“Err on the side of caution – except where radiation is involved.”

That could be the tagline for a new report just published in JAMA Internal Medicine. A study has shown that over 80 percent of doctors are still recommending annual mammograms for women in their early 40s, even though guideline changes have pushed back the age for yearly breast cancer screening.

The American Cancer Society urges that annual screening starting at age 45 and screening every other year from age 55 onward. Odds are your doctor is also ignoring the advice of the U.S. Preventive Services Task Force (USPSTF), a volunteer body that helps set standards for preventive care. The USPSTF recommends that women aged 50 to 74 receive mammograms every other year.

In short, the benefits of frequent mammography needs to be weighed against the risk associated with not only the exposure to additional radiation, but also the higher likelihood of a false positive.

"The false positive may result in some anxiety for the patient, but it definitely will result in additional testing," said Dr. Deborah Grady, a professor of epidemiology with the University of California, San Francisco, School of Medicine. The testing, in turn leads to yet more radiation, or the scheduling of a biopsy.

The slope gets slipperier still as additional mammograms can lead to a greater risk of over-diagnosis in these women. For example, the test-happy doctor may find a cancer that poses no immediate health risk but now must be addressed with lumpectomy, radiation therapy or even hormone therapy.

"If you go looking in people with a very low risk of disease, most of the cancers you find will be an over-diagnosis, a cancer that was never going to cause them any problem," Grady said.

Women have been conditioned to want to be screened every year for breast cancer, regardless of their age. It’s the “right thing to do,” like meeting with a dentist twice a year.

"There's this innate human feeling that if we should do it in these people, why not do it in more people – the whole thinking that more is better," Grady said. "But in medicine, in many ways that can be dangerous. More is not always better."

What’s the solution? It may ultimately be in the hands of the insurers. If they no longer pay for tests that the American Cancer Society warns against, it is likely fewer doctors will be scheduling them