A new study found that screening women over 65 for breast cancer may only lead to more false positives, and not detect more tumors.
The American Cancer Society currently recommends that women get annual mammograms starting at age 40.
Experts say the study could lead to new guidelines, although they note that previous studies have produced conflicting results.
This latest study was conducted by researchers at the University of California, San Francisco, and is published in the journal of the National Cancer Institute.
One in eight women has been diagnosed with breast cancer in the U.S.