New guidelines for mammograms released Tuesday by the American Cancer Society represent a major shift from the aggressive early and universal screenings that have been standard practice in the United States for nearly two decades.

The changes, which include recommending that the testing be started later and conducted less frequently, are a recognition of the growing concern that the benefits of mammograms may have been oversold as well as the anxiety and burden to the health care system caused by overdiagnosis and false positives from the tests.

Richard Wender, a member of the breast cancer guideline panel and a former president of the ACS, said that the new recommendations confirm that mammography is the most important thing a woman can do to reduce her chance of dying of breast cancer but that they provide a more “personalized and tailored approach.”

“Over the past couple of years, there has been so much confusion that some women and some clinicians have really lost confidence in mammography. We hope this extraordinary and thorough review will calm that worry,” Wender said.

The more conservative approach outlined by the ACS calls for women starting yearly screening at age 45 instead of 40 and then transitioning to screening every two years starting at age 55 -- which the panel used as a surrogate for menopause. The ACS also recommended that doctors stop screening women with a life expectancy of less than 10 years based on the idea that they will likely die with the cancer but not from it.

In another major change, the ACS recommended skipping the six-minute clinical breast exam where a doctor physically feels around for lumps.

The updates apply only to women of "average risk" who don't have specific risk factors for breast cancer such as the BRCA1 and BRCA2 genetic mutations or a family history of the disease and are not binding on doctors, hospitals, insurers, or individuals. Indeed the ACS noted that women should still "have the opportunity” to undergo the test if they wish to as per the old guidelines.

But some breast cancer patient groups still expressed alarm that they may lead too many women to skip life-saving screenings and provide an excuse for health plans to stop covering them for certain groups.

“We are worried about the message and confusion to the public when they see these new guidelines. The cut back on screening is falsely reassuring,”  said Marisa C. Weiss, an M.D. who is the founder and president of

Judy Salerno, president and CEO of Susan G. Komen, said she's "concerned that they have the potential to lead to reduced accessibility to and coverage for health screenings from both private and public insurers."

The ACS's updates come at a time when cancer experts are rethinking the very definition of cancer. Thanks to advances in genetic testing, blood-based markers and digital imaging, cancer is being diagnosed earlier than ever and there's a radical new recognition that there is a subset tumors that may never grow enough to be harmful to a patient. The most obvious example is in prostate cancers but researchers have found similar cases in cancers of other regions.

Mammograms, X-rays of the breast that have been used for more than a century to pinpoint irregularities in the tissue, are credited with saving many millions of lives by catching cancers at their earliest stages. Breast cancer is one of the leading killers of women in the United States with approximately 225,000 diagnosed each year and 41,000 dying from the disease. In part because of the ubiquitous pink ribbon-themed races, T-shirts and stuffed animals of breast cancer fundraisers and in part because of stories like Angelina Jolie's, many women have come to believe that the more screening and the more treatment the better.

But a number of new studies have questioned this idea.

In July, for example, a reanalysis of data from a pivotal paper based on women in the 1960s and '70s in Sweden showed that screening could reduce deaths around 10 percent -- rather than the 20 percent to 25 percent that had been originally claimed. And in August, a study in JAMA Oncology  found that the overall risk of dying after being diagnosed with so-called stage 0 or ductal carcinoma in situ (DCIS) cancer was 3.3 percent over two decades and that pursuing treatment beyond a lumpectomy did not affect survival.

The ACS is one of a number of organizations whose recommendations are hugely influential in how doctors treat their patients. The American Congress of Obstetricians and Gynecologists (ACOG) still recommends that regular screenings begin at age 40. The U.S. Preventive Services Task Force (USPSTF), an independent panel of experts whose members are appointed by the federal government, reaffirmed their view this April that women between ages 50 and 74 get routine screening once every two years.

The USPSTF recommendations are important because insurers and government programs tend to take their cues from the group and when it first suggested in 2009 that breast cancer screening should begin at 50 instead of 40 the group set off a firestorm of criticism. The ACS was among those who disagreed arguing that the USPSTF "is essentially telling women that mammography at age 40 to 49 saves lives; just not enough of them."

Now, after years of additional research, the ACS has moved closer towards them. That means that now the three different groups are recommending three different ages -- 40, 45, and 50 -- when regular breast cancer screening should begin.

ACOG said that it is convening a conference that will include ACS in January with the goal of creating a consistent set of uniform guidelines for breast cancer screenings.

Nancy L. Keating, a doctor in internal medicine and primary care at Brigham and Women's Hospital who wrote an editorial in JAMA, formerly the Journal of the American Medical Association, accompanying the new guidelines, said the discrepancy shows how controversial the subject of mammograms can be.

In an interview, Keating said that here you have several groups of "very smart people who looked at the same body of literature." "If there were an easy answer they would all have the same conclusions," she said. "It underscores the uncertainty."

Keating said the debate is far from settled elsewhere in the world.

In Britain, screenings are recommended every three years starting at age 47. In Canada, it's age 50 every two years. The United States is one of the only places in the world that recommends annual screening at any age.

"They are saying that they realize we now need to think about the balance of benefits and harms for each individual when we're making decisions about who to test. It’s no longer as simple as saying everybody needs a mammogram," said Keating, who is also in the department of health-care policy at Harvard Medical School.

Wender said that the approach by some countries with national health-care systems is a "resource decision" because they pay for the screenings whereas the threshold in the United States is different because they are guidelines for individuals.

"It reflects the high value that women and the nation have on the opportunity to prevent a cancer death," he said.

Part of the reason for the changes in the guidelines is that a woman's risk of breast cancer increases as they age. Before age 34, their risk is 0.2 percent over five years, 35-39 0.3 percent and 40-44 0.6 percent. But at 45-49 the risk climbs to 0.9 percent, at 45-49 1.1, 50-54 percent 1.1 percent, 55-59 1.3 percent, 60-64 1.6 percent, 65-69 2 percent and 70-74 at 2.1 percent.

Here's a look at the distribution of breast cancer cases and deaths by age at diagnosis, from charts included with the new guidelines in JAMA:

Wender, who is ACS's chief cancer control officer, said that the change in the routine clinical breast examination doesn't mean the organization is telling or asking physicians to stop doing them.

“What the guidelines are saying is that it is mammography that really reduces the risk of breast cancer because it finds them before anybody can feel them," he said.

In looking at the ACS's explanation of its updates, Daniel Kopans, a professor of radiology at Harvard Medical School, noted that the "emotional effects" of being recalled to undergo more testing was one reason given. That's because mammograms can sometimes show areas that look like masses but turn out to be nothing after a second imaging or a biopsy.

"They seem to have wanted to account for the inconvenience of a recall from screening to suggest that some women might prefer to chance an avoidable death for a reduced chance of being recalled for a few extra pictures or an ultrasound," he said.'s Weiss said that one of her main concerns with the new guidelines is that being of "average" or "high" risk is poorly understood and changes over time. Another issue she raised is that the measuring stick or report card for mammography that the ACS used was based on was how long you lived.

"I would prefer to be diagnosed early so I could avoid mastectomy or chemotherapy. It's not just about how long I live," Weiss, a breast cancer survivor, said.

Both Weiss and Kopans said they will not be changing the advice they give to patients on mammograms based on the new guidelines, pointing out that both the ACS and the USPSTF still agree that the most lives are saved by annual screenings at age 40.

"I support the science which is every year starting at age 40," Kopans said. "This is my recommendation."

The full text of the ACS recommendations can be found here.

This post has been updated.

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