drop in the number of women being screened for breast cancer from the currently extraordinary level of compliance. About 70% of women age 40 or older have had a recent mammogram, according to estimates cited by Esserman and colleagues in the JAMA paper.

The only way out of this mess is transparency, so that women can make informed decisions about screening. First, opinion leaders must publicly admit that the underlying mechanism of breast cancer is not well understood and that breast screening has not made as big a dent in cancer deaths as hoped. Second, they must argue that a major research effort is needed to gain this understanding. Third, healthcare providers and the developers of medical equipment must work together to ensure that the results of this scientific effort lead to the refinement and widespread adoption of technologies that can identify potentially lethal cancers.

“We should want to make screening better,” Esserman said. “For both breast and prostate cancer we need to invest in changing our focus from the cancers that won’t kill people to the ones that do. If we can identify groups of patients that don’t need much treatment, or don’t need to be screened, wouldn’t that be great?”

Great, indeed. But how does the medical establishment get this idea out to the public so it is not interpreted as a slam against breast screening? Esserman’s coauthor Dr. Ian Thompson summarized the potential for misunderstanding.

“People will think that we’re saying screening is bad, and nothing could be further from the truth,” said Thompson, a professor and the chair of the urology department at the University of Texas Health Science Center at San Antonio. “What we are saying is that if you want to stop suffering and death from these diseases, you can’t rely on screening alone.”

This brings us to a critical juncture in healthcare, one at which scientific fact and human behavior must be considered. The conclusions by the JAMA authors about breast screening must be explained clearly-and repeatedly-to the public in the kind of detail that ensures the one-time message in favor of screening does not turn into a convincing argument against it.