Enrique Castro-Mendivi / Reuters

On Tuesday, the influential American Cancer Society further complicated an already mixed set of recommendations about breast cancer screening by releasing revised guidelines about when women should have mammograms.

According to the new guidelines, the ACS suggests that women at average risk for breast cancer can wait until age 45 to undergo their first mammogram and then alternate years starting at age 55. These revisions buck against what many groups  (including the ACS) and cancer awareness initiatives have been recommending for years, namely that women begin screening at age 40 and undergo regular exams by their doctors.

As NBC notes, the new directives also suggest that women forgo clinical breast exams by their doctors altogether so long as they are at average risk. As recently as April, the United States Preventative Services Task Force, a government panel, clarified its guidelines that call for mammograms to begin at age 50, but for individual women to coordinate decisions to screen earlier with their doctors.

When the USPSTF’s 50-and-over recommendation was first made in 2009, it sparked an uproar for not suggesting that women undergo screening in their 40s.

“I am appalled and horrified,” one Sloan-Kettering doctor told Time. “There is no doubt that mammography screening in women in their 40s saves lives. To recommend that women abandon that is absolutely horrifying to me.”

The new ACS guidelines now fall more in line with the assessment that women have been getting screened too early and, sometimes, too often.

“The changes reflect increasing evidence that mammography is imperfect, that it is less useful in younger women, and that it has serious drawbacks, like false-positive results that lead to additional testing, including biopsies,” noted Denise Grady at The New York Times.

As Christie Aschwanden at FiveThirtyEight points out, if there’s one solace here, it’s that other countries offer conflicting assessments on the issue of screening as well:

If you’re a woman living in the U.K., the National Health Service will invite you to come in for mammography screening for breast cancer every three years from age 50 through 69. In Australia, women ages 50 through 74 are advised to undergo screening every two years. Women in Uruguay ages 40 to 59 are obliged to get mandatory mammograms every two years, and in Austria, women are told, “Participation is entirely up to you!”

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