90% of Women Appear Misinformed About Mammograms, Michael Greger MD, NutritionFacts, 21 September 2021

Most women are just being told what to do, rather than being given the facts needed to make a fully informed decision.

“Selling cancer screening can be easy,” begins an editorial in the Journal of the National Cancer Institute. “Induce fear by exaggerating risk. Offer hope by exaggerating the benefit of screening. And don’t mention harms [caused by the screening]. It is especially easy with cancer—no diagnosis is more dreaded. And, we all know the mantra: early detection is the best protection. Doubt it, and someone may suggest you need your head examined.” And they are not exaggerating, as you can see for yourself at 0:37 in my video Nine out of Ten Women Misinformed About Mammograms, when I show an American Cancer Society pamphlet that actually warns women, “If you haven’t had a mammogram, you need more than your breasts examined.”

“Screening can lead to important benefits, but it can also lead to important harms,” continues the editorial. “A big challenge is conveying the counterintuitive idea that screening does not always help—and can even be harmful. Surveys have shown that most people believe that cancer screening is almost always a good idea and few believe harm [is even] possible.” In patient education materials, “passing reference to potential harms is deceptively buried in a euphoria of benefits.”

The cancer screening test that has been studied most carefully is the mammogram. “In the past 50 years, more than 600,000 women have participated in 10 randomized trials, each involving approximately 10 years of follow-up. Given this extraordinary research effort, it is ironic that screening mammography continues to be one of the most contentious issues within the medical community.” Indeed, in medicine, there are “few fields that invoke more passion…than the question of screening women for the detection of an earlier, more curable stage of breast cancer.” Ironically, both sides accuse the media of being in the opposite camp.

This contentiousness, however, “is in itself instructive.” It should tell us something. “For context, one trial involving fewer than 150 men who were followed for less than 2 years was sufficient to convince physicians of the value of treating severe hypertension.” The benefits of treatment were just so obvious. In contrast, the fact that we’re still debating the merits of mammograms 50 years later, even after 10 trials with 600,000 women, “suggests that the test is surely a close call, a delicate balance between modest benefit and modest harm.” However, that assumes people are weighing the pros and cons objectively. Given the multibillion–dollar industries involved—from the mammogram machine manufacturers to the radiologists who read them—it may be worse than that.

Several organizations publish contradictory cancer screening recommendations. Some recommend mammograms starting at age 40 while others say 50. Some say every year, some say every other year, and some recommend that women shouldn’t get them routinely at all. “There is increasing concern about both financial and emotional conflicts of interest interfering in the generation of guidelines.” People can get so invested in the position they’ve staked out that it may cloud their judgement.

“Reasonable experts agree that the body of evidence suggests that there is some benefit to mammography among women aged 40 years…Although the benefits of mammography screening have certainly been exaggerated, this does not mean that it does not save lives or that women should not get it.” The question is, do the benefits outweigh the risks? That’s a decision each woman has to make for herself, but she can’t do that without knowing all the facts.

Women are so bombarded with information about mammograms, you’d think they would be fairly knowledgeable about them. “Yet nothing is farther from the truth…” Nine out of 10 women surveyed vastly overestimated the benefits of mammograms or had no idea. It’s not the women’s fault, though. They’re obviously being misinformed by the system. Most American women didn’t even appear to understand the basic concept of mammography screening and “believed that screening prevents or reduces the risk of contracting breast cancer” in the first place. This raises doubts about how well women are being informed. It sounds like “women are told what they should do, but without being given the facts necessary to make informed decisions…As a result of paternalism and pink ribbon culture, almost all women have a false impression of the benefit of mammography screening…Most surprisingly, those who frequently consulted their physicians and health pamphlets were slightly worse informed.” It’s as if they were anti–educated by their doctors!

The problem is that these kinds of “inaccurate and exaggerated perceptions of the benefit of screening” prevent women from making an informed choice. “Misleading women, whether intentionally or unintentionally, about the benefit of mammography screening is a serious issue. All of those in the business of informing women about screening should recall that medical systems are for patients, not the other way around.”

“We should not be selling screening. We should be giving people the numbers they need to decide for themselves.”

That’s exactly why I wanted to take on this contentious topic “The question of whether screening mammography does more harm than good has the potential to shake up the state of medical knowledge, alter our views of ethical practice, and alter our application of screening principles. The stakes are high in this discourse because women’s lives hang in the balance.

This article was the first in Dr. Greger’s 14-part series on mammograms. He says, “There’s just so much confusion, combined with the corrupting commercial interests of a billion–dollar industry.” Other topics include: (See the article for links to these topics.)

Mammogram Recommendations: Why the Conflicting Guidelines?
Should Women Get Mammograms Starting at Age 40?
Do Mammograms Save Lives?
Consequences of False-Positive Mammogram Results
Do Mammograms Hurt?
Can Mammogram Radiation Cause Breast Cancer?
Understanding the Mammogram Paradox
Overtreatment of Stage 0 Breast Cancer DCIS
Women Deserve to Know the Truth About Mammograms
Breast Cancer and the Five-Year Survival Rate Myth
Why Mammograms Don’t Appear to Save Lives
Why Patients Aren’t Informed About Mammograms
The Pros and Cons of Mammograms